JP2021100071A - Substrate processing apparatus and method for processing substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately remove a peripheral edge portion of a first substrate in a polymerization substrate in which a first substrate and a second substrate are joined. A substrate processing apparatus for processing a substrate, wherein a surface film is formed on the surface of the substrate, and the substrate processing apparatus is a polymerized substrate in which a first substrate and a second substrate are bonded to each other. The inside of the first substrate is provided with a peripheral modification portion that irradiates a laser beam to form a peripheral modification layer that serves as a base point for peeling of the peripheral portion along the boundary between the peripheral portion and the central portion to be removed. On the outer peripheral portion of the first substrate, a substrate exposed region is formed in which the surface of the first substrate is exposed by removing the surface film. [Selection diagram] FIG. 7

Description

The present disclosure relates to a substrate processing apparatus and a substrate processing method.

In Patent Document 1, as a device for performing edge trimming, a disk-shaped grinding tool provided with abrasive grains on the outer peripheral portion is rotated, and at least the outer peripheral surface of the grinding tool is linearly contacted with a semiconductor wafer to form a semiconductor. It is disclosed that the peripheral end portion of the wafer is ground in a substantially L shape. A semiconductor wafer is manufactured by laminating two silicon wafers.

Further, Patent Document 2 describes a method for processing a work piece, in which a work piece whose outer peripheral portion has been removed by a cutting blade is attached to a substrate, and then the back surface of the attached work piece is ground. It is disclosed that the thickness is set to a predetermined value.

Japanese Unexamined Patent Publication No. 9-216152 JP-A-2018-114581

The technique according to the present disclosure appropriately removes the peripheral edge portion of the first substrate in the polymerized substrate in which the first substrate and the second substrate are joined.

One aspect of the present disclosure is a substrate processing apparatus for processing a substrate, wherein a surface film is formed on the surface of the substrate, and the substrate processing apparatus is a polymerization in which a first substrate and a second substrate are bonded to each other. In the substrate, the inside of the first substrate is irradiated with a laser beam to form a peripheral modification layer that serves as a base point for peeling of the peripheral portion along the boundary between the peripheral portion and the central portion to be removed. A substrate exposed region is formed on the outer peripheral portion of the first substrate by removing the surface film to expose the surface of the first substrate.

According to the present disclosure, in a polymerized substrate in which a first substrate and a second substrate are bonded, a peripheral portion of the first substrate can be appropriately removed.

It is a side view which shows the structural example of a polymerization wafer. It is explanatory drawing which shows the outline of the substrate exposed area formed on the 1st wafer. It is a top view which shows the outline of the structure of the wafer processing system which concerns on this embodiment. It is explanatory drawing which shows an example of the main process in the semiconductor wafer manufacturing process. It is a top view which shows the formation example of the modified layer in the inside of a 1st wafer. It is a flow chart which shows an example of the main process in the semiconductor wafer manufacturing process. It is explanatory drawing which shows the formation example of the modified layer in the inside of the 1st wafer. It is explanatory drawing which shows the formation example of the modified layer in the inside of the 1st wafer. It is a top view which shows the outline of the structure of the wafer processing system which concerns on other embodiment. It is explanatory drawing which shows an example of the formation method of the substrate exposed area. It is explanatory drawing which shows the formation example of the substrate exposed area.

In recent years, in the manufacturing process of a semiconductor device, a polymer substrate in which a device such as a plurality of electronic circuits is formed on the surface (hereinafter referred to as "first substrate") and a second substrate are bonded to each other. , The back surface of the first substrate is ground and thinned.

By the way, normally, the peripheral edge of the first substrate is chamfered, but as disclosed in Patent Document 1, when the back surface of the first substrate is ground, the peripheral edge of the first substrate is formed. The part has a sharp and pointed shape (so-called knife edge shape). Then, chipping occurs at the peripheral edge of the first substrate, and the first substrate may be damaged. Therefore, so-called edge trimming is performed in which the peripheral edge of the first substrate is scraped in advance before the grinding process.

