Substrate processing system and program

Abstract

To provide a substrate processing system and a program that, in an overlapped substrate in which substrates are joined to each other, appropriately removes a peripheral part of one substrate.SOLUTION: A substrate processing system processes an overlapped substrate T in which a first substrate W and a second substrate S are joined to each other, and has: a modified layer forming device that forms a modified layer M inside the first substrate; a processing device that performs processing of reducing the thickness of the first substrate; a program storage unit that stores a program; and a control unit that has a computer for operating the program. A substrate processing method includes: emitting a laser beam L from a processing surface side of the first substrate in the overlapped substrate to form a modified layer inside the first substrate along the boundary between a peripheral part We and a center part Wc of an object to be removed in the first substrate, with the modified layer forming device; and while performing processing of reducing the thickness of the first substrate from the side of a processing surface Wg, peeling off and removing the peripheral part from the first substrate with the modified layer as a starting point, with the processing device.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority based on Japanese Patent Application No. 2018-47159, filed March 14, 2018, and Japanese Patent Application No. 2018-87711, filed April 27, 2018, the contents of which are incorporated herein by reference.

[0002] The present invention relates to a substrate processing system and a program. [Background technology]

[0003] In recent years, in the manufacturing process of semiconductor devices, a semiconductor wafer (hereinafter referred to as a wafer) having a plurality of electronic circuits and other devices formed on its surface is thinned by grinding the backside of the wafer. If this thinned wafer is transported as is or subjected to subsequent processing, there is a risk of warping or cracking of the wafer. Therefore, in order to reinforce the wafer, for example, the wafer is attached to a support substrate.

[0004] Generally, the peripheral edge of a wafer is chamfered. However, as described above, when the wafer is ground, the peripheral edge of the wafer becomes sharp (a so-called knife-edge shape). This can cause chipping at the peripheral edge of the wafer, which can damage the wafer. Therefore, so-called edge trimming is performed to remove the peripheral edge of the wafer before grinding.

[0005] For example, Patent Document 1 discloses a vertical-axis type edge grinding device as a device for edge trimming. When using this edge grinding device to grind the peripheral portion of a wafer, first, a wafer with a support substrate attached is fixed to a table, and the table is rotated around an axis parallel to the vertical axis. Next, the spindle is rotated to rotate a wheel, which is a grinding tool, and then the spindle is moved vertically to bring the grinding surface of the wheel into contact with the wafer, thereby grinding the peripheral portion of the wafer. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-216152 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the edge grinding device described in Patent Document 1, the vertical movement of the spindle may not be constant due to various factors, such as tolerances. In such cases, the vertical movement of the wheel may not be properly controlled, and grinding may occur down to the surface of the support substrate. Therefore, there is room for improvement in conventional edge trimming.

[0008] The present invention has been made in view of the above circumstances, and has an object to appropriately remove the peripheral edge portion of one substrate in a laminated substrate formed by bonding two substrates together. [Means for solving the problem]

[0009] One aspect of the present invention for solving the above-mentioned problems is a substrate processing system for processing a laminated substrate in which a first substrate and a second substrate are bonded together, the system comprising: a modified layer forming device having a holder for holding the laminated substrate and irradiating the first substrate held in the holder with laser light to form a modified layer inside the first substrate; a processing device having a second holder for holding the laminated substrate and performing a processing process to reduce the thickness of the first substrate held in the second holder; a program storage unit for storing a program; and a control device having a computer that reads the program from the program storage unit and operates the program, The program is a program that runs on the computer of the control device that controls the substrate processing system to execute a substrate processing method on the substrate processing system, and the substrate processing method includes: irradiating laser light from the processing surface side of the first substrate in the laminated substrate by the modified layer forming device, and forming a modified layer inside the first substrate along the boundary between the peripheral portion and the central portion of the first substrate to be removed; and peeling and removing the peripheral portion from the first substrate using the modified layer as a base point while performing a processing process by the processing device to reduce the thickness of the first substrate from the processing surface side. [Effects of the Invention]

