JP2000205946A - Light intensity measuring device, image sensor, aerial image measuring device and exposure device - Google Patents

Abstract

(57) [Problem] To provide a light intensity measuring element, an image sensor, an aerial image measuring apparatus, and an exposure apparatus capable of accurately and quickly measuring the intensity of incident light in a far ultraviolet region. A conductive material is interposed between a pair of electrodes.
Are interposed to form the light intensity measuring element 25. The image sensor 24 is configured by arranging a plurality of light intensity measuring elements 25 so as to be continuous. The conductive material 31 is made of indium tin oxide (ITO), antimony tin oxide (AT
O) or the like, and is made to dissipate from between the electrodes 29 and 30 by receiving the exposure light. The intensity of the exposure light is detected based on the changed electric resistance characteristic of the conductive material 31, and the incident aerial image is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light intensity measuring element for measuring the intensity of incident light, and an image pickup device provided with the light intensity measuring element for detecting an incident aerial image. A spatial image measuring device for measuring the spatial image of the pattern projected via the projection optical system, and the spatial image measuring device for measuring the spatial image of the pattern projected via the projection optical system; The present invention relates to an exposure apparatus that performs projection transfer on a substrate.

[0002]

2. Description of the Related Art For example, in a photolithography process in a manufacturing process of a micro device such as a semiconductor device, a liquid crystal display device, a thin film magnetic head, an imaging device, etc., a pattern formed on a mask by an exposure apparatus passes through a projection optical system. And is projected and transferred onto a substrate coated with a photosensitive material. Among exposure apparatuses of this type, especially in an exposure apparatus for manufacturing a semiconductor element, the exposure light has been further shortened in wavelength in order to cope with recent miniaturization of circuit patterns. In such a flow, as exposure light, ultraviolet light having a relatively short wavelength, for example, KrF excimer laser light (wavelength:
248 nm) has also been developed. Further, as exposure light, far ultraviolet light having a shorter wavelength, for example, A
rF excimer laser light (wavelength: 193nm), F ₂ excimer laser light (wavelength: 157 nm) exposure apparatus using have also been developed.

In this type of exposure apparatus, when measuring the aerial image of a projected pattern, for example, the following measuring method is employed. That is, in the first conventional method, first, a spatial image of a pattern is actually projected and transferred onto a wafer, and the printed spatial image is developed. The developed aerial image is observed using a scanning electron microscope (SEM) or the like, and the line width and rise of the aerial image are measured, and the light intensity of the exposure light reaching the image plane of the projection optical system is measured. Etc. are measured.

In the second conventional method, an aerial image of a projected pattern is enlarged via an enlargement optical system, and a CCD image is enlarged.
(Charge Coupled Device). The light intensity and the like of the exposure light reaching the image plane of the projection optical system are measured by image analysis of the received aerial image.

[0005]

However, in the first conventional method, it is necessary to develop the aerial image printed on the substrate, so that the aerial image cannot be measured in real time. there were. In particular, as described above, observing a developed aerial image using an SEM involves cumbersome operations such as metal deposition on the surface to be observed and evacuation in the SEM. There was a problem that it took time. In addition, there is a problem that the spatial image of a very fine pattern may not be able to be accurately measured because the spatial image may be affected by uneven coating or development of the photosensitive material. Was.

In the second conventional method, the problems in the first conventional method can be largely solved. However, also in the second conventional method, the sensitivity of the CCD becomes unstable when X-rays of 10 to 250 nm and far ultraviolet light are used as the exposure light as described above. In particular, when far-ultraviolet light having a wavelength in the range of 100 to 200 nm is used, the sensitivity of the CCD is significantly reduced. For this reason, there has been a problem that accurate measurement of the aerial image is difficult.

The present invention has been made by paying attention to such problems existing in the prior art. It is an object of the present invention to provide a light intensity measuring element that can accurately measure the intensity of incident light without using a magnifying optical system.

