JPWO2006085626A1 - Exposure method and apparatus, and device manufacturing method - Google Patents

Abstract

An exposure apparatus that improves the line width uniformity of a pattern image exposed on an object such as a substrate. In an exposure apparatus that exposes the wafer (121) through the reticle (119) and the projection optical system (120) with illumination light (IL) from the light source (101), the reticle (119) is illuminated with illumination light (IL). A digital micromirror device (128) as a reflection element array including a plurality of mirror elements each capable of controlling the reflection direction of illumination light (IL) is disposed at a position almost conjugate with the reticle (119) in the illumination optical system. The illuminance distribution in the illumination area on the reticle (119) is controlled by independently controlling the reflection angle of each mirror element of the digital micromirror device (128).

Description

  The present invention relates to an exposure technique for exposing an object with an exposure beam. More specifically, for example, a photolithography process for manufacturing various devices such as a semiconductor element, a liquid crystal display element, an imaging element (CCD, etc.), and a thin film magnetic head. The present invention relates to an exposure technique used for transferring a mask pattern onto a substrate.

  In a photolithography process in a manufacturing process of a device such as a semiconductor element or a liquid crystal display element, a circuit pattern formed on a reticle (or a photomask) as a mask is transferred to a photosensitive material (photoresist etc.) as a substrate through a projection optical system. Projection exposure apparatus for projecting onto a wafer or glass plate coated with (). As such a projection exposure apparatus, a step-and-repeat type static exposure type (collective exposure type) exposure apparatus (for example, a so-called stepper) and a step-and-scan type scanning exposure type exposure apparatus (for example, a so-called scanning stepper). ) Etc. are used.

  For example, as one basic function in a projection exposure apparatus used in a manufacturing process of a semiconductor device, an exposure amount for keeping an integrated exposure amount (integrated exposure energy) for each point in each shot area of a wafer within an appropriate range. There is a control function. In a static exposure type exposure apparatus such as a stepper, the exposure amount control method is the basic regardless of whether a continuous light source such as an ultra-high pressure mercury lamp or a pulsed laser light source such as an excimer laser light source is used as an exposure light source. In particular, cut-off control was employed. In this cut-off control, a part of the exposure light is branched during exposure light exposure to the wafer coated with the photosensitive material and led to a photoelectric detector called an integrator sensor, and indirectly through this integrator sensor. Control is performed such that the amount of exposure on the wafer is detected and laser emission is continued until the integrated value of the detection result exceeds a predetermined level (critical level) corresponding to the integrated exposure amount required for the photosensitive material. Done. Specifically, when the exposure light is continuous light, control is performed such that the optical path of the exposure light is closed by a shutter when the integrated exposure amount exceeds a critical level.

  On the other hand, in a scanning exposure type exposure apparatus such as a scanning stepper, the above-described cut-off control cannot be applied because exposure amount control focusing on only one point on the wafer cannot be applied. Therefore, when the exposure light source is a pulse laser light source, a method (open exposure amount control method) in which the exposure amount control is performed by simply integrating the amount of each pulse illumination light is used as the first control method. . As a second control method, for example, as disclosed in Japanese Patent Laid-Open No. 6-252022, a slit-shaped exposure region on a wafer (a region conjugate to a slit-shaped illumination region on a reticle is used. The wafer is scanned relative to this exposure area.) A method of measuring the integrated exposure amount for each pulse illumination light in real time and controlling the target energy of the next pulse illumination light based on the integrated exposure amount ( A pulse-by-pulse exposure control system) is also used.

  In the wafer process of the semiconductor device manufacturing process, the circuit pattern is obtained by repeating the processes such as oxidation of the wafer surface (wafer surface), formation of an insulating film, electrode deposition, ion implantation, exposure, and etching many times. It is formed. In this process, when the wafer size is increased from 6 inches (150 mm) to 8 inches (200 mm), and further to 12 inches (300 mm), the coating thickness of the photosensitive material is not uniform within the wafer surface. It may become. Further, even in the stage of developing the photosensitive material on the exposed wafer, a difference in development characteristics may occur depending on the location on the wafer surface. For these reasons, there is a problem that the pattern line width shifts and the resolution defect occurs due to the position of the shot area in one wafer and also the position in the shot area, resulting in a decrease in product yield. In order to solve this problem, in a scanning exposure type exposure apparatus, a method has been proposed in which the amount of light of pulse illumination light is adjusted according to the position on the wafer to correct the amount of light irradiated to the photosensitive material ( For example, see Patent Document 1).

In the scanning exposure type exposure apparatus, the integrated exposure amount at each point in each shot area on the wafer is an integral value of illuminance in the scanning direction (short direction) of the slit-shaped illumination area. Therefore, in order to control the integrated exposure amount at each point on the wafer, an exposure apparatus has been proposed in which the width in the scanning direction of the illumination area is variable by a mechanical mechanism for each of a plurality of positions in the non-scanning direction. (For example, refer to Patent Document 2).
Japanese Patent No. 3093528 Japanese Patent Laid-Open No. 10-340854

  In recent years, there is an increasing demand for a system LSI in which a large number of functions are integrated on a single chip to have many functions. The system LSI has a structure in which single-function circuits are assembled according to the application. With this structure, for example, a logic circuit and a memory circuit can be included in one chip, and a chip having characteristics of logic and memories such as DRAM, SRAM, and NVRAM (Non-Volatile RAM) can be manufactured. Such a semiconductor chip complicates the manufacturing process, and it is often necessary to optimize the process for each different circuit. For example, since the circuit dimensions sensitively affect the characteristics of each circuit, the optimum circuit dimensions differ between the logic portion and the memory portion on the same chip. In the future, as the degree of integration increases and the manufacturing accuracy (line width uniformity) of each circuit pattern will become stricter, as the number of circuits with different functions incorporated on the same chip increases, each shot area There is a problem that it becomes difficult to transfer a pattern with a desired line width uniformity for each of the circuits having different functions.

  Further, due to non-uniformity of the coating thickness and / or development characteristics of the photosensitive material within the wafer surface, the pattern line width varies depending on the position of the shot area and the position within the shot area on a single wafer. With respect to the problem that a shift or poor resolution occurs and the device yield decreases, the method of adjusting the amount of pulsed illumination light according to the position on the wafer as disclosed in Patent Document 1 described above is non-scanning. There is a problem that the light quantity distribution in the direction cannot be corrected.

In addition, in order to control the exposure amount distribution in the non-scanning direction, the method disclosed in Patent Document 2 in which the width in the scanning direction of the illumination region is variable by a mechanical mechanism for each position in the non-scanning direction, Therefore, it is difficult to change the width of the illumination area at high speed during stepping movement between shot areas or during exposure of one shot area.
The present invention has been made under such circumstances, and a first object thereof is to provide an exposure technique capable of improving the line width uniformity of an image of a pattern exposed on an object such as a substrate. .

A second object of the present invention is to provide an exposure technique capable of improving the line width uniformity of a pattern image exposed on an object such as a substrate when performing scanning exposure.
Another object of the present invention is to provide a device manufacturing technique using such an exposure technique.

  An exposure apparatus according to the present invention is an exposure apparatus that exposes an object with an exposure beam from a light source. The exposure apparatus includes a plurality of reflecting elements each capable of controlling a reflection direction of the exposure beam, and in an illumination area of the exposure beam on the object. A reflection element array arranged between the light source and the object for adjusting the illuminance distribution, a storage device storing exposure amount control data for controlling the exposure amount for the object, and the storage device And a control device for controlling the reflective element array based on the stored exposure amount control data.

According to the present invention, the illuminance distribution of the illumination area on the object can be controlled by independently controlling the reflection direction of the exposure beam by the individual reflecting elements of the reflecting element array. Therefore, since exposure can be performed with an optimum exposure amount for each of a plurality of local regions in the illumination region, the line width uniformity of the pattern image exposed on the object can be improved.
When the object is exposed through a predetermined pattern, for example, the illuminance distribution in the illumination area of the exposure beam on the pattern is controlled. In the case of batch exposure, as an example, when the integrated exposure amount for each local region on the object reaches an appropriate exposure amount, the reflective element that illuminates the local region is controlled, and thereafter It is only necessary that the area is not illuminated with the exposure beam. As a result, exposure can be performed with an optimum exposure amount for each local region on the object.

  In the present invention, as an example, the reflective element array is a digital micromirror device (DMD). In the digital micromirror device, for example, several hundreds of thousands to several millions of minute reflecting elements capable of electrically controlling the tilt angle independently are laid in a matrix on a substrate such as silicon. In addition, as the reflective element array, a digital micromirror device currently used in, for example, a projector can be used.

  Further, as an example, each of the reflecting elements constituting the reflecting element array reflects the exposure beam in one of the first and second reflecting directions, and the exposure beam from the light source is reflected on the reflecting element array. You may further provide the beam splitter which guides, and the aperture member which light-shields the exposure beam reflected in the 2nd reflection direction. In this case, by switching the reflection direction of each reflection element to the first or second reflection direction, irradiation or non-irradiation of the exposure beam from each reflection element to the object can be switched. Therefore, the local illumination distribution on the object can be controlled at high speed with a simple configuration.

The exposure amount control data may be set so that the line width distribution of the pattern image formed on the object has a predetermined distribution. Thereby, the line width uniformity of the pattern image can be further improved.
Further, when the object is a substrate coated with a photoconductor, the exposure amount control data includes at least one of nonuniformity in the coating thickness of the photoconductor and nonuniformity in development characteristics depending on the position on the substrate. May be set so as to correct. As a result, it is possible to improve the deterioration of the line width uniformity due to the uneven coating thickness or the development characteristics of the photoreceptor.