[0010] According to one aspect of the present invention, in a laminated substrate in which substrates are bonded together, the peripheral edge portion of one substrate can be appropriately removed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a plan view schematically illustrating an outline of the configuration of a substrate processing system according to a first embodiment. [Figure 2] FIG. 2 is a side view showing an outline of the configuration of an overlapping wafer. [Figure 3] FIG. 2 is a side view showing the outline of the configuration of the modified layer forming device. [Figure 4] FIG. 10 is a vertical cross-sectional view showing a state in which a modified layer is formed on a wafer to be processed. [Figure 5]FIG. 10 is a plan view showing a state in which a modified layer is formed on the wafer to be processed. [Figure 6] FIG. 2 is a side view showing an outline of the configuration of a grinding unit of the processing device. [Figure 7] 2A to 2C are explanatory views showing the state of a wafer to be processed in main steps of wafer processing according to the first embodiment. [Figure 8] 5A to 5C are explanatory views showing the state of a wafer to be processed in main steps of wafer processing according to a modified example of the first embodiment. [Figure 9] FIG. 10 is a plan view schematically illustrating an outline of the configuration of a substrate processing system according to a second embodiment. [Figure 10] FIG. 2 is a side view showing an outline of the configuration of the peripheral edge removing device. [Figure 11] 10A to 10C are explanatory views showing the state of a wafer to be processed in main steps of wafer processing according to a second embodiment. [Figure 12] 10A to 10C are explanatory views showing the state of a wafer to be processed in main steps of wafer processing according to another embodiment. [Figure 13] 10A to 10C are explanatory views showing the state of a wafer to be processed in main steps of wafer processing according to another embodiment. [Figure 14] FIG. 10 is a vertical cross-sectional view showing a modified layer formed on a wafer to be processed in another embodiment. [Figure 15] 10A and 10B are explanatory views showing a state in which a modified layer is formed on a wafer to be processed in another embodiment. [Figure 16] FIG. 10 is a plan view showing a state in which a modified layer is formed on a wafer to be processed in another embodiment. [Figure 17] FIG. 10 is a plan view showing a state in which a modified layer is formed on a wafer to be processed in another embodiment. [Figure 18] FIG. 10 is a plan view showing a state in which a modified layer is formed on a wafer to be processed in another embodiment. [Figure 19] FIG. 10 is a vertical cross-sectional view showing a modified layer formed on a wafer to be processed in another embodiment. [Figure 20] FIG. 2 is a side view showing the outline of the configuration of the interface treatment device. [Figure 21]FIG. 10 is a plan view showing a state in which modified grooves are formed in a wafer to be processed in another embodiment. [Figure 22] FIG. 10 is a plan view showing a modified surface formed on a wafer to be processed in another embodiment. [Figure 23] 10A to 10C are explanatory views showing the state of a wafer to be processed in main steps of wafer processing according to another embodiment. [Figure 24] FIG. 2 is a side view showing the outline of the configuration of the interface treatment device. [Figure 25] FIG. 2 is a side view showing an outline of the configuration of the processing apparatus. [Figure 26] FIG. 10 is a vertical cross-sectional view showing a modified surface formed inside a wafer to be processed in another embodiment. [Figure 27] 27 is an explanatory diagram of a vertical cross section showing how the modified surface shown in FIG. 26 is formed. FIG. [Figure 28] FIG. 10 is a vertical cross-sectional view showing a state in which a modified surface is formed on a device layer of a wafer to be processed in another embodiment. [Figure 29] 29 is an explanatory diagram of a vertical cross section showing how the modified surface shown in FIG. 28 is formed. FIG. [Figure 30] 10A to 10C are explanatory views showing the state of a wafer to be processed in main steps of wafer processing according to another embodiment. [Figure 31] FIG. 10 is a plan view showing a state in which the wafer to be processed is eccentric in the overlapping wafer. [Figure 32] FIG. 10 is an explanatory diagram illustrating a case where the modified layer is located radially inward from the inner periphery of the modified surface. [Figure 33] FIG. 10 is an explanatory diagram illustrating a case where the modified layer is located radially outward from the inner periphery of the modified surface. [Figure 34] FIG. 2 is a side view showing an outline of the configuration of the processing apparatus. [Figure 35] FIG. 10 is a plan view schematically illustrating the configuration of a substrate processing system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0013] First, a first embodiment of the present invention will be described. Fig. 1 is a plan view schematically illustrating the configuration of a substrate processing system 1 according to the first embodiment. In the following, to clarify the positional relationships, mutually orthogonal X-axis, Y-axis, and Z-axis directions are defined, and the positive Z-axis direction is defined as the vertically upward direction.

[0014] 2, the substrate processing system 1 bonds a process target wafer W as a first substrate and a support wafer S as a second substrate to form an overlapped wafer T as an overlapped substrate, and then thins the process target wafer W. Hereinafter, the surface of the process target wafer W to be processed (the surface opposite to the surface bonded to the support wafer S) will be referred to as the "processing surface Wg," and the surface opposite to the processing surface Wg will be referred to as the "non-processing surface Wn." Furthermore, the surface of the support wafer S to be bonded to the process target wafer W will be referred to as the "bonding surface Sj," and the surface opposite to the bonding surface Sj will be referred to as the "non-bonding surface Sn."

[0015] The wafer W to be processed is a semiconductor wafer such as a silicon wafer, and has a plurality of devices formed on the non-processing surface Wn. The peripheral edge of the wafer W to be processed is chamfered, and the thickness of the cross section of the peripheral edge decreases toward the tip.

[0016] The support wafer S is a wafer that supports the processed wafer W. The support wafer S also functions as a protective material that protects devices on the non-processing surface Wn of the processed wafer W. When multiple devices are formed on the bonding surface Sj of the support wafer S, a device layer (not shown) is formed on the bonding surface Sj in the same manner as the processed wafer W.

[0017] As shown in FIG. 1, the substrate processing system 1 has a configuration in which a loading / unloading station 2 through which cassettes Cw, Cs, and Ct, each capable of accommodating a plurality of wafers W to be processed, a plurality of support wafers S, and a plurality of overlapping wafers T, are loaded and unloaded from the outside, and a processing station 3 equipped with various processing devices that perform predetermined processing on the wafers W to be processed, the support wafers S, and the overlapping wafers T, are integrally connected.

[0018] The loading / unloading station 2 is provided with a cassette mounting table 10. In the illustrated example, a plurality of cassettes, for example, four cassettes Cw, Cs, and Ct, can be freely mounted on the cassette mounting table 10 in a line in the X-axis direction. Note that the number of cassettes Cw, Cs, and Ct mounted on the cassette mounting table 10 is not limited to that in this embodiment and can be determined arbitrarily.