The grinding method described in Patent Document 2 described above is a grinding method for suppressing the formation of this knife edge shape on the outer peripheral portion of the wafer (first wafer). However, when the back surface of the first substrate bonded to the second substrate is ground and thinned by the method described in Patent Document 2, a chipping problem may occur due to the thinning of the first substrate. .. Specifically, for example, debris scattered when the first substrate is thinned collects in the chamber of the grinding device or in the drainage line, hinders the drainage in the device, or performs maintenance for removing the debris of the device. In some cases, the operating rate was reduced. Further, for example, there is a case where the debris adheres to the grinding surface of the first substrate, which makes it impossible to perform proper grinding. Therefore, there is room for improvement in conventional edge trim.

The technique according to the present disclosure has been made in view of the above circumstances, and in a polymerized substrate in which a first substrate and a second substrate are bonded, a peripheral portion of the first substrate is appropriately removed. Specifically, the inside of the first substrate is irradiated with a laser to form a peripheral modified layer along the boundary between the peripheral portion and the central portion of the first substrate to be removed, and the peripheral modified layer is formed. The peripheral edge is peeled off from the base point and removed (laser trimming). Hereinafter, the substrate processing apparatus and the substrate processing method according to the present embodiment will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

In the wafer processing system 1 as the substrate processing apparatus according to the present embodiment, as shown in FIG. 1, the first wafer W as the first substrate and the second wafer S as the second substrate are joined. The polymerized wafer T as the polymerized substrate is processed. Then, in the wafer processing system 1, the peripheral portion We of the first wafer W is removed, and the first wafer W is thinned. Hereinafter, in the first wafer W, the surface bonded to the second wafer S is referred to as a front surface Wa, and the surface opposite to the front surface Wa is referred to as a back surface Wb. Similarly, in the second wafer S, the surface bonded to the first wafer W is referred to as a front surface Sa, and the surface opposite to the front surface Sa is referred to as a back surface Sb. Further, in the first wafer W, the radial inner side of the peripheral edge portion We as the removal target is referred to as the central portion Wc.

The first wafer W is a semiconductor wafer such as a silicon substrate, and a device layer D including a plurality of devices is formed on the surface Wa. A surface film Fw is further formed on the device layer D, and is bonded to the surface film Fs of the second wafer S via the surface film Fw. Examples of the surface film Fw include an oxide film (SiO ₂ film, TEOS film), a SiC film, a SiCN film, and an adhesive. The peripheral edge portion We of the first wafer W is chamfered, and the cross section of the peripheral edge portion We becomes thinner toward the tip thereof. Further, the peripheral edge portion We is a portion that is removed in the edge trim described later, and is, for example, in the range of 0.5 mm to 3 mm in the radial direction from the outer end portion of the first wafer W.

The second wafer S is, for example, a wafer that supports the first wafer W. Surface films Fs are formed on the surface Sa of the second wafer S, and the peripheral edge is chamfered. Examples of the surface film Fs include an oxide film (SiO ₂ film, TEOS film), a SiC film, a SiCN film, and an adhesive. Further, the second wafer S functions as a protective material (support wafer) for protecting the device layer D of the first wafer W. The second wafer S does not have to be a support wafer, and may be a device wafer on which a device layer is formed as in the first wafer W. In such a case, the surface film Fs is formed on the surface Sa of the second wafer S via the device layer.

Since the peripheral portion We of the first wafer W is normally removed from the outer peripheral portion of the first wafer W by the laser trimming process described above, the bonding force of the peripheral portion We with the second wafer S is obtained. Pretreatment is being performed to eliminate the problem. As shown in FIG. 2, the pretreatment grinds the surface film Fw and the device layer D formed on the outer peripheral portion of the first wafer W prior to joining the first wafer W and the second wafer S. By exposing at least the surface Wa of the first wafer W, more preferably, the surface Wa is ground by a grinding member in order to completely expose the surface Wa. In the following description, the exposed portion of the first wafer W may be referred to as a “substrate exposed region Wed”, and the exposed surface of the first wafer W in the substrate exposed region Wed may be referred to as an “exposed surface Wad”. As a result, in the polymerized wafer T, the bonding region where the first wafer W and the second wafer S are bonded and the unbonded region where the first wafer W and the second wafer S are not bonded by the pretreatment are not bonded. A region is formed.