  The reflective element array can be disposed at a position substantially conjugate with the object between the light source and the object, or at a position shifted by a predetermined amount from the substantially conjugate position. When the reflective element array is disposed at the substantially conjugate position, the illuminance distribution on the object is determined according to the distribution in the reflection direction of the exposure beam of the reflective element array, so that the illuminance distribution can be easily controlled. . On the other hand, when the reflecting element array is shifted from the substantially conjugate position by a predetermined amount, the image of the boundary portion of each reflecting element of the reflecting element array is not projected onto the object, thereby reducing illuminance unevenness. May be.

In addition, the image processing apparatus further includes an arithmetic device that calculates an integrated exposure amount of the exposure beam for the object during the exposure of the object, and the control device is based on the integrated exposure amount determined by the arithmetic device and the exposure amount control data, The reflective element array may be controlled. Thereby, the integrated exposure amount on the object can be controlled with high accuracy.
As an example, the exposure apparatus is a scanning exposure type that moves the object relative to the exposure beam during the exposure of the object.

When the exposure apparatus is a scanning exposure type as described above, the exposure apparatus further includes a position detection apparatus that measures position information of the object in the scanning direction, and the control apparatus includes the position information obtained by the position detection apparatus and the exposure amount thereof. The reflective element array may be controlled based on the control data. Thereby, the line width uniformity of the pattern image exposed on the object after scanning exposure can be improved.
Further, the exposure amount control data may be set so that the integrated light amount value in the scanning direction of the illumination area of the exposure beam is substantially uniform over the non-scanning direction orthogonal to the scanning direction. In this case, the distribution of the integrated exposure amount on the object after scanning exposure becomes uniform. Of course, the exposure amount control data can also be set so that the distribution of the integrated light amount value in the non-scanning direction becomes non-uniform.
As an example, the reflective element array includes a plurality of reflective elements arranged in one or more lines in a region corresponding to a predetermined position in the scanning direction of the illumination region of the exposure beam. In this case, the one or a plurality of reflecting elements arranged in a line are arranged substantially in parallel in the non-scanning direction orthogonal to the scanning direction of the object, for example. Thereby, the distribution of the integrated exposure amount after the scanning exposure can be controlled only by using an elongated and small reflective element array.

The control device may control the reflective element array to control the width of the illumination region of the exposure beam in the scanning direction. This makes it possible to control the width of the illumination area at a high speed and with a fine pitch with higher reproducibility than when mechanically controlling the width of the field stop of the illumination optical system. Can be controlled with high accuracy.
The exposure amount control data may be set for each of a plurality of partitioned areas on the object. Thereby, for example, even when the optimal exposure amount distribution differs for each of the plurality of partitioned areas on the object, the distribution of the exposure amount can be optimized for each partitioned area.

  Next, an exposure method according to the present invention is an exposure method in which an object is exposed by irradiating an exposure beam from a light source, and at least an exposure amount and an exposure amount distribution for each of a plurality of partitioned regions on the object. A reflection element array including a plurality of reflection elements arranged between the light source and the object and capable of controlling the reflection direction of the exposure beam; And a second step of controlling the illuminance distribution in the illumination region of the exposure beam on the object based on the exposure amount control data.

According to the present invention, by controlling the reflection direction of the exposure beam by the individual reflecting elements of the reflecting element array independently of each other, an optimal illuminance distribution can be obtained for each of a plurality of local areas in the illumination area. Exposure can be performed. Therefore, the line width uniformity of the pattern image exposed on the object can be improved.
A device manufacturing method according to the present invention uses the exposure apparatus or exposure method of the present invention. By applying the present invention, it is possible to improve the line width uniformity of an image of a pattern exposed on an object, so that a device having a configuration in which a plurality of circuits having different functions are combined like a system LSI can be manufactured with high accuracy.

  According to the present invention, exposure can be performed with an optimum exposure amount for each local region on an object. Accordingly, it is possible to improve the line width uniformity of the pattern image exposed on the object such as the substrate.

It is a figure which shows schematic structure of the projection exposure apparatus of the 1st Embodiment of this invention. It is a figure which shows the exposure amount map on the reticle of 1st Embodiment. It is a figure which shows the reflective surface of DMD128 of FIG. 1 corresponding to the exposure amount map of FIG. (A) is a figure which shows an example of the illumination intensity distribution of the exposure area | region on a wafer, (b) is a figure which shows the correction | amendment exposure amount map for correct | amending the illumination intensity distribution of Fig.4 (a). (A) is a figure which shows exposure amount distribution which should be corrected on the wafer resulting from a resist process, (b) is a figure which shows the correction | amendment exposure amount map on the reticle corresponding to Fig.5 (a). (A) is a figure which shows an example of the change of the integrated exposure amount of 1st Embodiment, (b) is a figure which shows the change of the energy per unit time corresponding to Fig.6 (a). It is a figure which shows schematic structure of the projection exposure apparatus of the 2nd Embodiment of this invention. It is a perspective view which shows the optical path from the reflective mirror 11 of FIG. 7 to the reticle R. It is a perspective view which shows the structure of the mirror element part D1, D2 of the reflective mirror 11 of FIG. It is a figure which shows the exposure amount map on the reticle R of 2nd Embodiment. It is a top view which shows the change of the relative position of the reticle R of FIG. 10, and the illumination area | region 42R. FIG. 12 is a perspective view showing an ON or OFF state of each mirror element of the mirror element portion D1 of the reflection mirror 11 of FIG. 7 at time t ₁ of FIG. It is a perspective view showing the on or off state of each mirror element of the mirror element D1 of the reflecting mirror 11 in FIG. 7 at time t ₂ in FIG. 11. When proper exposure amount is gradually increased, is a perspective view showing the on or off state of each mirror element of the mirror element D1 of the reflecting mirror 11 in FIG. 7 at time t ₂ in FIG. 11. (A) is a figure which shows the exposure amount distribution which should be correct | amended on the wafer resulting from a resist process, (b) is a figure which shows the correction | amendment exposure amount map on the shot area corresponding to Fig.15 (a). (A) is a figure which shows an example of the illumination intensity distribution of the exposure area | region on the wafer at the time of scanning exposure, (b) shows the integrated exposure amount distribution of the non-scanning direction after scanning exposure with the illumination intensity distribution of Fig.16 (a). FIG. (A) is a figure which shows an example of the illumination intensity distribution at the time of controlling the width | variety of the exposure area | region on the wafer at the time of scanning exposure, (b) is a non-scanning direction after scanning exposure with the illumination intensity distribution of Fig.17 (a). It is a figure which shows integrated exposure amount distribution. It is a figure which shows schematic structure of the projection exposure apparatus of the modification of 2nd Embodiment. FIG. 19 is a perspective view showing an optical path from the reflecting mirror 11 to the reticle R in FIG. 18. 18A is a diagram showing an illuminance distribution in the scanning direction of the illumination region 42R when all the mirror element portions D3 are turned on in the projection exposure apparatus of FIG. 18, and FIG. 18B is a mirror element portion in the projection exposure apparatus of FIG. It is a figure which shows the illumination intensity distribution of the scanning direction of the illumination area | region 42R when all D3 is made into an OFF state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Reflection mirror, D1, D2, D3 ... Mirror element part, 12 ... Illumination system, 13 ... Beam splitter, 16 ... Excimer laser light source, 33 ... DMD drive device, 37 ... Condenser lens, PL ... Projection optical system, R ... Reticle, W ... wafer, SA ... shot area, 42R ... illumination area, 42W ... exposure area, 50 ... main control device, 51 ... storage device, 54W ... laser interferometer, 55 ... light shield, 101 ... mercury lamp, 126 ... Beam splitter, 127 ... condenser lens, 128 ... digital micromirror device (DMD), 129 ... light shield, 119 ... reticle, 120 ... projection optical system, 121 ... wafer, 125 ... main control system, 130 ... storage device, 131 ... DMD drive

[First Embodiment]
A preferred first embodiment of the present invention will be described below with reference to FIGS. In this example, the present invention is applied when exposure is performed by a projection exposure apparatus including a stepper as a batch exposure type exposure apparatus.
FIG. 1 shows a schematic configuration of the projection exposure apparatus of this example. In FIG. 1, a mercury lamp 101 is used as a light source for exposure. However, as an exposure light source, an excimer laser such as KrF (wavelength 248 nm) or ArF (wavelength 193 nm), an F ₂ laser (wavelength 157 nm), a harmonic generator of a YAG laser, or a solid-state laser (semiconductor laser, etc.) A harmonic generator or the like can also be used. The illumination light IL as the exposure beam from the mercury lamp 101 is collected by the elliptical mirror 102, and then includes a collection optical system 103a and an optical filter 103b for selecting light (for example, i-line) in a desired wavelength band. The light reaches the shutter 104 through the optical filter system 103. The shutter 104 is opened and closed by a shutter control mechanism 105 based on a command from the timer control system 106. When the shutter 104 is in the open state, the illumination light IL becomes a substantially parallel light beam via the input lens 107 and enters the fly-eye lens 108 as an optical integrator (a homogenizer or a homogenizer).

  A large number of secondary light source images are formed on the exit surface of the fly-eye lens 108 (the pupil plane of the illumination optical system), and the illuminance distribution of the illumination light IL that illuminates the reticle 119 is thereby flattened. The illumination light IL that has passed through the fly-eye lens 108 is incident on a beam splitter 109 having a reflectance of about 98%. The illumination light IL reflected by the beam splitter 109 passes through the first relay lens 113 and passes through a predetermined variable illumination area on the illumination blind (variable field stop) 114 whose aperture shape is controlled by the blind drive system 115. Limited to luminous flux to illuminate. A main control system 125 that controls the operation of the entire apparatus controls the shape of the opening of the illumination blind 114 and the shape of the illumination area on the reticle 119 via the blind drive system 115. The illumination light IL that has passed through the illumination blind 114 is reflected by a digital micromirror device (hereinafter referred to as DMD) 128 as a reflective element array via the second relay lens 116, the beam splitter 126, and the condenser lens 127. Illuminate the surface with a uniform illumination distribution. As will be described later, the DMD 128 includes a large number of mirror elements as minute reflecting elements having a variable tilt angle of the reflecting surface. The reflecting surface of the DMD 128 is conjugate with the pattern surface (pattern forming surface) of the reticle 119 as a mask. In the right position. The main control system 125 controls the tilt angles of the reflecting surfaces of the individual mirror elements of the DMD 128 independently of each other via the DMD driving device 131 (control device).