[0019] The loading / unloading station 2 has a wafer transfer area 20 adjacent to the cassette mounting table 10. The wafer transfer area 20 is provided with a wafer transfer device 22 that is movable on a transfer path 21 extending in the X-axis direction. The wafer transfer device 22 has, for example, two transfer arms 23, 23 that hold and transfer the overlapped wafer T. Each transfer arm 23 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. Note that the configuration of the transfer arm 23 is not limited to this embodiment and may have any configuration.

[0020] In the processing station 3, on the positive side of the Y axis of the wafer transfer area 20, a bonding device 30 that bonds the processing target wafer W and the support wafer S, a modified layer forming device 31 that forms a modified layer inside the processing target wafer W, and a processing device 32 that grinds and processes the processing surface Wg of the processing target wafer W are arranged side by side from the negative side to the positive side of the X axis. Note that the number and arrangement of these bonding devices 30, modified layer forming devices 31, and processing devices 32 are not limited to this embodiment and can be determined arbitrarily. Furthermore, in this embodiment, the processing device 32 functions as the peripheral edge removal device of the present invention.

[0021] The substrate processing system 1 described above is provided with a control device 40. The control device 40 is, for example, a computer, and has a program storage unit (not shown). The program storage unit stores programs for controlling the processing of the target wafer W, support wafer S, and overlapping wafer T in the substrate processing system 1. The program storage unit also stores programs for controlling the operation of drive systems for the various processing devices and transfer devices described above to achieve wafer processing, which will be described later, in the substrate processing system 1. The programs may be recorded on a computer-readable storage medium H, such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magnetic optical disk (MO), or memory card, and installed into the control device 40 from the storage medium H.

[0022] Next, the bonding device 30, the modified layer forming device 31, and the processing device 32 will be described.

[0023] The bonding apparatus 30 bonds the non-processing surface Wn of the processing target wafer W to the bonding surface Sj of the support wafer S by van der Waals forces and hydrogen bonds (intermolecular forces). Preferably, the non-processing surface Wn and the bonding surface Sj are each modified and hydrophilized during this bonding process. Specifically, when modifying the non-processing surface Wn and the bonding surface Sj, oxygen gas or nitrogen gas serving as a processing gas is excited to plasma and ionized, for example, in a reduced-pressure atmosphere. These oxygen ions or nitrogen ions are irradiated onto the non-processing surface Wn and the bonding surface Sj, subjecting them to plasma processing and activation. Furthermore, pure water is supplied to the modified non-processing surface Wn and the bonding surface Sj to hydrophilize them. The bonding apparatus 30 may be configured in any manner, and any known bonding apparatus may be used.

[0024] The modified layer forming apparatus 31 irradiates the inside of the processing target wafer W with laser light to form a modified layer. As shown in FIG. 3, the modified layer forming apparatus 31 has a chuck 100 as a holder that holds the overlapping wafer T with the processing target wafer W on top and the support wafer S on the bottom. The chuck 100 is configured to be movable in the X-axis direction and the Y-axis direction by a moving mechanism 101. The moving mechanism 101 is configured as a general precision XY stage. The chuck 100 is also configured to be rotatable around a vertical axis by a rotating mechanism 102.

[0025] A laser head 103 is provided above the chuck 100 as a modification unit that irradiates the interior of the wafer W with laser light. The laser head 103 irradiates a high-frequency pulsed laser beam generated by a laser beam oscillator (not shown) at a wavelength that is transparent to the wafer W, focusing the laser beam at a predetermined position inside the wafer W. As a result, as shown in FIG. 4, the portion inside the wafer W where the laser beam L is focused is modified, forming a modified layer M. The modified layer M extends in the thickness direction and has a vertically elongated aspect ratio. As shown in FIG. 3, the laser head 103 may be configured to be movable in the X-axis and Y-axis directions by a moving mechanism 104. The moving mechanism 104 is configured as a general precision XY stage. The laser head 103 may also be configured to be movable in the Z-axis direction by a lifting mechanism 105.

[0026] In the modified layer forming apparatus 31, first, the overlapped wafer T is held by the chuck 100, and then the moving mechanism 101 moves the chuck 100 horizontally to center the overlapped wafer T, and the moving mechanism 104 adjusts the position of the laser head 103 so that it is located directly above a predetermined position of the overlapped wafer T (processed wafer W). Thereafter, while the rotation mechanism 102 rotates the chuck 100, the laser head 103 irradiates the interior of the processed wafer W with laser light L, thereby forming an annular modified layer M on the processed wafer W, as shown in FIG. 5. In order to perform the above-mentioned position adjustment, the modified layer forming apparatus 31 may be provided with a camera (not shown) that captures an image of the position of the overlapped wafer T.

[0027] The formation position of this modified layer M on the processing target wafer W will be described in detail. In the substrate processing system 1, the processing surface Wg of the processing target wafer W bonded to the support wafer S is ground, but to avoid the formation of a knife edge on the peripheral edge of the processing target wafer W after grinding, the peripheral edge is removed before grinding. The modified layer M serves as a base point for removing this peripheral edge, and is formed in a ring shape along the boundary between the peripheral edge We and the central portion Wc of the processing target wafer W, as shown in FIG. 5. The peripheral edge We is, for example, in the range of 0.5 mm to 2.0 mm in the radial direction from the edge of the processing target wafer W, and includes the chamfered portion.