Another object of the present invention is to provide an image pickup device capable of accurately measuring an incident aerial image without using a magnifying optical system.
Another object of the present invention is to provide an aerial image measurement method capable of directly observing the aerial image of a pattern in real time without printing it on a wafer or the like, and performing accurate and quick measurement of the aerial image. It is to provide a device.

It is a further object of the present invention to provide an exposure apparatus which can measure an aerial image of a pattern accurately and quickly and can perform accurate exposure based on the measurement result. It is in.

[0010]

According to a first aspect of the present invention, a light intensity measuring element for measuring the intensity of incident light includes a pair of light intensity measuring elements. Electrode (29, 30) and its electrode (2
9, 30), and a detecting means (33) for detecting information on the intensity of the incident light based on a change in characteristics of the conductive material (31). Things.

According to the first aspect of the present invention, when the conductive material receives the incident light, the characteristics of the conductive material change according to the intensity of the incident light. By detecting this characteristic change, the intensity of the incident light can be directly measured without burning the incident light onto a substrate and developing the substrate, or using a CCD.

The invention according to claim 2 of the present application is the invention according to claim 1, wherein the conductive material (31)
Is characterized in that the light is dissipated from between the electrodes (29, 30) by receiving the incident light.

According to the second aspect of the present invention, in addition to the function of the first aspect, when the conductive material receives incident light, the conductive material is changed according to the intensity of the incident light. The dissipative state changes. Accordingly, the electric resistance characteristic between the pair of electrodes changes, so that the intensity of the incident light can be measured by detecting the electric resistance between the electrodes.

According to a third aspect of the present invention, in the first or second aspect, the conductive material (31) is at least one of indium tin oxide and antimony tin oxide. It is characterized by including.

According to the third aspect of the present invention, in addition to the effects of the first or second aspect,
The absorption spectra of indium tin oxide and antimony tin oxide show strong absorption particularly in a wavelength region of 250 nm or less. Therefore, particularly when the incident light has a short wavelength of 250 nm or less, the conductive material exhibits strong light absorption characteristics, and high-sensitivity measurement can be performed.

The invention according to claim 4 of the present application relates to an image pickup element (24, 24) for detecting an incident aerial image.
35) A method according to claim 35, wherein a plurality of the light intensity measuring elements (25) according to any one of claims 1 to 3 are arranged so as to be continuous.

In the fourth aspect of the present invention, when an aerial image is incident on the image sensor, the characteristics of the conductive material of each light intensity measuring element change in accordance with the intensity of the incident light. Thereby, by detecting the characteristic change of the conductive material, the aerial image can be measured without printing and developing the aerial image on the substrate or using a CCD.

Further, the present invention relates to an aerial image measuring apparatus.
The invention according to (4) is an aerial image measurement device (22) that measures an aerial image of a predetermined pattern projected via a projection optical system (17).
4, 35), and the aerial image of the predetermined pattern is received by the imaging device (24, 35).

According to the fifth aspect of the present invention, the spatial image of the pattern is directly observed in real time without taking the troublesome method of printing the spatial image of the pattern on a wafer or the like, and then developing and observing the image. can do.

The invention according to claim 6 of the present invention relates to an exposure apparatus for projecting and transferring a circuit pattern formed on a mask (R) onto a substrate (W) via a projection optical system (17). An apparatus is provided with the aerial image measuring device (22) according to claim 5.

According to the sixth aspect of the present invention, an aerial image measuring device can measure an aerial image of a pattern accurately and quickly, and perform accurate exposure efficiently based on the measurement result. Can be.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 to 1 show a first embodiment in which the present invention is embodied in an exposure apparatus for manufacturing a semiconductor device and an aerial image measuring apparatus used therein.
Explanation will be given based on FIG.

As shown in FIG. 1, in the exposure apparatus of this embodiment, an ArF excimer laser beam (wavelength: 193 nm) and an F ₂ excimer laser beam (wavelength:
157 nm) is emitted. Exposure light, which is incident light emitted from the light source 11, is provided by an optical integrator 13 such as a fly-eye lens.
And the illumination optical system 12 including the condenser lens 14,
The illuminance distribution is made uniform. And this exposure light is
The light is irradiated onto a reticle R as a mask placed and held on a reticle stage 16 via a mirror 15. A fine circuit pattern is formed on the reticle R.