  The reflected light from the DMD 128 passes through the condenser lens 127 and the beam splitter 126 again, and enters the light blocking body 129 having a circular opening 129a formed at the center as a diaphragm member. Instead of the light shielding body 129, an absorber that absorbs light may be used. Illumination light IL reflected in a predetermined direction from a number of mirror elements of DMD 128 passes through opening 129a of light shield 129, and then illuminates the pattern in the illumination area of the pattern surface of reticle 119 via condenser lens 118. .

  At least a part of a light source device for exposure is configured including a mercury lamp 101, an elliptical mirror 102, and a condensing filter system 103, and includes a shutter 104, an input lens 107, a fly-eye lens 108, a beam splitter 109, and a first relay lens. 113, an illumination blind (variable field stop) 114, a second relay lens 116, a beam splitter 126, a condenser lens 127, a DMD 128, a light shield 129, and a condenser lens 118 constitute at least a part of the illumination optical system. Yes.

  Under the illumination light IL, the pattern in the illumination area of the reticle 119 is projected on both sides (or one side) through the telecentric projection optical system 120 (β is a reduction magnification such as 1/4, 1/5, etc.). Then, projection exposure is performed on an exposure area on one shot area of the wafer 121 coated with a photoresist (photosensitive material or photosensitive material) as a substrate. The surface of the wafer 121 is partitioned into a number of rectangular shot regions (partition regions) onto which the pattern image of the reticle 119 is transferred. The illumination area on the reticle 119 and the exposure area on the wafer 121 are conjugate, and the exposure area on the wafer 121 can be regarded as an illumination area. The wafer 121 is a disk-shaped substrate having a diameter of about 200 to 300 mm, such as a semiconductor (silicon or the like) or SOI (silicon on insulator).

  In this example, since the reflection surface of DMD 128 and the pattern surface of reticle 119 are arranged at optically conjugate positions, the distribution of the reflected light of illumination light IL by each mirror element constituting DMD 128 is almost as it is. This corresponds to the illuminance distribution of the illumination area 119 (or the exposure area on the wafer 121). However, when the boundary of each mirror element on the DMD 128 is projected in a grid pattern on the pattern surface of the reticle 119 and the illuminance distribution may be out of the allowable range, the DMD 128 reflection surface is conjugate with the pattern surface of the reticle 119. You may arrange | position in the position which shifted | deviated only predetermined amount from the position (here the illumination intensity distribution is settled in the tolerance | permissible_range).

  In the illumination optical system, the illumination light that has passed through the beam splitter 109 is incident on an integrator sensor 111 that is an optical sensor for photoelectric conversion via a condenser lens 110, and this output signal is supplied to an illuminance calculation system 112. The For example, the integrator sensor 111 is located at a position substantially conjugate with the pattern surface of the reticle 119. For example, when the circuit pattern is not formed on the reticle 119 (transmittance is 1), the conversion coefficient between the exposure energy per unit time on the wafer 121 and the illuminance on the integrator sensor 111 is preliminarily calculated. Is remembered. In the illuminance calculation system 112, the exposure energy (illuminance) per unit time on the wafer 121 is obtained by multiplying the output signal of the integrator sensor 111 by the conversion coefficient. The obtained exposure energy per unit time is supplied to the main control system 125 (arithmetic unit for obtaining the integrated exposure amount). Further, the exposure time obtained by dividing the appropriate exposure amount on the wafer 121 (photoresist) by the exposure energy per unit time at the time of exposure is input to the timer control system 106. In response to this, the timer control system 106 can control the exposure amount on the wafer 121 by opening the shutter 104 for the exposure time as an example.

However, in this example, as described later, also in the DMD 128, the exposure time (integrated exposure amount) for each illumination light reflected by each mirror element can be controlled by controlling the reflection angle of each mirror element.
In addition, a plurality of partial regions (local regions) PTi (i = 1, 2,...) Having different pattern characteristics (pattern line width, pattern repetition period (pitch), pattern density, etc.) exist on the reticle 119. In other words, the integrated exposure amount is controlled for each of the plurality of partial areas PTi on the reticle 119. Therefore, for each partial area PTi on the reticle 119, an appropriate exposure amount Pi determined in accordance with the characteristics of each partial area PTi is obtained. Then, by dividing the appropriate exposure amount Pi for each partial region PTi by the exposure energy E per unit time on the wafer 121, the exposure time ti (i = 1, 2, 3,...) For each partial region PTi is obtained. It is done.

That is, there is the following relationship.
ti = Pi / E (i = 1, 2,...) (1)
The exposure energy E per unit time on the wafer 121 can be determined by measuring the average exposure energy reaching the image plane side of the projection optical system PL before starting the exposure of the wafer 121. Further, in this embodiment, the longest time ti _max in exposure time ti is supplied to the timer control system 106, the shutter 104 is closed when the maximum exposure time ti _max has elapsed.

  In this example, the exposure to the partial region PTi is stopped when the integrated value of the exposure energy ΔE per unit time measured via the integrator sensor 111 reaches the appropriate exposure amount Pi. That is, the main control system 125 controls the tilt angle of each mirror element of the DMD 128 based on the integrated value of the exposure energy ΔE per unit time measured via the integrator sensor 111, and integrated exposure of each partial region PTi. The exposure time is controlled for each partial region PTi so that the amount becomes the appropriate exposure amount Pi. Thereby, the integrated exposure amount is optimized according to the pattern characteristics on the reticle 119, and the line width uniformity of the pattern image in the shot area can be improved.

  When the shot area on the wafer 121 is exposed through the reticle 119 having a plurality of partial areas PTi having different pattern characteristics as described above, it corresponds to the partial area PTi on the reticle 119 during the exposure of the shot area. By controlling (adjusting) the illuminance distribution in the illumination area, the integrated exposure amount can be optimized for each local area in the shot area corresponding to the partial area PTi.

  The appropriate exposure amount Pi for each partial region PTi on the reticle 119 is stored in advance in the storage device 130 connected to the main control system 125 as exposure amount map information. The exposure map information is created based on the measurement result by, for example, transferring the pattern on the reticle 119 onto the test wafer, measuring the line width of the pattern image formed on the test wafer, and the like. This is data obtained so that each pattern has a desired line width in the shot area (first step).

  Further, in the storage device 130, as will be described later, a pattern line after development caused by uneven illumination intensity of the illumination light IL by the illumination optical system, uneven coating thickness of the photoresist on the wafer 121, and uneven development. A correction map including a corrected exposure amount that is added (subtracted when the value is negative) to the integrated exposure amount to correct a change in width is also stored. The correction map is set for each shot area on the wafer 121 as an example, but may be set for each partial area obtained by further dividing each shot area. At the time of exposure, the main control system 125 uses the illumination light IL in order to obtain a desired distribution of the integrated exposure amount of each shot area on the wafer 121 based on the exposure amount map and the correction map stored in the storage device 130. Control irradiation. As an example, during the exposure of each shot area, illumination for each partial area so that the distribution of the integrated exposure amount obtained by adding the exposure amount determined by the correction map to the appropriate exposure amount determined by the exposure amount map described above. The illuminance distribution of the light IL is controlled (second step). The control of the illuminance distribution in this case includes at least one of the control of the illuminance distribution in the illumination area on the reticle 119 and the control of the illuminance distribution in the shot area on the wafer 121.

  Hereinafter, the Z-axis is taken in parallel to the optical axis AX of the projection optical system 120, the X-axis is taken in a direction perpendicular to the paper surface of FIG. 1 within a plane perpendicular to the Z-axis, and the Y-axis is taken in a direction parallel to the paper surface of FIG. Take the axis and explain. At this time, the reticle 119 is sucked and held on the reticle stage 132, and the reticle stage 132 positions the reticle 119 in an XY plane on a reticle base (not shown). A laser interferometer system (not shown) for measuring the position of the reticle stage 132 in the XY plane is also provided.

  On the other hand, the wafer 121 is sucked and held on the wafer stage 133 via a wafer holder (not shown), and the wafer stage 133 moves stepwise in the X and Y directions on the XY plane on the wafer base 134 to position the wafer 121. I do. A laser interferometer system (not shown) for measuring the position of the wafer stage 133 in the XY plane is also provided. The main control system 125 performs positioning of the reticle stage 132 and step movement of the wafer stage 133 based on the measurement values of these laser interferometer systems. A reticle alignment microscope (not shown) for aligning the reticle 119 and an alignment sensor (not shown) for aligning the wafer 121 are also provided.

  During exposure of the wafer 121, the illumination light IL is irradiated onto the reticle 119, the pattern of the reticle 119 is transferred to one shot area on the wafer 121 via the projection optical system 120, and the wafer stage 133 is driven. The operation of moving the wafer 121 stepwise in the X and Y directions and moving the next shot area on the wafer 121 to the exposure area of the projection optical system 120 is repeated.

  Now, when each shot area on the wafer 121 is exposed with an image of a pattern in the illumination area of the reticle 119, even if the pattern characteristics are different in a plurality of partial areas in the illumination area, By controlling the exposure time of the illumination light IL for a plurality of partial areas, the integrated exposure amount in each shot area can be set to a desired distribution. First, the configuration of DMD128 (digital micromirror device) as a reflective element array used for the exposure amount control will be described.

  As an example, the DMD 128 has hundreds of thousands to hundreds of minute mirror elements (reflective elements) that can electrically control the tilt angle of the reflecting surface independently of each other at a predetermined pitch in the X and Y directions on the lower surface of the silicon substrate. About 10,000 pieces are laid down. In this case, the mirror element is divided so that the illumination area on the reticle 119 is divided into a number of minute portions in the X and Y directions, and the illumination light from the corresponding mirror element of the DMD 128 is irradiated to each minute portion. Arranged in a matrix.