[0028] 4, the lower end of the modified layer M is located above the target surface (dotted line in FIG. 4) of the processed wafer W after grinding. That is, the distance H1 between the lower end of the modified layer M and the non-processing surface Wn of the processed wafer W is greater than the target thickness H2 of the processed wafer W after grinding. The distance H1 is arbitrary, but is, for example, 5 μm to 10 μm greater than the target thickness H2. In such a case, the modified layer M does not remain on the processed wafer W after grinding.

[0029] In the modified layer forming apparatus 31 of this embodiment, the chuck 100 is moved horizontally, but the laser head 103 may be moved horizontally, or both the chuck 100 and the laser head 103 may be moved horizontally. Also, although the chuck 100 is rotated, the laser head 103 may be rotated.

[0030] The processing device 32 grinds and processes the processing surface Wg of the processing target wafer W. Specifically, the processing device 32 includes, for example, a grinding unit that grinds the processing surface Wg, a cleaning unit that cleans the processing surface Wg of the processing target wafer W and the non-bonding surface Sn of the support wafer S, and the like.

[0031] 6, the grinding unit 110 has a chuck 111 that holds the overlapping wafer T with the processing target wafer W on the upper side and the support wafer S on the lower side. The chuck 111 is configured to be rotatable around a vertical axis by a rotation mechanism (not shown).

[0032] An annular grinding wheel 112 is provided above the chuck 111. A drive unit 114 is attached to the grinding wheel 112 via a spindle 113. The drive unit 114 incorporates, for example, a motor (not shown), and rotates the grinding wheel 112 while moving it vertically and horizontally.

[0033] In the grinding unit 110, the processing surface Wg of the processing wafer W is ground by rotating the chuck 111 and the grinding wheel 112 while a portion of the arc of the processing wafer W held by the chuck 111 is in contact with the processing wafer W held by the chuck 111.

[0034] Next, a wafer processing performed using the substrate processing system 1 configured as above will be described.

[0035] First, a cassette Cw containing a plurality of wafers W to be processed and a cassette Cs containing a plurality of support wafers S are placed on the cassette placement table 10 of the carry-in / out station 2.

[0036] Next, the wafer W to be processed is removed from the cassette Cw by the wafer transfer device 22 and transferred to the bonding device 30. Subsequently, the support wafer S is also removed from the cassette Cs by the wafer transfer device 22 and transferred to the bonding device 30. In the bonding device 30, the wafer W to be processed is placed on top and the support wafer S is placed on the bottom, and they are bonded together by van der Waals forces and intermolecular forces to form a laminated wafer T. At this time, if the non-processing surface Wn of the wafer W to be processed and the bonding surface Sj of the support wafer S are activated by, for example, plasmatized oxygen ions or nitrogen ions, the van der Waals forces and intermolecular forces are appropriately generated.

[0037] Next, the overlapped wafer T is transferred by the wafer transfer device 22 to the modified layer forming device 31. The overlapped wafer T transferred to the modified layer forming device 31 is handed over to and held by the chuck 100. Thereafter, the moving mechanism 101 moves the chuck 100 horizontally to center the overlapped wafer T, and the position of the laser head 103 is adjusted so that it is positioned directly above a predetermined position on the overlapped wafer T (processed wafer W). This predetermined position is the boundary between the peripheral portion We and the central portion Wc of the processed wafer W. Thereafter, while the rotation mechanism 102 rotates the chuck 100, the laser head 103 irradiates the interior of the processed wafer W with laser light L, thereby forming an annular modified layer M inside the processed wafer W, as shown in FIG. 7(a). The position where this modified layer M is formed is as described above with reference to FIGS. 4 and 5.

[0038] Next, the overlapped wafer T is transferred to the processing device 32 by the wafer transfer device 22. The overlapped wafer T transferred to the processing device 32 is handed over to and held by the chuck 111. Thereafter, as shown in FIG. 7(b), with the processing target wafer W and a portion of the arc of the grinding wheel 112 in contact with each other, the grinding wheel 112 is lowered while the chuck 111 and the grinding wheel 112 are rotated, thereby grinding the processing surface Wg of the processing target wafer W.

[0039] During grinding of the processing surface Wg, cracks C propagate from the modified layer M in the thickness direction inside the processing target wafer W, reaching the processing surface Wg and the non-processing surface Wn. The cracks C propagate in a substantially linear manner because the processing target wafer W has single-crystal silicon. The cracks C are also formed in a ring shape in a plan view. The cracks C may also propagate when the modified layer M is formed in the modified layer forming device 31. In other words, the cracks C may be formed when the processing surface Wg is ground in the processing device 32, or when the modified layer M is formed in the modified layer forming device 31.

[0040] Furthermore, as grinding of the processing surface Wg progresses, the peripheral edge portion We of the processing wafer W is peeled off and removed, starting from the modified layer M and the crack C, as shown in FIG. 7(c). At this time, as described above, the crack C progresses in a substantially linear manner, so the outer surface of the processing wafer W after removal can be made flat with few irregularities. Furthermore, as described above, the lower end of the modified layer M is located above the target surface of the processing wafer W after grinding, so the modified layer M is removed when the processing surface Wg is ground. The modified layer M is amorphous and has weak strength. In this regard, in this embodiment, the modified layer M does not remain on the processing wafer W after grinding, so strong strength can be ensured.

[0041] In this manner, in the modified layer forming device 31, the processing surface Wg of the processing target wafer W is ground to the target thickness while the peripheral edge portion We is removed.

[0042] Thereafter, the overlapped wafer T that has been subjected to all the processes is transferred by the wafer transfer device 22 to the cassette Ct on the cassette mounting table 10. In this way, a series of wafer processes in the substrate processing system 1 is completed.