As shown in FIG. 3, the wafer processing system 1 has a configuration in which the loading / unloading station 2 and the processing station 3 are integrally connected. The carry-in / out station 2 carries in / out a cassette Ct capable of accommodating a plurality of polymerized wafers T (see FIGS. 1 and 2) to and from the outside, for example. The processing station 3 is provided with various processing devices that perform desired processing on the polymerized wafer T.

The loading / unloading station 2 is provided with a cassette mounting table 10. In the illustrated example, a plurality of, for example, three cassette Cts can be freely mounted in a row on the cassette mounting table 10 in the Y-axis direction. The number of cassettes Ct mounted on the cassette mounting table 10 is not limited to this embodiment and can be arbitrarily determined.

The loading / unloading station 2 is provided with a wafer transfer device 20 adjacent to the cassette mounting table 10 on the X-axis negative direction side of the cassette mounting table 10. The wafer transfer device 20 is configured to be movable on a transfer path 21 extending in the Y-axis direction. Further, the wafer transfer device 20 has, for example, two transfer arms 22 and 22 that hold and transfer the polymerized wafer T. Each transport arm 22 is configured to be movable in the horizontal direction, the vertical direction, the horizontal axis, and the vertical axis. The configuration of the transport arm 22 is not limited to this embodiment, and any configuration can be adopted. The wafer transfer device 20 is configured to be able to transfer the polymerized wafer T to the cassette Ct of the cassette mounting table 10 and the transition device 30 described later.

The carry-in / out station 2 is provided with a transition device 30 for delivering the polymerized wafer T adjacent to the wafer transfer device 20 on the X-axis negative direction side of the wafer transfer device 20.

The processing station 3 is provided with, for example, three processing blocks G1 to G3. The first processing block G1, the second processing block G2, and the third processing block G3 are arranged side by side in this order from the positive direction side of the X axis (the loading / unloading station 2 side) to the negative direction side.

The first processing block G1 is provided with an etching device 40, a cleaning device 41, and a wafer transfer device 50. The etching apparatus 40 and the cleaning apparatus 41 are arranged in a laminated manner. The number and arrangement of the etching apparatus 40 and the cleaning apparatus 41 are not limited to this. For example, the etching apparatus 40 and the cleaning apparatus 41 may be placed side by side in the X-axis direction, respectively. Further, the etching apparatus 40 and the cleaning apparatus 41 may be laminated respectively.

The etching apparatus 40 etches the ground surface of the first wafer W ground by the processing apparatus 80 described later. For example, a chemical solution (etching solution) is supplied to the ground surface, and the ground surface is wet-etched. As the chemical solution, for example, HF, HNO ₃ , H ₃ PO ₄ , TMAH, Choline, KOH and the like are used.

The cleaning device 41 cleans the ground surface of the first wafer W ground by the processing device 80 described later. For example, the brush is brought into contact with the ground surface to scrub clean the ground surface. A pressurized cleaning liquid may be used for cleaning the ground surface. Further, the cleaning device 41 may have a configuration for cleaning the back surface Sb of the second wafer S together with the ground surface of the first wafer W.

The wafer transfer device 50 is arranged, for example, on the Y-axis negative direction side of the etching device 40 and the cleaning device 41. The wafer transfer device 50 has, for example, two transfer arms 51, 51 that hold and transfer the polymerized wafer T. Each transport arm 51 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. The configuration of the transport arm 51 is not limited to this embodiment, and any configuration can be adopted. The wafer transfer device 50 is configured to be able to transfer the polymerized wafer T to the transition device 30, the etching device 40, the cleaning device 41, the reforming device 60 described later, and the peripheral edge removing device 61 described later.

The second processing block G2 is provided with a reforming device 60 as a peripheral surface reforming unit, a peripheral edge removing device 61 as a peripheral edge removing unit, and a wafer transfer device 70. The reformer 60 and the peripheral edge removing device 61 are arranged in a laminated manner. The number and arrangement of the reformer 60 and the peripheral edge removing device 61 are not limited to this. For example, the reformer 60 and the peripheral edge removing device 61 may be placed side by side in the X-axis direction, respectively. Further, the reformer 60 and the peripheral edge removing device 61 may be laminated respectively.