  As the DMD 128, a digital micromirror device (DMD) that is currently widely used in projectors and the like can be used. When the DMD is used for a projector, each mirror element changes its tilt angle by about ± 12 °. In this case, as an example, the tilt angles of + 12 ° and −12 ° correspond to the on state and the off state, respectively, and each mirror element is turned on and off in a cycle of several thousand times per second by digital control. Switching is possible. When each mirror element is irradiated with light from the light source, for example, the light reflected by the mirror element at −12 ° (off state) is absorbed by the light absorbing plate arranged separately, and the mirror at + 12 ° (on state) The light reflected by the element is irradiated on the screen through the projection lens. The density of the projected image is expressed by controlling the number of on / off operations of a large number of mirror elements on the DMD.

In this example, the DMD is used to irradiate a reticle 119 instead of the screen. At present, a DMD that is generally available has 720 × 1280 mirror elements. Therefore, if the size of the shot area on the wafer (shot size) is 20 × 35 mm ² , each mirror element Is equivalent to irradiating an area of 28 μm square. In addition, as shown in FIG. 1, the DMD 128 used in this example has an overall reflecting surface that is substantially perpendicular to the optical axis AX of the projection optical system 120, so that each reflecting surface of each mirror element is in an ON state. Therefore, it is desirable to tilt at 0 ° parallel to the plane perpendicular to the optical axis AX and at 12 ° or −12 ° with respect to the plane perpendicular to the optical axis AX in the off state. At this time, in FIG. 1, the illumination light IL reflected by the on-state mirror element in the DMD 128 is reflected in the first direction, passes through the opening 129a of the light shield 129, and corresponds to the illumination area of the reticle 119. Illuminate the part. On the other hand, the illumination light IL reflected by the off-state mirror element in the DMD 128 is reflected in the second direction, is shielded by the light shield 129, and is not irradiated to the reticle 119. When a switching command is supplied from the main control system 125 to the DMD driving device 131, the DMD driving device 131 switches each mirror element in the DMD 128 on and off.

  Next, the exposure amount control operation of this example will be specifically described. As shown in the exposure amount map of FIG. 2, the pattern area PA of the reticle 119 is formed with several types (three types in FIG. 2) of circuits having different functions and different pattern characteristics, divided into partial areas PT1, PT2, and PT3. It is assumed that the appropriate exposure amount for each partial area is set to Dose1, Dose2, and Dose3. The appropriate exposure amount corresponds to the appropriate exposure amount Pi of each partial region PTi described above. The exposure times for the partial regions PT1 to PT3 for obtaining the appropriate exposure amounts are obtained by dividing the appropriate exposure amounts Dose1 to Dose3 by the exposure energy E per unit time, respectively. Here, it is assumed that the appropriate exposure amount has the following relationship.

Dose1 <Dose2 <Dose3 (2)
At this time, the largest dose 3 is used as the appropriate exposure amount for determining the upper limit of the exposure time when the wafer 121 is exposed through the reticle 119 of FIG. That is, the exposure time t3 corresponding to Dose3 is supplied from the main control system 125 to the timer control system 106 in advance, and the shutter 104 is closed when the elapsed time from the start of exposure of each shot area reaches t3.

  FIG. 3 shows partial regions MD1, MD2, and MD3 on the DMD 128 corresponding to the partial regions PT1 to PT3 of the reticle 119 of FIG. Note that the arrangement shown in FIG. 3 is reversed from the arrangement shown in FIG. 2 by the imaging optical system including the condenser lenses 127 and 118 shown in FIG. In the description of this example, for the sake of simplification, the description will be divided into three partial areas. However, the present invention is not limited to this. In principle, the illumination area is limited to the number of mirror elements constituting the DMD 128. Can be divided.

  Next, the operation of the DMD 128 in FIG. 1 will be described. Prior to exposure, all mirror elements of the DMD 128 are in an on state (no tilt), and the reflected light can irradiate all pattern areas (assuming that they match the illumination area) of the reticle 119. . Temporarily, an area on the wafer 121 that is not desired to be exposed generally corresponds to a light-shielding pattern on the reticle 119. Therefore, it is not necessary to consider an area where the appropriate exposure amount is zero. However, when the correction exposure is performed on the shot area on the wafer once exposed, there may be an area where the appropriate exposure amount is set to zero. In such a case, the mirror element corresponding to the region can be turned off (with tilt) from the beginning. In addition, when it is desired to expose a part of the shot area under different exposure conditions (polarization characteristics of exposure light, illumination NA, etc.) from the other areas, a mirror element corresponding to the part of the area is used. After exposure in an off state (with tilt), exposure may be performed with only the mirror elements corresponding to a part of the region turned on (no tilt) by changing the exposure conditions.

  When the shutter 104 is opened and exposure is started, the main control system 125 integrates the value of the exposure energy ΔE per unit time sent to the main control system 125 by the illuminance calculation system 112, and the wafer 121 is passed through the reticle 119. The integrated exposure amount irradiated to the is measured in real time. First, when the integrated exposure amount reaches the smallest optimum exposure amount Dose1, all the mirror elements in the corresponding partial area MD1 of the DMD 128 in FIG. 3 are turned off. At this time, since the mirror surface is inclined, the reflected light from the mirror element in the off state is not guided to the condenser lens 118 of FIG. Therefore, the partial area PT1 of the pattern area PA of the reticle 119 in FIG. 2 is not illuminated, and the local area in the shot area on the wafer 121 corresponding to this part is not irradiated with the illumination light IL thereafter. That is, the partial region PT1 is controlled to the appropriate exposure amount Dose1. Subsequently, when the integrated exposure amount reaches the appropriate exposure amount Dose2, all mirror elements in the partial region MD2 of the DMD 128 are turned off, and the local region in the shot region on the wafer 121 corresponding to the partial region PT2 of the reticle 119 Thereafter, the illumination light IL is not irradiated. That is, the partial region PT2 is controlled to the appropriate exposure amount Dose2. When the integrated exposure amount reaches the appropriate exposure amount Dose3, since the shutter 104 is closed, the local region in the shot region on the wafer 121 corresponding to the partial region PT3 of the reticle 119 is irradiated with the illumination light IL thereafter. The partial area PT3 is controlled to the appropriate exposure amount Dose3. As a result, the entire surface of the shot area on the wafer 121 is exposed with an appropriate exposure amount. At this time, all mirror elements in the partial area MD3 of the DMD 128 are turned off based on the integrated value of the exposure energy ΔE per unit time, and the local area in the shot area on the wafer 121 corresponding to the partial area PT3 of the reticle 119 is set. Even if the region is not irradiated with the illumination light IL, there is no problem.

  As described above, according to the present embodiment, when the pattern of the reticle 119 having locally different pattern characteristics is exposed on the wafer 121 as in, for example, a system LSI, the optimum integration is performed for each local region. The exposure time of the illumination light IL is controlled for each local region using the DMD 128 so that the exposure is performed with the exposure amount. Therefore, the pattern image can be transferred with the optimum integrated exposure amount over the entire shot area on the wafer 121, and the line width uniformity of the pattern image is improved.

  Note that not only the components set in accordance with the pattern characteristics as described above, but also components for correcting the illuminance uniformity of the illumination light IL by the illumination optical system are included in the optimal exposure amount setting value set in advance. Alternatively, a component (correction map) resulting from the resist process may be superimposed. That is, the illumination light IL is desired to have a uniform illuminance over the entire exposure area on the wafer, but it may not always have a uniform illuminance distribution.

  For example, FIG. 4A shows an example of the illuminance distribution of the exposure region 135 on the wafer. In FIG. 4A, the peripheral region of the exposure region 135 has a lower illuminance than others. In order to correct this, as shown in FIG. 4B, a correction map is set in the illumination area 135M of the reticle to set a larger exposure amount in the peripheral area than in the other areas. That is, the correction map of FIG. 4B is a correction value of the illuminance (exposure amount per unit time) that makes the illuminance uniform over the entire exposure area 135 when added to the illuminance distribution of FIG. It is a map. By adjusting the exposure time for each partial area by each mirror element of DMD 128 in FIG. 1 corresponding to the correction value, exposure is performed with a more appropriate integrated exposure amount distribution for each partial area in exposure area 135 on the wafer. It can be performed.

On the other hand, correction components resulting from the resist process are generally distributed concentrically from the center of the wafer 121 as shown in FIG. In FIG. 5A, a darker portion indicates that more exposure is required. For example, a correction map on the reticle focusing on the shot area F in the wafer 121 is shown in FIG. 5B, and a correction map as shown in FIG. 5B is set for each shot area in the wafer 121. . If the reticle pattern shown in FIG. 2 is exposed, an exposure map obtained by adding the correction exposure determined by the correction maps of FIGS. 4B and 5B to the exposure map of FIG. Based on the above, the DMD 128 may be controlled to perform exposure in the same manner as in the above embodiment.
Needless to say, the correction map can be determined in the same manner even when the exposure amount component to be corrected due to the resist process is distributed in an elliptical shape with respect to the center of the wafer 121.

  In this way, exposure is performed by forming a map of the optimum exposure amount for each shot area, but the optimum exposure amount is set in a range of about 70% to 100% if the maximum exposure amount is 100%. It is expected to become. In such a case, exposure may be performed in the shortest time, and the amount of light applied to the DMD 128 may be adjusted within the exposure time of one shot in order to perform exposure with each optimum exposure amount with high accuracy. That is, as shown in FIG. 6A, until the integrated exposure amount ΣE for the wafer reaches the minimum value Dose1 (70% of the maximum value in FIG. 6A) of the optimum exposure amount, it is shown in FIG. Thus, the illuminance (unit area, energy per unit time) IU is increased to reach 70% in a short time. 6A and 6B is the time ts from the start of exposure. For this purpose, the output of the mercury lamp 101 in FIG. 1 is increased, or the amount of light reduction by a light amount adjustment mechanism (not shown) disposed between the mercury lamp 101 and the fly-eye lens 108 is reduced, for example. Good. When the optimum exposure amount in FIG. 6 (a) is between 70% and 100% of the maximum value, the illuminance IU is reduced as shown in FIG. 6 (b), and each mirror element is turned on / off. What is necessary is just to be able to control time accurately.