[0043] Next, a modified example of the first embodiment will be described. In the above, the processing target wafer W and the support wafer S are bonded together in the bonding apparatus 30, and then the modified layer M is formed inside the processing target wafer W in the modified layer forming apparatus 31. However, in this modified example, this order is reversed.

[0044] That is, in the substrate processing system 1, first, the wafer W to be processed is removed from the cassette Cw by the wafer transfer device 22 and transferred to the modified layer forming device 31. In the modified layer forming device 31, a modified layer M is formed at a predetermined position inside the wafer W to be processed, as shown in FIG. 8(a).

[0045] In parallel with the formation of the modified layer M by the modified layer forming device 31 , the support wafer S is removed from the cassette Cs by the wafer transfer device 22 and transferred to the bonding device 30 .

[0046] Next, the processing target wafer W is transferred to the bonding device 30 by the wafer transfer device 22. In the bonding device 30, the processing target wafer W and the support wafer S are bonded together to form an overlapping wafer T, as shown in FIG.

[0047] Next, the overlapped wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, the processing wafer W is brought into contact with a portion of the arc of the grinding wheel 112, and the chuck 111 and the grinding wheel 112 are rotated while the grinding wheel 112 is lowered, thereby grinding the processing surface Wg of the processing wafer W. Then, as shown in FIG. 8(d), the peripheral edge We is removed, and the processing surface Wg of the processing wafer W is ground to a target thickness.

[0048] Thereafter, the overlapped wafer T that has been subjected to all the processes is transferred by the wafer transfer device 22 to the cassette Ct on the cassette mounting table 10. In this way, a series of wafer processes in the substrate processing system 1 is completed.

[0049] According to the first embodiment and the modified example described above, the following effects can be obtained. In the following explanation, the explanation will be made in comparison with the conventional case where the peripheral edge of the wafer to be processed is removed by grinding with a wheel (grinding tool). Note that, conventionally, the peripheral edge of the wafer to be processed is sometimes removed using a blade (grinding tool), but this case also has the same problems as when a wheel is used.

[0050] When the peripheral edge of the wafer to be processed in the laminated wafer is ground off with a wheel after bonding the wafer to be processed and the support wafer, as in the conventional method, i.e., as described in the above-mentioned Patent Document 1, the vertical movement of the wheel may not be properly controlled due to various factors, such as tolerances, and the surface of the support wafer may be ground off. In contrast to this, in this embodiment, by forming a modified layer M inside the processing target wafer W, it is possible to remove the peripheral portion We using the modified layer M and the crack C as starting points. In this case, the bonding surface Sj of the support wafer S is not damaged by grinding or the like.

[0051] When the peripheral edge of the wafer to be processed is ground off with a wheel as in the conventional method before bonding the wafer to the support wafer, particles are generated by the grinding, and there is a risk that these particles will adhere to devices on the wafer to be processed. In contrast, in this embodiment, the peripheral edge portion We is peeled off and removed using the modified layer M and cracks C formed inside the processing target wafer W as starting points, so no particles are generated. Therefore, even when processing is performed on the processing target wafer W before bonding, as in the modified example shown in FIG. 8, devices on the non-processing surface Wn are not contaminated.

[0052] When using a wheel as in the past, there is a limit to how much the wheel can adjust its horizontal position, resulting in variations of a few microns. This results in variations in the width of the peripheral edge (trim width) ground away by the wheel, resulting in poor processing accuracy. In contrast, in this embodiment, a laser is used to form the modified layer M inside the processing target wafer W, ensuring high accuracy of, for example, less than 1 μm. This also improves the accuracy of the width (trim width) of the peripheral edge portion We that is removed using the modified layer M as a base point.

[0053] When a wheel is used as in the conventional method, the peripheral edge is ground by lowering the wheel, and therefore there is a limit to the rotation speed of the chuck that holds the wafer to be processed, and it takes a long time to remove the peripheral edge. In contrast, in this embodiment, a high-frequency laser is used to form a modified layer M inside the processing target wafer W, which allows the rotation speed of the chuck 100 to be increased, thereby enabling processing to be completed in an extremely short time, thereby improving the throughput of wafer processing.

[0054] When wheels are used as in the past, they wear out and need to be replaced periodically. Furthermore, grinding using wheels requires the use of grinding water, which must be treated for wastewater. This increases running costs. In contrast, in this embodiment, the laser head 103 itself does not deteriorate over time, reducing the frequency of maintenance. Also, because it is a dry process using a laser, there is no need to treat grinding water or wastewater. This reduces running costs.

[0055] Furthermore, the semiconductor wafer W to be processed has a notch formed therein to indicate the direction of the crystal orientation, but when removing the peripheral edge We using only a conventional blade, it was difficult to leave the shape of this notch intact. In contrast, in this embodiment, for example, in the modified layer forming device 31, by controlling the relative movement of the processed wafer W and the laser light, the modified layer M can be formed to match the shape of the notch, and the peripheral portion We can also be easily removed while leaving the shape of the notch intact.

[0056] In the above embodiments, methods for efficiently removing the peripheral edge portion We when grinding the processing surface Wg include rotating the grinding wheel 112 from the outside to the inside of the processing target wafer W relative to the rotating processing target wafer W, or rotating the grinding wheel 112 from the inside to the outside of the processing target wafer W relative to the rotating processing target wafer W. In this way, the rotation direction of the grinding wheel 112 can be changed depending on the type of processing target wafer W and the processing step.