The reformer 60 irradiates the inside of the first wafer W with a laser beam (internal laser beam, for example, a YAG laser) to form a peripheral modification layer M1 and a split modification layer M2. The peripheral edge modification layer M1 serves as a base point when the peripheral edge portion We is peeled off in the edge trim described later. The split modified layer M2 serves as a base point for fragmenting the peripheral portion We to be removed.

The peripheral edge removing device 61 removes the peripheral edge portion We of the first wafer W, that is, edge trims, with the peripheral edge reforming layer M1 formed in the reforming device 60 as a base point. The edge trimming method can be arbitrarily selected.

The wafer transfer device 70 is arranged, for example, on the Y-axis positive direction side of the reformer 60 and the peripheral edge removing device 61. The wafer transfer device 70 has, for example, two transfer arms 71 and 71 that attract and hold the polymerized wafer T by a suction holding surface (not shown) and convey it. Each transport arm 71 is supported by an articulated arm member 72, and is configured to be movable in the horizontal direction, the vertical direction, the horizontal axis, and the vertical axis. The configuration of the transport arm 71 is not limited to this embodiment, and any configuration can be adopted. The wafer transfer device 70 is configured to be able to transfer the polymerized wafer T to the etching device 40, the cleaning device 41, the reforming device 60, the peripheral edge removing device 61, and the processing device 80 described later.

The third processing block G3 is provided with a processing device 80 as a processing unit. The number and arrangement of the processing devices 80 are not limited to the illustrated examples, and a plurality of processing devices 80 may be arbitrarily arranged.

The processing apparatus 80 has a rotary table 81. The rotary table 81 is rotatably configured around a vertical rotation center line 82 by a rotation mechanism (not shown). Two chucks 83 for sucking and holding the polymerized wafer T are provided on the rotary table 81. The chucks 83 are evenly arranged on the same circumference as the rotary table 81. The two chucks 83 can be moved to the delivery position A0 and the processing position A1 by rotating the rotary table 81. Further, each of the two chucks 83 is configured to be rotatable around a vertical axis by a rotation mechanism (not shown).

At the delivery position A0, the polymerization wafer T is delivered. A grinding unit 84 is arranged at the processing position A1 to grind the first wafer W. The grinding unit 84 has a grinding unit 85 having an annular shape and a rotatable grinding wheel (not shown). Further, the grinding portion 85 is configured to be movable in the vertical direction along the support column 86. Then, the chuck 83 and the grinding wheel are rotated in a state where the polymerization wafer T held by the chuck 83 is in contact with the grinding wheel.

The wafer processing system 1 described above is provided with a control device 90 as a control unit. The control device 90 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls the processing of the polymerized wafer T in the wafer processing system 1. Further, the program storage unit also stores a program for controlling the operation of the drive system of the above-mentioned various processing devices and transfer devices to realize the wafer processing described later in the wafer processing system 1. The program may be recorded on a computer-readable storage medium H and may be installed on the control device 90 from the storage medium H.

Next, wafer processing as a substrate processing method performed by using the wafer processing system 1 configured as described above will be described. In the present embodiment, in the external bonding device (not shown) of the wafer processing system 1, the first wafer W in which the substrate exposed region Wed is formed on the outer peripheral portion by the pretreatment device (not shown) in advance. , The second wafer S in which the substrate exposed region is not formed is joined to form the polymerized wafer T. Since the substrate exposed region Wed is formed on the first wafer W in this way, the bonded region Ac and the unbonded region Ae are formed on the polymerized wafer T (see FIG. 4).

First, the cassette Ct containing a plurality of the polymerization wafers T shown in FIG. 4A is placed on the cassette mounting table 10 of the loading / unloading station 2. Next, the polymerized wafer T in the cassette Ct is taken out by the wafer transfer device 20 and transferred to the transition device 30.

Subsequently, the wafer transfer device 50 takes out the polymerized wafer T of the transition device 30 and transfers it to the reformer 60. In the reforming apparatus 60, as shown in FIGS. 4B and 5, the peripheral reforming layer M1 and the split reforming layer M2 are sequentially formed inside the first wafer W (step P1 in FIG. 6). And step P2). In addition, in order to avoid the complexity of the illustration, the divisional modification layer M2 is not shown in the drawings after FIG. 4C. The order of formation of the peripheral modification layer M1 and the division modification layer M2 is arbitrary.