The exposure light having passed through the reticle R enters the projection optical system 17. As a result, an image (spatial image) of the pattern on the reticle R is projected via the projection optical system 17 onto a wafer W as a substrate placed and held on a wafer stage 18 in a reduced state. On the wafer W, a photosensitive material such as a photoresist having photosensitivity to the exposure light is applied, and the pattern on the reticle R is transferred onto the wafer W. Here, the wafer stage 18 is moved and adjusted by a driving device 19 in a direction orthogonal to the optical axis of the projection optical system 17 while a two-dimensional position is detected by an interferometer (not shown). . Then, an image of the pattern on the reticle is repeatedly projected and transferred onto a plurality of shot areas partitioned on the wafer W.

In the exposure apparatus configured as described above, the projection is performed via the projection optical system 17 while the aerial image measurement device 22 is mounted and held on the wafer stage 18 instead of the wafer W. An aerial image of the pattern is to be measured. That is, the aerial image measuring device 22
Has a measurement wafer 23 as shown in FIG. 2, and a plurality of image sensors 24 are arranged on the measurement wafer 23 so as to be two-dimensionally continuous. Then, in an exposure step in which a spatial image of a pattern is projected and transferred onto the wafer W, the measurement wafer 23 is placed on the wafer stage 18, for example, every several lots. Thereby, in each of the image sensors 24, a spatial image of the pattern formed on the reticle R is received and detected one by one.

As shown in FIGS. 3 and 4, a plurality of light intensity measuring elements 25 are two-dimensionally arranged in each of the imaging elements 24 so as to be continuous in the X-axis direction and the Y-axis direction. . The light intensity measuring elements 25 measure the intensity of the exposure light that forms a spatial image of the pattern.

Each of the image pickup devices 24 includes a plurality of positive side distribution lines 2 on an insulating substrate 26 such as a wafer W.
7 are formed so as to extend in the Y-axis direction while securing insulation therebetween, and are arranged in parallel with each other. On the positive distribution line 27, a plurality of negative distribution lines 2
Numerals 8 are formed so as to extend in the X-axis direction while securing insulation between each other and with the plus side distribution line 27, and are arranged in parallel with each other.

In the vicinity of the intersection of each of the plus side distribution lines 27 and the minus side distribution lines 28, the two distribution lines 27, 2
A pair of plus side electrodes 29 and minus side electrodes 30 constituting the light intensity measuring element 25 are provided on the projection 8 respectively. A conductive material 31 is interposed between the electrodes 29 and 30. The conductive material 31 is, for example, a metal thin film of chromium (Cr) or the like, indium tin oxide (IT
O) or a thin film or coating film of antimony tin oxide (ATO) or a conductive plastic coating film. Note that FIG. 4 shows only the pair of electrodes 29 and 30 and the conductive material 31 interposed between the pair of electrodes 29 and 30 to avoid complication of the drawing.

Then, when the spatial image of the pattern is incident on the image pickup device 24 and each light intensity measuring element 25 receives the exposure light, the conductive material 31 absorbs the exposure light. As a result, as shown in FIG. 6, the conductive material 31 is dissipated from between the electrodes 29 and 30 according to the irradiation energy (intensity) of the received exposure light, and the electrical resistance characteristic between the electrodes 29 and 30 is received. It changes according to the intensity of the exposure light. That is, as the irradiation energy of the exposure light to the conductive material 31 increases, the conductive material 31 evaporates more due to photolysis or heat generation, and the electrodes 29, 3
The electrical resistance between zero is increased.

Here, as shown in FIGS. 3 to 5, the electrodes 29 and 30 are connected to the DC power supply 32 and the potential difference as the detecting means via the plus side distribution line 27 and the minus side distribution line 28, respectively. A total of 33 are connected. Then, by scanning each of the plus side distribution line 27 and the minus side distribution line 28, the position between the electrodes 29, 30 of each light intensity measuring element 25 is specified, and the electrodes 29, 30 are specified.
The potential difference between them is detected. Thereby, each electrode 2
The electrical resistance is measured every 9, 30 hours.