  In this example, the main control system 125 turns off each mirror element from the on state via the DMD driving device 131 based on the integrated value of the exposure energy ΔE per unit time supplied from the illuminance calculation system 112. Although the timing for switching to the state is controlled, the output from the illuminance calculation system 112 is not used, but within the shot area corresponding to the partial areas PT1, PT2, PT3 on the reticle 119 based on the above equation (1). The exposure times t1, t2, and t3 for each local region are obtained, and the mirror elements in the partial regions MD1, MD2, and MD3 when the elapsed time from the exposure start time reaches the exposure times t1, t2, and t3 in sequence. May be sequentially switched from the on state to the off state.

In the case where the light source is a pulse light source such as an excimer laser, the same effect can be obtained by replacing the energy per unit time described above (for example, the illuminance IU in FIG. 6B) with the energy per pulse. .
When the energy of each pulse emitted from the pulsed light source is substantially constant, the target irradiation pulse number N1 for each local region in the shot region corresponding to the partial regions PT1, PT2, PT3 of the reticle 119 in FIG. , N2, N3 are determined, and the mirrors in the partial areas MD1, MD2, MD3 in FIG. 3 are reached when the count value of the number of irradiation pulses from the exposure start point reaches the target irradiation pulse numbers N1, N2, N3 sequentially. The elements may be sequentially switched from the on state to the off state.

Also, in this example, it has been described that each mirror element of the DMD 128 is switched on / off during one shot exposure as described above. However, each mirror element is alternately turned on / off at high speed during one shot exposure. In so doing, so-called duty control for adjusting the number of times of ON may be performed. The exposure amount control of this example is also effective in an exposure apparatus that uses an X-ray source as a light source.
In this example, the illumination blind 114 is used to define the shape and size of the illumination area on the reticle 119. However, the shape and size of the illumination area on the reticle 119 are also defined using the DMD 128. May be.
Further, in this example, a correction map is created in order to correct a change in pattern line width caused by unevenness of illumination light IL, unevenness of application of resist, unevenness of development, and the like. When there are few, it is not necessary to create a correction map. Further, without creating a correction map, only an exposure amount map that takes into account pattern characteristics, unevenness of illumination light IL, uneven application of resist, unevenness of development, and the like may be generated.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. In this example, the present invention is applied to the case where exposure is performed by a scanning exposure type projection exposure apparatus (scanning type exposure apparatus) comprising a scanning stepper.
FIG. 7 shows a schematic configuration of the scanning exposure apparatus 10 of this example. In FIG. 7, this scanning exposure apparatus 10 uses an excimer laser light source 16 as a pulsed light source as an exposure light source. This is a scanning projection exposure apparatus. The scanning exposure apparatus 10 includes an illumination system 12 including an excimer laser light source 16, a reticle stage RST that holds a reticle R illuminated by illumination light IL from the illumination system 12, and illumination light IL emitted from the reticle R as a wafer. A projection optical system PL that projects onto W, an XY stage 14 on which a Z tilt stage 58 that holds the wafer W is mounted, a control system thereof, and the like are provided.

  The illumination system 12 includes an excimer laser light source 16, a beam shaping optical system 18, an energy coarse adjuster 20, a fly-eye lens 22, an illumination system aperture stop plate 24, a beam splitter 26, a first relay lens 28, a reticle blind 30, The second relay lens 29, the beam splitter 13, the condenser lens 37, the reflection mirror 11 provided with a digital micromirror device, the light shielding body 55 as a diaphragm member, and the condenser lens 32 are included.

Each part of the configuration of the illumination system 12 will be described. As the excimer laser light source 16, a KrF excimer laser light source (oscillation wavelength 248 nm), an ArF excimer laser light source (oscillation wavelength 193 nm), or the like is used. Instead of the excimer laser light source 16, a pulsed light source such as a metal vapor laser light source or a harmonic generator of a YAG laser, or a continuous light source such as a mercury lamp may be used. The average value of energy per pulse of the excimer laser light source 16 is normally stabilized at a predetermined center energy E ₀ , but the average value of the energy is a predetermined variable range above and below the energy E ₀ (for example, ± (About 10%). The beam shaping optical system 18 shapes the cross-sectional shape of the laser beam LB pulsed from the excimer laser light source 16 so that it efficiently enters the fly-eye lens 22 provided behind the optical path of the laser beam LB. For example, a cylinder lens and a beam expander (both not shown). The energy coarse adjuster 20 is disposed on the optical path of the laser beam LB behind the beam shaping optical system 18, and here, a plurality (for example, 6) of different transmittances (= 1−attenuation rate) around the rotating plate. ND filters (two ND filters 36A and 36D are shown in FIG. 7), and the rotating plate 34 is rotated by a drive motor 38, whereby an incident laser beam LB is obtained. It is possible to switch the transmittance with respect to 100% in multiple steps in a geometric series. The drive motor 38 is controlled by the main controller 50. The fly-eye lens 22 is disposed on the optical path of the laser beam LB emitted from the energy coarse adjuster 20, and forms a large number of secondary light sources for illuminating the reticle R with a uniform illuminance distribution. Hereinafter, the pulse laser beam emitted from the secondary light source is referred to as illumination light IL.

  An illumination system aperture stop plate 24 made of a disk-like member is disposed in the vicinity of the exit surface of the fly-eye lens 22. The illumination system aperture stop plate 24 includes, for example, an aperture stop made of a normal circular aperture, an aperture stop made of a small circular aperture for reducing the σ value as a coherence factor, and a ring for annular illumination. A band-shaped aperture stop and a modified aperture stop (only two of these aperture stops are shown in FIG. 7) in which a plurality of openings are arranged eccentrically for the modified light source method are arranged. Yes. The illumination system aperture stop plate 24 is rotated by a drive device 40 such as a motor controlled by the main control device 50, whereby any aperture stop is selectively placed on the optical path of the illumination light IL. Set to A beam splitter 26 having a low reflectance and a high transmittance is disposed on the optical path of the illumination light IL emitted from the illumination system aperture stop plate 24. Further, a reticle blind 30 is interposed on the optical path behind the first beam blind 26. A relay optical system including a relay lens 28 and a second relay lens 29 is disposed.

  The reticle blind 30 includes a fixed blind and a variable blind. The fixed blind is disposed on a surface slightly defocused from the conjugate plane with respect to the pattern surface of the reticle R, and has a rectangular opening that defines an illumination area 42R on the reticle R. Is formed. Further, the variable blind in the reticle blind 30 forms an opening having a variable position and width in the scanning direction. Further, the opening has a leading edge and a trailing edge in the scanning direction at the start and end of scanning exposure, respectively. In response to this, the main controller 50 controls the position in the direction of the arrow in the figure via the drive unit 31 to prevent exposure of unnecessary portions on the reticle R.

  Further, an integrator sensor 46 including a condenser lens 44 and a photoelectric conversion element is disposed on a reflected light path by the beam splitter 26 in the illumination system 12. The illumination light IL reflected by the beam splitter 26 is received by the integrator sensor 46 via the condenser lens 44, and a photoelectric conversion signal of the integrator sensor 46 is converted into a peak hold circuit and an analog / digital converter (hereinafter, not shown). The output DS (digit / pulse) is supplied to the main controller 50 (arithmetic unit for calculating the integrated exposure amount) via the A / D converter. A correlation coefficient between the output DS of the integrator sensor 46 and the pulse energy (exposure amount) per unit area of the illumination light IL on the surface of the wafer W is obtained in advance and stored in the main controller 50. .

  After passing through the first relay lens 28, the illumination light IL that has passed through the rectangular opening of the reticle blind 30 passes through the second relay lens 29, is reflected by the beam splitter 13, and passes through the condenser lens 37 to be a reflection mirror. 11 is illuminated with a uniform illumination distribution. The reflected light from the reflecting mirror 11 passes again through the condenser lens 37, the beam splitter 13, the opening 55a of the light shielding body (which may be a light absorber) 55 as a diaphragm member, and the condenser lens 32, and the illumination area on the reticle R. Irradiate 42R uniformly. In addition, mirror elements (reflective elements) similar to the mirror elements of the digital micromirror device used in the first embodiment are arranged in a matrix in elongated regions at both ends corresponding to the scanning direction of the reticle R of the reflective mirror 11. The arranged mirror element portions D1 and D2 are arranged. A digital micromirror device (DMD) as a reflective element array is constituted by the mirror element portions D1 and D2 and the substrate on the back surface thereof. Each mirror element of the mirror element portions D1 and D2 is in the ON state in which the tilt angle of the reflecting surface is 0 ° (first reflection direction) and the other predetermined angle (first angle) as in the case of each mirror element of the DMD 128 in FIG. 2), the illumination light IL reflected when the mirror elements are in the on state passes through the opening 55a of the light blocking body 55, and the mirror elements are off. The illumination light IL reflected in the state is shielded by the light shield 55.

  At this time, the movable blind of the reticle blind 30, the reflection surface of the reflection mirror 11, and the pattern surface of the reticle R are disposed at optically conjugate positions. In some cases, it is better to have an exposure amount distribution gradient at the edge of the illumination area 42R in the scanning direction. For this case, the position of the fixed blind of the reticle blind 30 is slightly deviated from its conjugate position. It is placed at the focused position.