In forming the peripheral modification layer M1, the layered wafer T (first wafer W) is rotated, and the laser head (not shown) periodically irradiates the inside of the first wafer W with laser light. As a result, the peripheral modification layer M1 is formed in an annular shape concentric with the bonding region Ac (unbonded region Ae). The number of peripheral modification layers M1 formed in the thickness direction of the first wafer W1 is not limited to the illustrated example, and can be arbitrarily determined.

Further, inside the first wafer W, the back surface Wb side of the first wafer W is "upper" and the front surface Wa side is in the thickness direction (hereinafter, may be referred to as "vertical direction") from the peripheral modification layer M1. The crack C1 extends in the "downward" direction. The crack C1 extending upward from the peripheral modification layer M1 reaches, for example, the back surface Wb of the first wafer W. Further, the crack C1 extending downward reaches the exposed surface Wad of the substrate exposed region Wed.

In the wafer processing system 1 according to the present embodiment, prior to the formation of the peripheral modification layer M1, the boundary Ad between the bonding region Ac and the unbonded region Ae, which is a reference for the formation position of the peripheral modification layer M1, That is, the inner peripheral side end of the substrate exposed region Wafer is detected as the alignment position. The detection of such an alignment position is performed at an arbitrary position in the wafer processing system 1.

Here, when the device layer D is formed at the boundary Ad as the alignment position, the IR light for performing the alignment process may be blocked by the device layer D, and the boundary Ad may not be detected appropriately. However, in the polymerized wafer T according to the present embodiment, at least the surface Wa of the first wafer W is exposed by pretreatment on the outer peripheral portion of the first wafer W, specifically, by removing the surface film Fw and the device layer D. Therefore, the IR light is not blocked by the device layer D. That is, the boundary Ad between the bonded region Ac and the unjoined region Ae, which is the alignment position, can be appropriately detected.

When the peripheral modification layer M1 is formed inside the first wafer W, the laser head (not shown) and the stage (not shown) are relatively moved in the horizontal direction to move the peripheral modification layer M1 relatively. A split modified layer M2 extending in the radial direction of the first wafer W is formed on the outer side in the radial direction of the first wafer W.

When the split reforming layer M2 is formed inside the first wafer W, the polymerized wafer T is then transported from the reforming device 60 to the peripheral edge removing device 61 by the wafer transfer device 70.

In the peripheral edge removing device 61, as shown in FIG. 4C, the peripheral edge portion We of the first wafer W is removed from the peripheral edge modifying layer M1 and the crack C1 as base points (step P3 in FIG. 6). The method of removing the peripheral edge portion We can be arbitrarily determined, and for example, a blade as an insertion member having a wedge shape may be inserted. Further, for example, an air blow or a water jet may be injected to press and remove the peripheral portion We. In this way, in edge trimming, by applying an impact to the peripheral edge portion We of the first wafer W, the peripheral edge portion We is appropriately fragmented with the split modified layer M2 as a base point, and the peripheral edge modified layer is formed. It is peeled off from M1 as a base point. Further, in the polymerized wafer T according to the present embodiment, a substrate exposed region Wed is formed on the outer peripheral portion of the first wafer W, whereby the bonding force between the first wafer W and the second wafer S is not eliminated. Since the joining region Ae is formed, the peripheral portion We is removed more appropriately.

The polymerized wafer T from which the peripheral edge portion We of the first wafer W has been removed is then transported from the peripheral edge removing device 61 to the processing device 80 by the wafer transfer device 70. In the processing apparatus 80, as shown in FIG. 4D, the back surface Wb of the first wafer W is ground by the grinding portion 85, whereby the first wafer W is thinned to a desired thickness (FIG. 4). Step P4). After that, the ground surface of the first wafer W may be cleaned with the cleaning liquid using a cleaning liquid nozzle (not shown).

Here, in the polymerized wafer T according to the present embodiment, the peripheral edge portion We is removed by the peripheral edge removing device 61 prior to the thinning of the first wafer W by the processing apparatus 80. As a result, in the present embodiment, the thinning of the first wafer W, that is, the occurrence of the chipping problem during grinding is suppressed. Specifically, since the scattering of debris is suppressed during the grinding of the first wafer W, the debris accumulates in the drainage line in the processing apparatus 80, and the debris adheres to the ground surface of the first wafer W. It is suppressed.