[0057] Furthermore, when grinding the processing surface Wg, high-pressure water may be applied to the peripheral edge We from the inside to the outside of the wafer W to efficiently remove (blow away) the peripheral edge We.

[0058] In the above modification of the first embodiment, the modified layer M is formed in the modified layer forming apparatus 31, the processing target wafer W and the support wafer S are bonded in the bonding apparatus 30, and the peripheral portion We is removed in the processing apparatus 32, but the order of wafer bonding and peripheral portion We removal may be reversed. That is, the modified layer M may be formed in the modified layer forming apparatus 31, the peripheral portion We is removed in the processing apparatus 32, and the processing target wafer W and the support wafer S are bonded in the bonding apparatus 30, and the order may be reversed.

[0059] Next, a second embodiment of the present invention will be described. Fig. 9 is a plan view schematically illustrating the configuration of a substrate processing system 200 according to the second embodiment. The substrate processing system 200 has the same configuration as the substrate processing system 1 of the first embodiment, but further includes a peripheral edge removing device 210 in the processing station 3 for removing the peripheral edge We of the wafer W to be processed. The peripheral edge removing device 210 is disposed, for example, between the modified layer forming device 31 and the processing device 32.

[0060] After the modified layer forming device 31 forms a modified layer M on the processing target wafer W, the peripheral edge removing device 210 removes the peripheral edge We by applying a force outward from the modified layer M. That is, in the first embodiment, the peripheral edge We is removed while the processing device 32 is grinding the processing surface Wg of the processing target wafer W, but in the second embodiment, the peripheral edge removing device 210 removes the peripheral edge We.

[0061] 10, the edge removal device 210 has a chuck 211 that holds the overlapped wafer T with the processing target wafer W on the upper side and the support wafer S on the lower side. The chuck 211 is configured to be rotatable around a vertical axis by a rotation mechanism (not shown).

[0062] An annular grinding wheel 212 is provided above the chuck 211. A drive unit 214 is attached to the grinding wheel 212 via a spindle 213. The drive unit 214 has, for example, a built-in motor (not shown), and rotates the grinding wheel 212 while moving it vertically and horizontally. Note that, although the grinding wheel 212 is used in this embodiment, the present invention is not limited to this, and a blade, for example, may also be used.

[0063] In the edge removal device 210, the edge We of the wafer W held by the chuck 211 is brought into contact with part of the arc of the grinding wheel 212, and the chuck 211 and the grinding wheel 212 are rotated to apply an impact to the edge We. The edge We is removed by this impact. In this case, the formation of the modified layer M can improve the accuracy of the removed surface of the wafer W.

[0064] Next, a description will be given of wafer processing performed using the substrate processing system 200 configured as above. Note that in this embodiment, detailed descriptions of processes similar to those in the first embodiment will be omitted.

[0065] First, the wafer W to be processed is removed from the cassette Cw by the wafer transfer device 22 and transferred to the modified layer forming device 31. In the modified layer forming device 31, a modified layer M is formed at a predetermined position inside the wafer W to be processed, as shown in FIG. 11(a).

[0066] In parallel with the formation of the modified layer M by the modified layer forming device 31 , the support wafer S is removed from the cassette Cs by the wafer transfer device 22 and transferred to the bonding device 30 .

[0067] Next, the processing target wafer W is transferred to the bonding device 30 by the wafer transfer device 22. In the bonding device 30, the processing target wafer W and the support wafer S are bonded together to form an overlapping wafer T, as shown in FIG.

[0068] Next, the overlapped wafer T is transported by the wafer transport device 22 to the edge removal device 210. In the edge removal device 210, as shown in FIG. 11(c), a part of the arc of the grinding wheel 212 is brought into contact with the outside of the modified layer M of the processing target wafer W. In this state, when the grinding wheel 212 is lowered and the chuck 211 and the grinding wheel 212 are rotated, an impact is applied to the edge portion We of the processing target wafer W. Due to this impact, the edge portion We is peeled off and removed from the modified layer M and crack C as starting points, as shown in FIG. 11(d).

[0069] Next, the overlapped wafer T is transferred by the wafer transfer device 22 to the processing device 32. In the processing device 32, the processing surface Wg of the processing target wafer W is ground to a target thickness as shown in FIG.

[0070] Thereafter, the overlapped wafer T that has been subjected to all the processes is transferred by the wafer transfer device 22 to the cassette Ct on the cassette mounting table 10. In this way, a series of wafer processes in the substrate processing system 200 is completed.

[0071] In the second embodiment described above, the same effects as in the first embodiment can be obtained.

[0072] 11 in the second embodiment, the formation of the modified layer M, bonding of the processing target wafer W and the support wafer S, removal of the peripheral portion We, and grinding of the processing surface Wg of the processing target wafer W are performed in this order, but the order of the formation of the modified layer M and bonding of the processing target wafer W and the support wafer S may be reversed. In other words, the bonding of the processing target wafer W and the support wafer S, the formation of the modified layer M, removal of the peripheral portion We, and grinding of the processing surface Wg of the processing target wafer W may be performed in this order.

[0073] In the above embodiment, a case has been described in which one processing target wafer W is bonded to a support wafer S, but semiconductor wafers on which devices are formed may be bonded together, or multiple processing target wafers W on which devices are formed may be stacked. In the following explanation, a case in which multiple processing target wafers W on which devices are formed are stacked using the substrate processing system 1 of the first embodiment will be described.