  Here, the projection optical system PL is composed of a plurality of lens elements arranged so as to have a telecentric optical arrangement on both sides. The projection magnification β of the projection optical system PL is a reduction magnification of, for example, 1/4 or 1/5. As described above, when the illumination area 42R on the reticle R is illuminated by the illumination light IL, an image (partially inverted) obtained by reducing the pattern in the irradiation area 42R formed on the reticle R with the projection magnification β by the projection optical system PL. Image) is formed in a slit-shaped exposure region 42W conjugate with the irradiation region 42R on the wafer W having a photoresist (photosensitive material) coated on the surface thereof. Hereinafter, the Z axis is taken in parallel to the optical axis of the projection optical system PL, the X axis is taken in a direction perpendicular to the paper surface of FIG. 7 in a plane perpendicular to the Z axis, and the Y axis is taken in a direction parallel to the paper surface of FIG. Take and explain. Here, the XY plane is almost a horizontal plane. A direction parallel to the Y axis (Y direction) is the scanning direction SD of the reticle R and the wafer W during scanning exposure, and a direction perpendicular to the X axis (X direction) is a non-scanning direction NSD perpendicular to the scanning direction. It is.

  The reticle R is sucked and held on the reticle stage RST. Reticle stage RST can be finely driven in the XY plane, and is scanned by reticle stage driving unit 48 in a scanning direction (Y direction) within a predetermined stroke range. The position of the reticle stage RST during the scanning is measured by an external laser interferometer 54R via a movable mirror 52R fixed on the reticle stage RST, and the measured value of the laser interferometer 54R is supplied to the main controller 50. Is done.

  The wafer W is sucked and held on the Z tilt stage 58 via a wafer holder (not shown), and the Z tilt stage 58 is mounted on the XY stage 14. The XY stage 14 is two-dimensionally driven on a wafer base (not shown) by a wafer stage driving unit 56 in the Y direction which is the scanning direction in the XY plane and in the X direction orthogonal thereto. The Z tilt stage 58 has a function of adjusting the position (focus position) in the Z direction on the wafer W and adjusting the tilt angle of the wafer W with respect to the XY plane. Further, the position of the XY stage 14 (wafer W) is measured by an external laser interferometer 54W (position detection device) via a movable mirror 52W fixed on the Z tilt stage 58, and the measurement of the laser interferometer 54W is performed. The value is supplied to the main controller 50.

  In addition, an illuminance unevenness sensor 59 composed of a photoelectric conversion element is provided in the vicinity of the wafer W on the Z tilt stage 58, and the light receiving surface of the illuminance unevenness sensor 59 is set to the same height as the surface of the wafer W. A detection signal of the illuminance unevenness sensor 59 is supplied to a main controller 50 functioning as an exposure controller via a peak hold circuit and an A / D converter (not shown). The main controller 50 includes a computer, and controls, for example, synchronous scanning of the reticle R and the wafer W, stepping of the wafer W, exposure timing, and the like so that the exposure operation can be performed accurately. In the present embodiment, the main controller 50 also performs exposure amount control during scanning exposure described later.

Specifically, the main controller 50, for example, at the time of scanning exposure, in synchronism with the reticle R is scanned at a speed V _R in via the reticle stage RST + Y direction (or the -Y direction), the XY stage 14 Then, the laser interferometers 54R and 54W are scanned so that the wafer W is scanned at a speed β · V _R (β is a projection magnification from the reticle R to the wafer W) in the −Y direction (or + Y direction) with respect to the exposure area 42W. Based on the measured value, the position and speed of reticle stage RST and XY stage 14 are controlled via reticle stage drive unit 48 and wafer stage drive unit 56, respectively. Further, at the time of stepping, main controller 50 controls the position of XY stage 14 via wafer stage drive unit 56 based on the measurement value of laser interferometer 54W.

  Further, the main controller 50 controls the light emission power of the excimer laser light source 16 by supplying the control information TS to the excimer laser light source 16. The main control device 50 controls the energy coarse adjuster 20 and the illumination system aperture stop plate 24 via the motor 38 and the drive device 40, respectively, and further via the drive device 31 in synchronization with the operation information of the stage system. The opening / closing operation of the movable blind in the reticle blind 30 is controlled. Thus, in this example, the main controller 50 also functions as an exposure controller and a stage controller. Of course, these controllers may be provided separately from the main controller 50. The main controller 50 is connected to a storage device 51 and an input / output device 62 such as a console. Similar to the first embodiment, the storage device 51 stores information on an exposure amount map and a correction map indicating an appropriate exposure amount for each partial region of the reticle R.

  Here, the reflection mirror 11 which is a feature of this example will be described. The reflection mirror 11 includes a portion where a dielectric multilayer film or an aluminum thin film is formed on a surface (reflection surface) having a high flatness of the substrate in order to reflect the illumination light IL satisfactorily and the surface along the surface. As described above, two mirror element portions D1 and D2 in which a plurality of mirror elements of a digital micromirror device (DMD) are arranged are provided. The individual mirror elements of the mirror element portions D1 and D2 are driven by the main controller 50 via the DMD driving device 33.

Although mirror elements similar to the mirror element portions D1 and D2 may be arranged on the entire reflecting surface of the reflecting mirror 11, the entire area does not necessarily need to be a mirror element in order to control the exposure amount. Further, instead of the mirror element portions D1 and D2, one mirror element portion may be provided, or three or more mirror element portions may be provided.
FIG. 8 shows a conjugate relationship between the reflecting mirror 11 and the illumination area 42R on the reticle R. In FIG. 8, the reflecting mirror 11 is a perspective view from the back surface of the reflecting surface. In addition, each point of the reflecting mirror 11 and a corresponding point (substantially conjugate point) of the illumination area 42R are inverted up and down and left and right, as schematically shown using a virtual character “F”, but 1: Corresponds to 1. As shown in FIG. 8, the mirror element portions D1 and D2 are arranged in a line along the non-scanning direction at both end positions in the scanning direction on the reflecting surface of the reflecting mirror 11, and the reflected light is an illumination region 42R of the reticle R. A position corresponding to the edge R1 or the edge R2 in the scanning direction is irradiated. The edges R1 and R2 are the front edge and the rear edge, respectively, if the scanning direction of the reticle R is the -Y direction, and the trailing edges if the scanning direction of the reticle R is the + Y direction (direction SD (+)). And the leading edge.

As shown in the perspective view of FIG. 9, the mirror element portions D1 and D2 are both n rows (d1 ₁ , d1 ₂ ,. _n , and d2 ₁ , d2 ₂ ,..., d2 _n ) and n × m in a matrix of m columns in the non-scanning direction (X direction). It is assumed that a mirror element is arranged. n and m are arbitrary integers of 1 or more.
At this time, the number (n) of mirror elements in the scanning direction does not have to be a number that can irradiate the entire scanning direction of the illumination region 42R, but the number (m) of mirror elements in the non-scanning direction is the illumination region. It is desirable to set the number so that irradiation is possible over the entire area of 42R in the non-scanning direction.

  Here, in FIG. 8, for example, the mirror element of the portion A in the mirror element portion D1 (corresponding to a plurality of adjacent mirror elements in FIG. 8) is turned off (tilted) by the DMD driving device 33 of FIG. If this is the case, the light reflected from the mirror element in the portion A (shown by the alternate long and short dash line) is a light shield (or may be an absorber) 55 disposed at the pupil position of the illumination system between the condenser lens 37 and the condenser lens 32. The illumination light is not incident on the conjugate position A ′ on the reticle R. If the mirror element of the portion A is turned off between the times ta and tb during scanning exposure, the exposure amount of the region B on the reticle is reduced compared to other regions. Of course, the exposure amount of the area on the wafer W corresponding to the area B also decreases. This is because the width in the scanning direction of this portion of the exposure region is substantially reduced. The larger the number (number of rows) of mirror elements that are turned off along the scanning direction, the larger the amount of exposure that is reduced. In order to accurately separate the region on the reticle R or on the wafer W where the amount of light is to be reduced from the region that is not so, the reflecting mirror 11 needs to be disposed at a position optically conjugate with the reticle R. However, in order to prevent a mechanical gap between adjacent mirror elements from being projected as a dark line, the reflection mirror 11 may be slightly shifted from the conjugate position.

Further, in the storage device 51 of FIG. 7, an exposure amount map in the shot area is stored in advance for each reticle to be used by the operator via the input / output device 62.
FIG. 10 shows an example of an exposure map in the pattern area PA of the reticle R. In FIG. 10, several types of functional circuits are formed in the partial areas PT1, PT2, PT3 in the pattern area PA. Are set to Dose1, Dose2, and Dose3 (assuming Dose1>Dose2> Dose3). This exposure amount is data obtained based on the measurement result of the line width distribution of the transfer image of the isolated pattern among the transfer images obtained by transferring the pattern of the reticle R to a plurality of shot areas on the wafer W in advance. It is desirable that the data be uniform data for the pattern line widths of the plurality of shot areas (first step). An isolated pattern (for example, an isolated line or contact hole pattern) is more sensitive to exposure than a dense pattern. Therefore, it is obtained based on the measurement result of the line width distribution of the transferred image of the isolated pattern. By using the exposure amount that equalizes the pattern line width of each shot area to the desired line width as data, more accurate exposure amount control can be realized, and the pattern line width accuracy can be further improved. Can do. The exposure amount in the same shot determined in this way is expected to be set in a range where the average exposure amount is increased or decreased by several percent to 10%.

  Hereinafter, the steps of scanning and exposing the photoresist on the wafer W in FIG. 7 using the reticle R having the pattern shown in FIG. 10 will be described in order. Here, in the scanning exposure in which all the mirror elements of the mirror element portions D1 and D2 of the reflection mirror 11 are in the on state (the entire illumination area 42R is irradiated with the illumination light IL), the exposure amount irradiated to the photoresist The intensity of the illumination light IL is selected by performing at least one of the selection of the ND filter of the energy coarse adjuster 20 and the adjustment of the light emission power of the excimer laser light source 16 so that Dose1 is the largest appropriate exposure amount in the pattern region. Is adjusted.