When the first wafer W is thinned to a desired thickness in the processing apparatus 80, the polymerized wafer T is then conveyed to the cleaning apparatus 41 by the wafer transfer apparatus 70. In the cleaning device 41, the ground surface of the first wafer W is scrubbed (step P5 in FIG. 4). In the cleaning device 41, the back surface Sb of the second wafer S may be cleaned together with the ground surface of the first wafer W.

Next, the polymerized wafer T is transferred to the etching device 40 by the wafer transfer device 50. In the etching apparatus 40, the ground surface of the first wafer W is wet-etched with a chemical solution (step P6 in FIG. 4). Grinding marks may be formed on the ground surface ground by the processing device 80 described above. In this step P6, grinding marks can be removed by wet etching, and the ground surface can be smoothed.

After that, the polymerized wafer T that has been subjected to all the processing is transported to the transition device 30 by the wafer transfer device 50, and further transferred to the cassette Ct of the cassette mounting table 10 by the wafer transfer device 20. In this way, a series of wafer processing in the wafer processing system 1 is completed.

According to the above embodiment, since the peripheral portion We of the first wafer W is removed in advance by laser trimming, the knife edge shape is not formed on the first wafer W after grinding. Further, since the back surface Wb of the first wafer W from which the peripheral edge portion We has been removed in advance is ground in this way, scattering of debris is suppressed during grinding, thereby suppressing the chipping problem in the processing apparatus 80.

Furthermore, in the polymerized wafer T according to the present embodiment, since the surface film Fw and the device layer D have been removed from the outer peripheral portion of the first wafer W by pretreatment in advance, the peripheral modification layer M1 is formed. The alignment process can be appropriately performed, and the peripheral edge We can be easily removed by the peripheral edge removing device 61.

In the above embodiment, as shown in FIG. 4B, the peripheral modification layer M1 is placed along the boundary Ad between the bonded region Ac and the unbonded region Ae, that is, the inner peripheral end of the substrate exposed region Wed. The crack C1 was formed along the portion and the crack C1 was extended downward, but the method for forming the peripheral modification layer M1 is not limited to this.

For example, the crack C1 may be extended diagonally downward as shown in FIG. 7 (a), or the peripheral modification layer M1 may be radially inward from the boundary Wd as shown in FIGS. 7 (b) to 7 (e). Alternatively, it may be formed at a position slightly displaced outward in the radial direction. In such a case, the amount L in the radial direction from the boundary Wd on which the peripheral modification layer M1 is formed is preferably about 10 μm. At this time, the crack C1 extending upward from the peripheral modification layer M1 reaches the back surface Wb of the first wafer W, and the crack C1 extending downward reaches the exposed surface Wad in the substrate exposed region Wed. Control the evolution of C1. The growth direction of the crack C1 is controlled by adjusting, for example, the focusing state and pulse energy of the laser beam at the time of forming the peripheral modification layer M1 and the focusing position (height, circumferential position, etc.). In the technique according to the present disclosure, when the peripheral modification layer M1 is formed at a position slightly deviated from the boundary Wd in the radial direction, "the peripheral modification layer M1 is formed along the boundary Ad". It shall be included in the above.

Then, in this way, the crack C1 extending upward from at least the peripheral modification layer M1 reaches the back surface Wb of the first wafer W, and the crack C1 extending downward reaches the exposed surface Wad, thereby causing the peripheral edge removing device 61 to reach. The peripheral edge portion We can be appropriately removed with the peripheral edge modification layer M1 and the crack C1 as base points.

In this case, when the formation position of the peripheral modification layer M1 in the radial direction and the growth direction of the crack C1 are controlled, the crack C1 reaches the inner peripheral side end portion of the exposed surface Wafer of the substrate exposed region Wafer. If this is not done, a part of the peripheral edge We may be scattered as debris when grinding the first wafer W in the processing apparatus 80. However, according to the above embodiment, as shown in FIG. 4C, most of the peripheral edge We is removed in advance, and the deviation amount L from the boundary Ad where the peripheral modification layer M1 is formed is 10 μm. Since it is only a degree, the scattered debris becomes minute and the occurrence of the chipping problem is suppressed.