Next, the operation of the aerial image measuring device of the exposure apparatus configured as described above will be described. In this exposure apparatus, in the exposure step in which the spatial image of the pattern formed on the reticle R is projected and transferred onto the wafer W via the projection optical system 17, for example, every several lots, The measurement wafer 23 is placed on the wafer stage 18. Then, the driving device 19 of the wafer stage 18 is driven with respect to the plurality of imaging devices 24 arranged on the measurement wafer 23, and the position of the imaging device 24 in the optical axis direction of the projection optical system 17 is adjusted. Is gradually changed, and the image of the pattern on the reticle R is sequentially projected one shot at a time.

Here, the spatial image of the pattern is received by the image sensor 24, and the spatial image is converted into light intensity measuring elements 25 arranged two-dimensionally on the image sensor 24.
It can be understood as a distribution of electric resistance between the electrodes 29 and 30 for each. By comparing the aerial image of each shot measured in this way with, for example, the contrast of the aerial image, the position of the optimal imaging surface of the projection optical system 17 at the time of measurement, the imaging characteristics, and the like can be accurately determined. Can be measured. Then, by adjusting the imaging characteristics of the projection optical system 17 based on the measurement result, the subsequent exposure operation can be performed accurately.

Therefore, according to the first embodiment configured as described above, the following effects can be obtained. (A) In the light intensity measuring element 25 of the first embodiment, a conductive material 31 that undergoes a change in characteristics according to the intensity of the exposure light when light is received is interposed between the pair of electrodes 29 and 30. I have.

Therefore, by detecting the change in the characteristic, the intensity of the exposure light can be measured without printing and developing the exposure light on a wafer or using the CCD. Therefore, the intensity of the exposure light can be measured accurately, with high sensitivity, and quickly without being affected by unevenness of application and development of the photosensitive material and aberration of the magnifying optical system attached to the CCD. .

(B) In the light intensity measuring element 25 of the first embodiment, the conductive material 31 is dissipated from between the electrodes 29 and 30 by receiving the exposure light, so that the electric resistance characteristic is changed. I have.

For this reason, when the conductive material 31 receives the exposure light, the conductive material 3 is changed according to the intensity of the exposure light.
The dissipative state of 1 changes, and the electrical resistance characteristics between the pair of electrodes 29 and 30 change. Therefore, by detecting the electric resistance between the electrodes 29 and 30, the intensity of the exposure light can be easily and accurately measured.

(C) In the light intensity measuring element 25 of the first embodiment, the conductive material 31 is formed of a thin film of indium tin oxide, antimony tin oxide, or the like.
For this reason, especially when the exposure light is ultraviolet light of 250 nm or less, the conductive material 31 exhibits strong light absorption characteristics, and light intensity measurement can be performed with higher sensitivity.

(D) In the image pickup device 24 of the first embodiment, the light intensity measuring devices 25 having the above-described configuration are two-dimensionally arranged so as to be continuous in plural numbers in the X-axis direction and the Y-axis direction. Have been.

For this reason, when exposure light forming an aerial image is incident on the image pickup device 24, the electric resistance characteristic between the electrodes 29 and 30 of each light intensity measurement device 25 changes according to the intensity of the exposure light. Therefore, by detecting changes in these electric resistance characteristics, the aerial image is printed and developed on a wafer, and without using the CCD,
The aerial image can be directly captured. Therefore, an aerial image can be measured accurately, with high sensitivity, and quickly without being affected by unevenness in application and development of the photosensitive material, aberration of the magnifying optical system attached to the CCD, and the like.

(E) In the aerial image measuring device 22 of the first embodiment, the image of the pattern on the reticle R is received by using the imaging device 24 having the above-described configuration. For this reason, it is possible to directly observe the image in real time without taking the troublesome method of printing a pattern image, that is, an aerial image on a wafer or the like, and then developing and observing the image. Moreover, when measuring the aerial image, the CCD
There is no need to use. Therefore, the measurement of the aerial image can be accurately performed without being affected by unevenness of application or development of the photosensitive material, aberration of the magnifying optical system attached to the CCD, or the like.
Highly sensitive and quick.