[0074] In the overlapped wafer T subjected to the wafer processing in the first embodiment, the peripheral edge We of the processing target wafer W is removed and the processing surface Wg is ground to the target thickness as shown in Fig. 12(a). In the following description, this first processing target wafer W will be referred to as the first processing target wafer W1.

[0075] This overlapped wafer T is transported to the bonding apparatus 30 by the wafer transport apparatus 22. A wafer W to be processed as a third substrate to be stacked next is also transported to the bonding apparatus 30 by the wafer transport apparatus 22. In the following description, this second wafer W to be processed will be referred to as the second wafer W2 to be processed. Then, in the bonding apparatus 30, the processing surface Wg of the first wafer W1 to be processed and the non-processing surface Wn of the second wafer W2 to be processed are bonded together as shown in FIG. 12(a), thereby forming the overlapped wafer T.

[0076] Next, the overlapped wafer T is transferred by the wafer transfer device 22 to the modified layer forming device 31. In the modified layer forming device 31, a modified layer M is formed at a predetermined position inside the second wafer W2 to be processed, as shown in FIG. 12(b).

[0077] Next, the overlapped wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, with the second processing target wafer W2 and a portion of the arc of the grinding wheel 112 in contact with each other, as shown in Fig. 12(c), the processing surface Wg of the second processing target wafer W2 is ground by lowering the grinding wheel 112 and rotating the chuck 111 and the grinding wheel 112. Then, as shown in Fig. 12(d), the peripheral edge We is removed and the processing surface Wg of the second processing target wafer W2 is ground to a target thickness.

[0078] Thereafter, the overlapped wafer T that has been subjected to all the processes is transferred by the wafer transfer device 22 to the cassette Ct on the cassette mounting table 10. In this way, a series of wafer processes in the substrate processing system 1 is completed.

[0079] Here, when removing the peripheral portion We of the second processed wafer W2 from the overlapped wafer T shown in Figure 12(a) using a wheel as in the conventional method, it is difficult to grind the peripheral portion We because the area below the non-processed surface Wn of the second processed wafer W2 is hollow. In contrast to this, in this embodiment, by forming a modified layer M inside the second wafer to be processed W2, the peripheral edge portion We can be easily removed using the modified layer M and the crack C as starting points.

[0080] Furthermore, when using a wheel or blade as in the past, there is a limit to the horizontal position adjustment of the wheel or blade, resulting in variations of several microns. This results in variations in the width of the peripheral edge (trim width) ground away by the wheel or blade, and these variations accumulate, especially when the wafers to be processed are stacked. This can result in, for example, the wafers to be processed in the upper layer extending beyond the wafers to be processed in the lower layer. In contrast to this, in this embodiment, the modified layer M is formed inside the second wafer W2 to be processed using a laser, so that high precision can be ensured and the wafers W to be processed can be stacked appropriately.

[0081] When multiple processing target wafers W are stacked as in this embodiment, the peripheral edge We of the upper second processing target wafer W2 may be located inside the peripheral edge We of the lower first processing target wafer W1. That is, as shown in FIG. 13(a), the modified layer M inside the second processing target wafer W2 may be formed radially inward from the edge of the first processing target wafer W1. In this case, as shown in FIG. 13(b), the diameter of the second processing target wafer W2 finally stacked will be smaller than the diameter of the first processing target wafer W1. This reliably prevents the second processing target wafer W2 from protruding from the first processing target wafer W1.

[0082] In the modified layer forming apparatus 31 of the above embodiment, as shown in FIG. 4, the modified layer M is formed in one location so that its lower end is positioned above the target surface of the processed wafer W after grinding, but the method of forming the modified layer M is not limited to this.

[0083] As shown in Figures 14(a) to 14(d), a plurality of modified layers M may be formed in the thickness direction of the processing target wafer W. Note that Figure 14 illustrates a device layer and an oxide film formed at the interface between the processing target wafer W and the support wafer S of the overlapped wafer T. That is, a device layer D on which a plurality of devices are formed is formed on the non-processing surface Wn of the processing target wafer W, and an oxide film Fw (e.g., an SiO2 film) is further formed on the device layer D. In addition, an oxide film Fs is also formed on the bonding surface Sj of the support wafer S. Note that when a plurality of devices are formed on the bonding surface Sj of the support wafer S, a device layer (not shown) is formed on the bonding surface Sj in the same manner as the processing target wafer W.

[0084] 14(a), modified layers M1 to M4 are formed in multiple stages, for example, four stages, in the thickness direction of the processing target wafer W. The lower end of the lowermost modified layer M4 is located above the target surface (dotted line in FIG. 14(a)) of the processing target wafer W after grinding. Furthermore, cracks C propagating through these modified layers M1 to M4 reach the processing surface Wg and non-processing surface Wn of the processing target wafer W.

[0085] In the example shown in FIG. 14(b), modified layers M1-M2 are formed in multiple stages, for example, two stages, in the thickness direction of the processing target wafer W. The lower end of the lower modified layer M2 is located above the target surface (dotted line in FIG. 14(b)) of the processing target wafer W after grinding. Furthermore, a crack C propagating through these modified layers M1-M2 reaches the non-processing surface Wn of the processing target wafer W but does not reach the processing surface Wg. In such a case, for example, in the processing device 32, when the grinding wheel 112 is lowered to grind the processing surface Wg, the processing surface Wg is ground including the peripheral portion We of the processing target wafer W until the grinding surface of the grinding wheel 112 reaches the crack C. Then, when the grinding surface of the grinding wheel 112 reaches the crack C, the peripheral portion We below the crack C is peeled off and removed. In this way, by controlling the height of the top end of the crack C extending from the modified layers M1 to M2 to a predetermined position, it is possible to control the size (height) of the small piece of the peripheral edge portion We to be removed.