When removing the peripheral edge We of the first wafer W, in addition to the peripheral modification layer M1 and the split modification layer M2, the peripheral edge We is peeled off in the reformer 60 inside the first wafer W. An internal surface modification layer serving as a base point may be further formed. In such a case, the reformer 60 constitutes an internal surface reformer according to the technique of the present disclosure.

Specifically, as shown in FIG. 8A, inside the first wafer W, a peripheral modification layer M1 along the boundary Ad between the central portion Wc and the peripheral portion We of the first wafer W is provided. , The internal surface modification layer M3 formed along the surface direction of the first wafer W is formed. At this time, the peripheral modification layer M1 is preferably located radially inside the boundary Ad. Further, the inner surface modified layer M3 and the crack C3 extending from the inner surface modified layer M3 are each above the final finished surface of the first wafer W after thinning, and the substrate exposed region Wed is exposed. It is preferably located on the surface Wa side of the surface Wad. That is, it is preferable that the internal surface modification layer M3 and the crack C3 are formed at a position where the peripheral edge portion We can be appropriately removed and the first wafer W is removed by grinding in the processing apparatus 80.

Then, by forming the inner surface modification layer M3 in this way, the front surface Wa side and the back surface Wb side of the first wafer W in the peripheral edge portion We are edge-cut with the inner surface modification layer M3 and the crack C3 as boundaries. As a result, it is possible to appropriately prevent the crack C1 from extending below the final finished surface of the first wafer W.

When the internal surface modification layer M3 is formed in addition to the peripheral modification layer M1 and the split modification layer M2 inside the first wafer W in this way, the peripheral edge We as the removal target is shown in FIG. 8 (b). As shown, the peripheral modified layer M1, the crack C1, the inner surface modified layer M3, and the crack C3 are removed as starting points. Since the front surface Wa side and the back surface Wb side of the first wafer W are trimmed as described above, the peripheral edge portion We can be appropriately removed and debris is generated when the first wafer W is ground, that is, the above. The chipping problem can be suppressed more appropriately.

The order of formation of the peripheral modification layer M1 and the inner surface modification layer M3 is not particularly limited. However, for example, by forming the inner surface modification layer M3 before the peripheral modification layer M1, it is possible to more easily control that the crack C1 extends downward when the peripheral modification layer M1 is formed. it can.

The wafer processing system 1 in the above embodiment includes an etching device 40, a cleaning device 41, a reforming device 60, a peripheral edge removing device 61, and a processing device 80, but the configuration of the wafer processing system 1 is also limited to this. It's not something.

For example, in the above embodiment, the thinning of the first wafer W is performed by the processing apparatus 80 provided in the wafer processing system 1, but the thinning of the first wafer W is performed outside the wafer processing system 1. You may. That is, in the wafer processing system 1, the processing apparatus 80 may be omitted, and the processing apparatus 80 may be provided outside the wafer processing system 1.

Further, for example, in the above embodiment, the polymerized wafer T in which the first wafer W in which the substrate exposed region Wed is formed on the outer peripheral portion and the second wafer S in which the substrate exposed region is not formed is bonded is a wafer. Although it was carried into the processing system 1, these pretreatments and joining treatments may be performed inside the wafer processing system 1. That is, the pretreatment device 100 as the pretreatment section and the joining device 110 as the joining section may be provided inside the wafer processing system 1. In such a case, the arrangement of the pretreatment device 100 and the joining device 110 is arbitrary, but as shown in FIG. 9, for example, even if they are stacked and arranged on the first processing block G1 and the second processing block G2, respectively. Good.

When the pretreatment device 100 is provided in the wafer processing system 1 in this way, the pretreatment device 100 forms a substrate exposed region Wed which is an unbonded region Ae on the outer peripheral portion of the first wafer W. Specifically, as shown in FIG. 10, for example, the grinding member 102 is pressed against the surface film Fw formed on the outer peripheral portion of the first wafer W that is attracted and held by the chuck 101, and the first wafer is in such a state. By rotating W, the surface film Fw and the device layer D on the outer peripheral portion are removed. At this time, as shown in FIG. 11, the exposed surface Wad of the substrate exposed region Wed formed on the outer peripheral portion of the first wafer W is the final finished surface E of the first wafer W after being thinned in the polymerized wafer T. It is preferably located above.