(F) In the exposure apparatus of the first embodiment,
The aerial image measuring device 22 having the above configuration is provided. For this reason, the aerial image can be accurately, sensitively and quickly measured by the aerial image measuring device 22. Thus, the imaging characteristics of the projection optical system 17 can be accurately and quickly adjusted based on the measurement result. Therefore,
The accuracy of exposure of the pattern on the reticle R onto the wafer W can be improved, and the positioning operation and the like prior to exposure can be performed quickly, and the operation rate of the exposure apparatus can be improved.

(G) In the exposure apparatus of the first embodiment, the wavelength of the exposure light for illuminating the reticle R is preferably 10 to 250 nm, more preferably 100 to 200 nm.
It is set to be within the range of nm.

Here, when the exposure light is ultraviolet light or visible light having a wavelength longer than 250 nm,
Sufficient sensitivity can be obtained with a conventionally known imaging device such as a CCD, and even if an enlargement optical system is attached, the aberration is not so large. On the other hand, even when the exposure light is an X-ray having a wavelength shorter than 10 nm, the CCD or the like has sufficient sensitivity.

On the other hand, the exposure light is 10-25.
In the case of X-rays or far-ultraviolet light having a wavelength in the range of 0 nm, there is a problem that the sensitivity of the CCD becomes unstable, and the accuracy of aerial image measurement using the CCD is greatly reduced. In particular, the wavelength of the exposure light is 100 to 2
In the range of 00 nm, there is a problem that the sensitivity of the CCD is significantly reduced, and the accuracy of aerial image measurement using the CCD may be difficult.

However, the exposure apparatus of the first embodiment is provided with the aerial image measuring device 22 having the above-described configuration. For this reason, it is possible to configure an exposure apparatus that is compatible with a monochromatic light source having good center wavelength stability, such as excimer laser light of various wavelengths, while ensuring high resolution in the photolithography process. In particular, even when far-ultraviolet light and X-rays in the above wavelength range where direct measurement of an aerial image is difficult to use, direct measurement of an aerial image can be made possible by the aerial image measurement device 22. Thus, exposure can be performed accurately and quickly.

(Second Embodiment) Next, a second embodiment of the present invention will be described focusing on parts different from the first embodiment.

In the second embodiment, as shown in FIG. 7, by arranging a plurality of light intensity measuring elements 25 continuously in one direction, that is, one-dimensionally, the imaging element 3
5 are configured. Then, each light intensity measuring element 25
However, similarly to the first embodiment, a pair of electrodes 29 and 30
The structure has a conductive material 31 interposed therebetween.

That is, in the second embodiment, the plurality of plus side electrodes 29 and minus side electrodes 30 are
1 are alternately arranged. Each positive electrode 29 is connected to the positive terminal of the DC power supply 32 via the positive distribution line 27, and each negative electrode 30 is connected to the negative terminal of the DC power supply 32 via the negative distribution line 28. Have been.

Therefore, in the second embodiment, similarly to the first embodiment, when a spatial image is incident on the image sensor 35, the conductive material 31 of each light intensity measuring element 25 causes the exposure light to form the spatial image. Is dissipated in accordance with the strength of the wire, and its electrical resistance characteristics change. The electrical resistance between the electrodes 29 and 30 is measured by detecting the potential difference between the electrodes 29 and 30 in each light intensity measuring element 25 in a serial or parallel manner. For this reason, based on the measurement result of the electric resistance, the intensity of the exposure light at the arrangement position of each light intensity measuring element 25 can be measured, and a line-shaped aerial image can be directly captured as a whole of the imaging element 35.

Therefore, according to the second embodiment, the following effects are obtained in addition to the effects (a) to (c) and (e) to (g) in the first embodiment. be able to.