Further, in FIG. 11 showing the reticle R in the scanning, at time t _0, the illumination area 42R is assumed to be the positional relationship shown in position B1. In an actual scanning exposure apparatus, the illumination area 42R is stationary and the reticle R is scanned as the reticle stage moves. In FIG. 11, the illumination area 42R is moved for convenience, and the pattern of the reticle R is moved. The positional relationship with the area PA is shown. At this time, one movable blind of the reticle blind 30 in FIG. 7 corresponding to the rear edge of the scanning direction SD (−) is closed, and the outer periphery of the pattern area PA (that is, the corresponding shot area SA on the wafer W). The area is not exposed. When the movable blind that has been closed in synchronization with the start of scanning is opened, the partial area PT1 is first exposed, and when the illumination area 42R is completely in the pattern area PA, the movable blind is fully open. Scanning exposure in this state is performed until time t ₁ when the front edge portion 42RF of the illumination region 42R reaches the end (position B2) of the partial region PT1.

At the time t ₁ when the front edge of the illumination area 42R reaches the partial area PT2, as shown in FIG. 12, the mirror elements in the P rows of d1 ₁ to d1 _p of _one mirror element portion D1 of the reflecting mirror 11 are sequentially arranged. Then, the entire area (all m columns) in the non-scanning direction is turned off (with tilt) so that the reflected light from the P rows of mirror elements is not projected onto the partial area PT2 in FIG. In FIG. 12 (the same applies to FIGS. 13 and 14), the mirror element Md in the off state is shaded. In FIG. 12, the number P of mirror element rows to be turned off is determined so that the integrated exposure amount of the partial region PT2 is Dose2. Specifically, as described above, the exposure amount is set to Dose1 when all the mirror elements are in the ON state. Therefore, if the width in the scanning direction of the illumination region 42R at this time is L, For example, the width in the scanning direction may be L × (Dose2 / Dose1). Therefore, the width of the mirror element with the number of rows P is determined to be L × (1−Dose2 / Dose1). In FIG. 11, when the rear edge of the illumination area 42R reaches the boundary between the partial areas PT1 and PT2, the exposure of the partial area PT1 is completed, and the partial area PT1 is exposed with Dose1.

Thereafter, until the time t ₂ when the front edge of the illumination area 42R (more precisely, the area exposed by the reflected light from the mirror element in the d1 _{p + 1-th} row) reaches the partial area PT3 (position B3). The exposure is performed with the mirror elements in the P rows of d1 ₁ to d1 _{p in} the element portion D1 being off. At time t _2, the as shown in FIG. 13, _d1 p + 1 ~d1 _Q row of mirror elements are sequentially turned off in 1~r column in the mirror element D1. These 1 to r columns correspond to the number of mirror elements that irradiate the width X3 in the non-scanning direction of the partial region PT3 in FIG. The width of the mirror element of the number Q of rows is determined to be L × (1−Dose3 / Dose1) as described above. In this way, although mean that the scanning exposure until time t ₃ when the trailing edge of the illumination area 42R in Fig. 11 reaches the end of the pattern area PA are performed, the scanning start time as well as the pattern area PA (i.e., wafer One movable blind of the reticle blind 30 corresponding to the front edge in the scanning direction is closed in synchronization with scanning so that the outer peripheral area of the shot area SA) on W is not exposed.

In the above description, the case where the exposure amount of the pattern region to be scanned decreases as the scanning exposure progresses has been described as an example. However, there may be a case where Dose3> Dose2. In such a case, at time t ₂ in FIG. 11, of the mirror element was turned off until then, d1 _ps ~ D1 _p rows of mirror elements 1~r column of Figure 14 are sequentially turned on You can do so. The width of the mirror element with the number of rows PS is determined to be L × (1−Dose3 / Dose1) as described above. Alternatively, a part of the mirror element portion D2 disposed at the rear edge portion of the illumination region 42R is turned off in advance, and the mirror element portion D2 when the rear edge portion reaches the boundary portion between the partial regions PT2 and PT3. The columns that irradiate the partial region PT3 may be turned on with a necessary number of rows.

  Through the above steps, exposure of one shot region on the wafer W is completed, and exposure is performed with an optimum exposure amount for each partial region on the reticle R (second step). In a scanning exposure apparatus, when performing exposure of the next shot area, it is general to perform scanning exposure in a direction opposite to the scanning direction of the immediately preceding shot area. In this case, the mirror element portion D1 described above may be operated by replacing it with the mirror element portion D2 corresponding to the front edge portion in the scanning direction.

In addition, the storage device 51 of FIG. 7 includes a correction for offsetting the fluctuation component of the line width caused by the device manufacturing process such as non-uniformity of the coating thickness of the photosensitive material on the wafer and non-uniformity during development. The exposure amount is stored as a correction map for each position on the wafer.
As shown in FIG. 15A, this corrected exposure amount is generally distributed concentrically (or elliptically) from the center of the wafer W. FIG. 15A shows that a larger amount of exposure is required in proportion to the distance from the center, but it is a first-order, second-order, or higher-order function of the distance from the center. In some cases. For example, the operator may input a function of distance from the center to the input device 62 in FIG. 7 so that a correction map is set in the storage device 51 for each position of each shot area SA. For example, the correction map of the shot area SA whose center coordinates are (x, y) is calculated from the input function and the shape of the shot area SA and is generated as shown in FIG.

Similar to the operation described with reference to FIGS. 11 to 14, the mirror element portion D1 of the reflecting mirror 11 of FIG. 7 is arranged according to the correction map of FIG. 15B in the positional relationship between the illumination area 42R and the shot area SA. Or if the mirror element of D2 is driven, it can expose with the exposure amount for compensating the error of the line width resulting from a device manufacturing process.
7 also stores data for correcting the illuminance uniformity in the non-scanning direction caused by the exposure apparatus (illumination system 12). The light amount distribution of the shot area SA on the wafer is desired to be uniform within the exposure area, but it is not necessarily uniform.

  For example, as shown in FIG. 16A, it is assumed that the illuminance distribution in the exposure area IA on the shot area SA of the wafer is strong in the central portion and the illuminance IIL decreases toward the periphery. At this time, the integrated exposure amount ΣE on the wafer by the scanning exposure has a distribution as shown in FIG. 16B in which the illuminance in the scanning direction SD is integrated for each point in the non-scanning direction NSD. That is, the integrated exposure amount distribution in the scanning direction SD is flattened by scanning, but the non-uniformity of the integrated exposure amount distribution in the non-scanning direction NSD is not eliminated. As a method for solving this, as shown in FIG. 17A, the width in the scanning direction SD of the exposure area IA on the shot area SA of the wafer is adjusted for each position in the non-scanning direction NSD, and the integrated exposure amount ΣE is shown in FIG. What is necessary is just to make it uniform like 17 (b). The illumination unevenness correction map is obtained by using the width in the scanning direction of the shot area for each position in the non-scanning direction NSD, and the illumination unevenness correction map is also stored in the storage device 51 of FIG.

  In this case, one of the mirror elements D1 or D2 of the reflecting mirror 11 of FIG. 7 or D2 (or both of them may be used) is switched on / off, and the shape of the illumination area 42R is as shown in FIG. What is necessary is just to make it become the same shape as the exposure area | region IA. It is known that the illuminance uniformity of the exposure apparatus changes over time depending on the exposure conditions, and in the method of this example, the shape of the illumination area 42R can be arbitrarily changed. Can be corrected.

In this example, as described above, the exposure operation corresponding to the three typical types of data stored in the storage device 51 of FIG. 7 has been described independently. However, each data was used in combination. Correction (overlapping correction) is also possible. Further, the exposure amount control for each shot area may be performed without using the correction map as described above.
In the above embodiment, as shown in FIG. 7, the case where the reflecting mirror 11 has the two mirror element portions D1 and D2 has been described, but the mirror element portion may be provided only on one side. Further, in the scanning exposure apparatus, a technique may be used in which the illuminance distribution of the front edge portion and the rear edge portion of the illumination area 42R is intentionally inclined to improve the accuracy of exposure amount uniformity. In such a case, as shown in FIG. 18, the mirror element part D3 may be arranged at the center of the reflection mirror 11 in the scanning direction.

  18 shows a modification of the scanning exposure apparatus of FIG. 7. In FIG. 18, in which parts corresponding to those of FIG. 7 are given the same reference numerals, the illumination light IL that has passed through the rectangular opening of the reticle blind 30 is shown. Passes through the second relay lens 29 and illuminates the reflection mirror 11 disposed at an inclination of 45 ° with respect to the optical axis through the condenser lens 49 with a uniform illumination distribution. The downward reflected light from the reflecting mirror 11 passes through the condenser lens 42, the opening of the light shield 55, and the condenser lens 32, and uniformly illuminates the illumination area 42R on the reticle R. In addition, a mirror element portion D3 similar to the mirror element portion D1 of FIG. Each mirror element of the mirror element part D3 is in the ON state where the tilt angle of the reflecting surface is 0 ° (first reflection direction) and the other predetermined angle (second When the mirror elements are in the on state, the illumination light IL reflected when the mirror elements are in the on state passes through the opening of the light blocking body 55 and the mirror elements are in the off state. The illumination light IL reflected by the light is shielded by the light shield 55. The mirror element portion D3 is also controlled by the DMD driving device 33. The other configuration is the same as that of the scanning exposure apparatus of FIG.