The surface film Fw and the device layer D in the pretreatment device 100 may be removed by, for example, polishing or cutting instead of grinding by the above-mentioned grinding member 102.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The above embodiments may be omitted, replaced or modified in various forms without departing from the scope of the appended claims and their gist.

1 Wafer processing system 60 Reformer Ad Boundary Fw Surface film W 1st wafer Wa Surface Wc Central part We Peripheral part Wed Substrate exposed area M1 Peripheral reforming layer S 2nd wafer T Polymerized wafer

Claims (15)

It is a substrate processing device that processes substrates.
A surface film is formed on the surface of the substrate.
The substrate processing apparatus is
In a polymerized substrate in which a first substrate and a second substrate are joined, the inside of the first substrate is irradiated with a laser beam to peel off the peripheral portion along the boundary between the peripheral portion and the central portion to be removed. It is provided with a peripheral modification part that forms a peripheral modification layer that serves as a base point for
A substrate processing apparatus in which a substrate exposed region in which the surface of the first substrate is exposed by removing the surface film is formed on the outer peripheral portion of the first substrate. An internal surface modification portion is provided which irradiates the inside of the first substrate with a laser beam to form an internal surface modification layer which is a base point for peeling of the peripheral portion along the surface direction at the peripheral portion. The substrate processing apparatus according to claim 1. A control unit for controlling the operation of the peripheral surface modifying unit and the internal surface modifying unit is provided.
The control unit
The peripheral modification layer is placed radially inside the inner peripheral side end of the substrate exposed region.
Claimed to control the operation of the peripheral surface modifying portion and the internal surface modifying portion so that the internal surface modifying layer is formed on the surface side of the exposed surface of the first substrate in the substrate exposed region. Item 2. The substrate processing apparatus according to item 2. The substrate processing apparatus according to any one of claims 1 to 3, further comprising a joint portion for joining the surface of the first substrate and the surface of the second substrate. The substrate processing apparatus according to claim 3, further comprising a pretreatment portion for removing a surface film on the outer peripheral portion of the first substrate before joining to form the substrate exposed region. The substrate processing apparatus according to any one of claims 1 to 5, further comprising a peripheral edge removing portion that peels off the peripheral edge portion from the modified layer formed inside the first substrate as a base point. Any one of claims 1 to 6, wherein the polymerized substrate in which the first substrate and the second substrate are bonded includes a processed portion for grinding and thinning the back surface of the first substrate. The substrate processing apparatus according to. It is a substrate processing method that processes a substrate.
A surface film is formed on the surface of the substrate.
In a polymerized substrate in which a first substrate and a second substrate are bonded, a laser beam is irradiated to the inside of the first substrate along the boundary between the peripheral portion and the central portion of the removal target of the first substrate. Including forming a peripheral modification layer that serves as a base point for peeling of the peripheral portion.
A substrate processing method in which a substrate exposed region in which the surface of the first substrate is exposed by removing the surface film is formed on the outer peripheral portion of the first substrate. 8. The eighth aspect of the present invention includes irradiating the inside of the first substrate with a laser beam to form an internal surface modification layer which is a base point for peeling of the peripheral edge portion along the surface direction at the peripheral edge portion. The substrate processing method described. The peripheral modification layer is formed radially inward from the inner peripheral side end portion of the substrate exposed region.
The substrate processing method according to claim 9, wherein the internal surface modification layer is formed on the surface side of the exposed surface of the first substrate in the substrate exposed region. The substrate processing method according to any one of claims 8 to 10, which comprises joining the surface of the first substrate and the surface of the second substrate. The substrate processing method according to claim 11, further comprising removing the surface film on the outer peripheral portion of the first substrate before joining to form the substrate exposed region. The substrate processing method according to any one of claims 8 to 12, which comprises removing the peripheral edge portion with the modified layer formed inside the first substrate as a base point. The invention according to any one of claims 8 to 13, which comprises grinding and thinning the back surface of the first substrate in the polymerized substrate to which the first substrate and the second substrate are bonded. The substrate processing method described. Including detecting the inner peripheral side end of the substrate exposed region as an alignment position.
The substrate processing method according to any one of claims 8 to 14, wherein the peripheral modification layer is formed along the alignment position.

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