(H) The image sensor 35 of the second embodiment has a configuration in which the light intensity measuring elements 25 are arranged one-dimensionally. Therefore, the imaging element 35 is suitable as a so-called line sensor configuration capable of accurately and quickly measuring an aerial image.

(Modifications) The above embodiments of the present invention may be modified as follows. In each of the above embodiments, the conductive material 31 of the light intensity measuring element 25 is formed of a thin film or a coating film of indium tin oxide (ITO) or the like, and the conductive material 31 is changed to the electrodes 29 and 30 by receiving the exposure light. Dissipated from between, causing its conductive properties to change. On the other hand, the conductive material 31
May be constituted by a pyro element or the like, and the conductive substance 31 generates heat according to the intensity of the received exposure light, converts the heat into a potential difference, and detects the conductive property.

In this case, in addition to the effects substantially the same as those described in (A), (D) to (H) in each of the above-described embodiments, when the incidence of the exposure light is stopped, the conductive The effect is obtained that the substance 31 is cooled from the heat generation state, the conductive properties thereof are restored, and the light intensity measuring element 25 can be reused.

In the first embodiment, a plurality of image sensors 24 are arranged on the measurement wafer 23, and the measurement wafer 23 is placed on the wafer stage 18, and a pattern is formed on each image sensor 24. The aerial image was projected one shot at a time. On the other hand, one image sensor 24 is formed in a seal shape, and is pasted on one or a plurality of shot areas on the wafer W used for actual exposure. After projecting the aerial image onto the image sensor 24 on the wafer W to measure the aerial image, other shot areas on the wafer W may be sequentially exposed.

In this case, in addition to the effects substantially similar to the effects (a) to (g) in the first embodiment, it is necessary to prepare the measurement wafer 23 separately from the actual wafer W. Therefore, the effect that the measurement operation can be easily performed with a simple configuration can be obtained.

In each of the above-described embodiments, the conductive material 31 of the light intensity measuring elements 25 and 35 is configured to be dissipated from between the electrodes 29 and 30 by receiving the incident light, thereby deteriorating the conductive characteristics. On the other hand, a conductive gaseous substance is interposed in the space between the electrodes 29 and 30 as the conductive substance 31, and when the exposure light is incident, the gaseous substance is solidified between the electrodes 29 and 30. May be deposited. In this case, according to the intensity of the received exposure light, the degree of deposition of the gaseous substance is increased, and the conductive characteristics are increased.

Also in this case, substantially the same effects as those described in (A), (D) to (H) in the above embodiments can be obtained. In the above embodiments, the detection of the conductive characteristics of each light intensity measuring element 25 in the imaging elements 24 and 35 is performed by scanning or the like. On the other hand, an amplifier circuit is connected between the electrodes 29 and 30 of each light intensity measuring element 25, and each light intensity measuring element 25 is connected through the amplifier circuit.
May be directly detected for each light intensity measuring element 25 as an analog signal or a digital signal.

Also in this case, in addition to the effects substantially similar to the effects described in (A) to (H) in each of the above embodiments, the detection of the sensed aerial image is performed with higher accuracy. And scanning can be performed more quickly without the necessity of performing scanning or the like.

In the above embodiments, A is used as the exposure light.
The case where rF excimer laser light, F ₂ excimer laser light, or the like is used has been exemplified. On the other hand, for example, a single-wavelength laser beam in the infrared or visible region oscillated from a DFB semiconductor laser or a fiber laser is amplified by a fiber amplifier doped with, for example, erbium (or both erbium and yttrium), A harmonic converted to ultraviolet light using a nonlinear optical crystal may be used as exposure light.

In this case, for example, if the oscillation wavelength of the single-wavelength laser light is in the range of 1.51 to 1.59 μm, an eighth harmonic whose generation wavelength is in the range of 189 to 199 nm is output. In particular, the oscillation wavelength is set to 1.544 to 1.553.
If it is in the range of μm, an eighth harmonic within the range of 193 to 194 nm, that is, far ultraviolet light having substantially the same wavelength as the ArF excimer laser light can be obtained. Note that, as the single-wavelength oscillation laser light, an ytterbium-doped fiber laser is used.