In FIG. 18, it is not necessary to arrange all the reflection regions of the reflection mirror 11 at positions optically conjugate with the reticle R, and the center of the reflection mirror 11 where the mirror element portion D3 is located is conjugate with the pattern surface of the reticle R. As described above, since the reflecting mirror 11 may be arranged, there is an advantage that the arrangement of the optical system is simplified.
FIG. 19 shows a conjugate relationship between the reflection mirror 11 of the scanning exposure apparatus of FIG. 18 and the illumination region 42R on the reticle R. In FIG. 19, the mirror element portion D3 in the reflection mirror 11 is in contact with the reticle R. Since it is arranged centering on the conjugate position, the reflected light irradiates a position corresponding to the central portion in the scanning direction of the illumination region 42R on the reticle R. The mirror element portion D3 is n in a matrix of n rows in the scanning direction (each row is d3 ₁ , d3 ₂ ,..., D3 _n ) and m columns (each row is 1, 2,. It is assumed that xm mirror elements are arranged. Here, for example, the mirror element (corresponding to a plurality of adjacent mirror elements in FIG. 19) in the central portion C in the mirror element portion D3 is turned off (tilted) by the DMD driving device 33 in FIG. If so, the light reflected from the mirror element turned off (indicated by a dotted line) may be a light shield 55 (or an absorber) disposed at the optical pupil position between the condenser lens 42 and the condenser lens 32. ) 55, and is not irradiated with illumination light at the conjugate position C ′ on the reticle R.

If all the mirror elements are in the on state (not tilted) at the scanning exposure start time t ₀ and the mirror elements in the portion C are turned off between time ta and tb, The exposure amount in the area E is smaller than that in other areas. Naturally, the exposure amount of the area on the wafer W corresponding to the area E also decreases. This is because the width in the scanning direction of the exposure area 42W of this portion decreases, and the amount of exposure that decreases decreases as the number of mirror elements that are turned off increases in the scanning direction. In order to accurately separate the region on the reticle R or on the wafer W where the exposure amount is desired to be reduced and the region that is not so, it is necessary to dispose the reflecting mirror 11 at a position optically conjugate with the reticle R. However, in the configuration of FIG. 18 and FIG. 19, the mirror element portion D3 is disposed substantially at the conjugate position with the conjugate position as the center.

20A and 20B are graphs showing the distribution of the illuminance IIL of the illumination area 42R in the configuration of FIG. 18 with the scanning direction SD as the horizontal axis. The illuminance distribution when the mirror elements of the mirror element portion D3 of the reflection mirror 11 are all in the on state is substantially flat as shown in FIG. On the other hand, in the illuminance distribution in which all the mirror elements of the mirror element portion D3 are in the OFF state, the illuminance IIL near the center is 0 as shown in FIG. 20B, but the edge portions (front edge portion or The inclination of the illuminance distribution at the trailing edge is maintained. Since the integrated exposure amount for each point of the photoresist on the wafer W corresponds to the area (integrated value) of the illuminance distribution graph of FIG. 20A or 20B by the scanning exposure, the mirror element portion D3. It can be easily understood that the integrated exposure amount decreases as the number of rows of the mirror elements turned off increases. Since the difference between the largest exposure amount to be irradiated and the smallest exposure amount in one shot area is considered to be about 10%, the mirror elements in all rows are turned on for normal exposure amount control. It is sufficient to provide the number of rows of mirror elements so that the area is reduced by 10% with respect to the area of the graph.
In the second embodiment described above, the mirror element portions D1, D2, and D3 are controlled based on the time during the scanning of the reticle R. However, the measurement value of the interferometer 54R (or the interferometer 54W) is used. The mirror element portions D1, D2, and D3 may be controlled based on the above.

As described above, according to this example, it is possible to perform exposure with an optimal exposure amount for each local area in the shot area in accordance with the characteristics of the pattern transferred in the shot area. In addition, it is possible to correct pattern line width errors caused by uneven application of photoresist and uneven development, and it is also possible to correct illuminance non-uniformity caused by an exposure apparatus (such as the illumination system 12).
In each of the embodiments described above, the case where the reduction system is used as the projection optical system has been described. However, the present invention is not limited to this, and the projection optical system may be an equal magnification or enlargement system. Either a system or a reflection system may be used.

  Further, for example, for a semiconductor device, a step of designing the function / performance of the device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and the projection exposure apparatus (exposure apparatus) of the above-described embodiment Thus, the wafer is manufactured through a step of transferring a reticle pattern to a wafer, a device assembly step (including a dicing process, a bonding process, and a package process), an inspection step, and the like.

  The present invention can also be applied to the case where exposure is performed with an immersion type exposure apparatus disclosed in, for example, International Publication No. 99/49504 pamphlet. The present invention can also be applied to an exposure apparatus that uses extreme ultraviolet light (EUV light) having a wavelength of about 1 to 100 nm as an exposure beam. An optical system using EUV light is a reflection type, but since the reflection element array of the present invention is a reflection type optical member, it can be used for EUV light as it is.

  Further, the present invention is not limited to an exposure apparatus for manufacturing a semiconductor device, but is used for manufacturing a display including a liquid crystal display element, a plasma display, and the like. An exposure apparatus for transferring a device pattern onto a glass plate and a thin film magnetic head. The present invention can also be applied to an exposure apparatus that transfers a device pattern used in the process onto a ceramic wafer, and an exposure apparatus that is used to manufacture an image sensor (CCD, etc.), an organic EL, a micromachine, a DNA chip, and the like. In addition to microdevices such as semiconductor elements, circuits for glass substrates or silicon wafers are used to manufacture masks used in optical exposure equipment, EUV exposure equipment, X-ray exposure equipment, and electron beam exposure equipment. The present invention can also be applied to an exposure apparatus that transfers a pattern.

In the above-described embodiment, the light transmissive mask in which a predetermined light shielding pattern (or phase pattern / dimming pattern) is formed on a light transmissive substrate is used, but instead of these masks, for example, As disclosed in US Pat. No. 6,778,257, an electronic mask that forms a transmission pattern or a reflection pattern based on electronic data of a pattern to be exposed may be used.
In addition, this invention is not limited to the above-mentioned embodiment, Of course, a various structure can be taken in the range which does not deviate from the summary of this invention. In addition, the entire disclosure of Japanese Patent Application No. 2005-035343 filed on February 14, 2005, including the specification, claims, drawings, and abstract, is incorporated herein by reference in its entirety. Yes.

  According to the present invention, since it is possible to perform exposure with an optimum exposure amount for each of a plurality of local regions, it is possible to improve the line width uniformity of an image of a pattern exposed on an object. Therefore, a device in which a plurality of circuits are integrated into one chip can be manufactured with high accuracy and high yield.

Claims (18)

In an exposure apparatus that exposes an object with an exposure beam from a light source,
A plurality of reflecting elements each capable of controlling the reflection direction of the exposure beam, the reflecting element disposed between the light source and the object for adjusting an illuminance distribution in an illumination area of the exposure beam on the object An array,
A storage device storing exposure amount control data for controlling the exposure amount of the object;
An exposure apparatus comprising: a control device that controls the reflective element array based on the exposure amount control data stored in the storage device.   The exposure apparatus according to claim 1, wherein the reflection element array includes a digital micromirror device. Each reflecting element constituting the reflecting element array reflects the exposure beam in one of the first and second reflecting directions,
A beam splitter for guiding the exposure beam from the light source to the reflective element array;
The exposure apparatus according to claim 1, further comprising a diaphragm member that blocks the exposure beam reflected in the second reflection direction.   4. The exposure apparatus according to claim 1, wherein the exposure amount control data is set so that a line width distribution of a pattern image formed on the object has a predetermined distribution. 5. . The object is a substrate coated with a photoreceptor;
2. The exposure amount control data is set so as to correct at least one of a non-uniformity of a coating thickness of the photosensitive member and a non-uniformity of development characteristics depending on a position on the substrate. 5. The exposure apparatus according to any one of 4 above.   The reflective element array is disposed at a position substantially conjugate with the object between the light source and the object, or at a position shifted from the substantially conjugate position by a predetermined amount. Item 6. The exposure apparatus according to any one of Items 1 to 5. An arithmetic unit for obtaining an integrated exposure amount of the exposure beam for the object during the exposure of the object;
The exposure according to claim 1, wherein the control device controls the reflective element array based on an integrated exposure amount obtained by the arithmetic device and the exposure amount control data. apparatus.   The exposure apparatus according to claim 1, wherein the exposure apparatus is a scanning exposure type that moves the object relative to the exposure beam during exposure of the object. A position detecting device for measuring position information of the object in the scanning direction;
The exposure apparatus according to claim 8, wherein the control apparatus controls the reflective element array based on position information obtained by the position detection apparatus and the exposure amount control data.   The exposure amount control data is set so that a light amount integrated value in a scanning direction of an illumination area of the exposure beam is substantially uniform in a non-scanning direction orthogonal to the scanning direction. Item 10. The exposure apparatus according to Item 8 or 9.   9. The reflection element array includes a plurality of reflection elements arranged in one or a plurality of lines in a region corresponding to a predetermined position in the scanning direction of the illumination region of the exposure beam. The exposure apparatus according to any one of 10.   The exposure apparatus according to any one of claims 8 to 11, wherein the control device controls the width of the illumination region of the exposure beam in the scanning direction by controlling the reflective element array.   The exposure apparatus according to claim 1, wherein the exposure amount control data is set for each of a plurality of partitioned areas on the object.   The said control apparatus changes the illumination intensity distribution in the said illumination area based on the said exposure amount control data during the exposure of one division area on the said object. The exposure apparatus according to one item.   15. The object is exposed by illuminating a mask on which a predetermined pattern is formed with an exposure beam from the reflection element array, and projecting an image of the pattern of the mask onto the object. The exposure apparatus according to one item.   The exposure apparatus according to claim 15, further comprising an optical integrator that is disposed between the light source and the mask and causes an exposure beam from the light source to be incident on the reflective element array with a uniform illuminance distribution. In an exposure method of exposing an object by irradiating the object with an exposure beam from a light source,
A first step of obtaining exposure amount control data for controlling at least one of an exposure amount and an exposure amount distribution for each of a plurality of partitioned regions on the object;
Using a reflective element array that is disposed between the light source and the object and includes a plurality of reflective elements each capable of controlling the reflection direction of the exposure beam,
And a second step of controlling an illuminance distribution in an illumination area of the exposure beam on the object based on the exposure amount control data.   A device manufacturing method using the exposure apparatus according to any one of claims 1 to 16.

Images