In each of the above embodiments, the present invention is embodied in an exposure apparatus for manufacturing a semiconductor and an aerial image measuring apparatus, but in the present invention, for example, a circuit pattern on a photomask is projected and transferred onto a glass plate. In addition to an exposure apparatus for a liquid crystal display element, the present invention can be embodied as an exposure apparatus for manufacturing a micro device such as an imaging element and a thin film magnetic head, and an exposure apparatus for manufacturing a reticle, a photomask, and the like.

The aerial image measuring device 2 described in each of the above embodiments
In order to achieve the above-described functions, the exposure apparatus provided with 2 is configured such that each element constituting the exposure apparatus is mechanically (including piping), electrically (including wiring), and optically (including optical adjustment). They are combined and assembled.

[0063]

As described in detail above, according to the first aspect of the present invention, the intensity of incident light can be measured accurately, with high accuracy, and quickly.

According to the second aspect of the present invention, in addition to the effect of the first aspect, by detecting the electric resistance between the pair of electrodes, the intensity of the incident light can be easily reduced.
It can be measured accurately and quickly.

According to the third aspect of the present invention, in addition to the effect of the first or second aspect,
In particular, when the incident light has a short wavelength of 250 nm or less, the conductive material exhibits strong light absorption characteristics, and high-sensitivity measurement can be performed.

Further, according to the invention of claim 4 of the present application, an incident aerial image can be measured accurately, with high accuracy and quickly. Further, according to the invention of claim 5 of the present application, the aerial image can be directly observed in real time, and the aerial image can be measured accurately and quickly.

According to the invention of claim 6 of the present application, an aerial image can be measured accurately, with high accuracy and quickly, and accurate exposure can be performed based on the measurement result. Can be performed accurately and quickly.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an exposure apparatus provided with an aerial image measurement device according to a first embodiment.

FIG. 2 is a perspective view showing a measurement wafer of the aerial image measurement device of FIG. 1;

FIG. 3 is a schematic configuration diagram illustrating a configuration of an image sensor on a measurement wafer.

FIG. 4 is an essential part perspective view showing a configuration of a light intensity measuring element in the image sensor.

FIG. 5 is an explanatory diagram relating to detection of intensity of exposure light received by a light intensity measuring element.

FIG. 6 is an explanatory diagram relating to a light receiving state of exposure light of a light intensity measuring element.

FIG. 7 is a schematic configuration diagram illustrating an image sensor of the aerial image measurement device according to the second embodiment.

[Explanation of symbols]

11 light source, 17 projection optical system, 22 aerial image measurement device, 24, 35 image pickup device, 25 light intensity measurement device, 2
Reference numeral 9 denotes a positive electrode as an electrode, 30 denotes a negative electrode as an electrode, 31 denotes a conductive material, 33 denotes a potentiometer as a detecting means, R denotes a reticle as a mask, and W denotes a wafer as a substrate.

Claims (6)

[Claims] 1. A light intensity measuring element for measuring the intensity of incident light, comprising: a pair of electrodes; a conductive material provided between the electrodes; and information on the intensity of the incident light based on a change in characteristics of the conductive material. A light intensity measuring element comprising: a detecting means for detecting. 2. The light intensity measuring element according to claim 1, wherein the conductive material is dissipated from between the electrodes by receiving the incident light. 3. The light intensity measuring element according to claim 1, wherein the conductive material contains at least one of indium tin oxide and antimony tin oxide. 4. An imaging device for detecting an incident aerial image, wherein a plurality of the light intensity measuring devices according to claim 1 are arranged so as to be continuous. Imaging device. 5. An aerial image measuring apparatus for measuring an aerial image of a predetermined pattern projected via a projection optical system, comprising: the imaging device according to claim 4, wherein the aerial image of the predetermined pattern is An aerial image measuring device that receives light with an image sensor. 6. An exposure apparatus for projecting and transferring a circuit pattern formed on a mask onto a substrate via a projection optical system, wherein the aerial image measurement apparatus according to claim 5 is provided.