[0086] In the example shown in FIG. 14(c), modified layers M1 to M4 are formed in multiple stages, for example, four stages, in the thickness direction of the processing target wafer W. The lower end of the bottom modified layer M4 is located below the target surface (dotted line in FIG. 14(c)) of the processing target wafer W after grinding. Furthermore, cracks C propagating through these modified layers M1 to M4 reach the processing surface Wg and the non-processing surface Wn of the processing target wafer W. In this case, since the modified layer M4 is formed at the boundary between the peripheral portion We and the central portion Wc of the processing target wafer W after grinding, the peripheral portion We can be more reliably peeled and removed. Note that when the modified layer M4 is formed below the target surface in this manner, the laser beam is focused by blurring to prevent cracks C from extending from the modified layer M4. This prevents cracks C from being generated in the support wafer S bonded to the processing target wafer W. Although the position of the crack C varies in the entire circumferential direction, the lower end of the modified layer M4 can be controlled in this way, and therefore it can be removed with high precision.

[0087] 14(d), modified layers M1 to M4 are formed in multiple stages, for example, four stages, in the thickness direction of the processing target wafer W. The lower end of the bottommost modified layer M4 is located inside the device layer D. Furthermore, cracks C propagating through these modified layers M1 to M4 reach the processing surface Wg of the processing target wafer W. Even in such a case, since the modified layer M4 is formed at the boundary between the peripheral portion We and the central portion Wc of the processing target wafer W after grinding, the peripheral portion We can be more reliably peeled off and removed.

[0088] As shown in Figure 14, any method can be used to form multiple modified layers M in the thickness direction of the processing target wafer W, but three processing methods can be used, for example, as shown in Figure 15. Figure 15 is a planar development of the portion of the processing target wafer W where the modified layer M is formed (the boundary between the peripheral portion We and the central portion Wc). That is, the horizontal direction in Figure 15 indicates the circumferential direction of the boundary between the peripheral portion We and the central portion Wc, and the vertical direction indicates the thickness direction of the processing target wafer W. Also, dotted lines in Figure 15 indicate modified layers M1 to M4, showing how multiple modified layers M1 to M4 are formed in the thickness direction of the processing target wafer W.

[0089] 15(a), in the modified layer forming apparatus 31, while the chuck 100 is rotated by the rotation mechanism 102, laser light is irradiated from the laser head 103 fixed in the vertical direction onto the inside of the processing target wafer W to form an annular modified layer M4. Next, the rotation of the chuck 100 is stopped, and the irradiation of laser light from the laser head 103 is stopped. Then, the lifting mechanism 105 raises the laser head 103 to a predetermined position, i.e., the position where the modified layer M3 is to be formed. Thereafter, while the chuck 100 is rotated, laser light is irradiated from the laser head 103 to form the annular modified layer M3. The modified layers M2 and M1 are formed in the same manner, thereby forming modified layers M1 to M4 on the processing target wafer W.

[0090] When forming the modified layers M1 to M4, the laser head 103 may be turned on and off while the chuck 100 continues to rotate. For example, while the chuck 100 is rotating, the laser head 103 irradiates the interior of the wafer W with laser light to form the modified layer M4. Then, while the chuck 100 continues to rotate, the laser head 103 temporarily stops irradiating the interior of the wafer W with laser light. The laser head 103 is then raised, and the laser head 103 again irradiates the interior of the wafer W with laser light to form the modified layer M3. By storing the start and end positions of the laser light irradiation when forming the modified layer M4, the start and end positions of the laser light irradiation when forming the next modified layer M3 can be synchronized. By not stopping the rotation of the chuck 100 as described above, the waiting time for laser light irradiation during the acceleration and deceleration of the chuck 100 rotation can be shortened, thereby shortening the overall processing time. Furthermore, by maintaining the rotation speed of the chuck 100 at a constant speed, the laser processing can be performed uniformly, and it is also possible to make the horizontal pitch of the modified layer M uniform.

[0091] In the processing method shown in FIG. 15(b), while the chuck 100 is rotated by the rotation mechanism 102, a laser head 103 fixed in the vertical direction irradiates the interior of the workpiece wafer W with laser light to form an annular modified layer M4. Before the formation of the modified layer M4 is completed, the laser head 103 is raised by the lifting mechanism 105 to a predetermined position, i.e., a position where the modified layer M3 is to be formed, while continuing the rotation of the chuck 100 and the irradiation of the laser light from the laser head 103. Thereafter, while the vertical position of the laser head 103 is fixed, the chuck 100 is rotated and the laser head 103 irradiates the interior with laser light to form the annular modified layer M3. The modified layers M2 and M1 are formed in the same manner, thereby forming modified layers M1 to M4 on the workpiece wafer W. In this case, the modified layers M1 to M4 can be formed continuously, thereby shortening the processing time compared to the processing method shown in FIG. 15(a).

[0092] In the processing method shown in FIG. 15(c), while the chuck 100 is rotated by the rotation mechanism 102 and the laser head 103 is raised by the lifting mechanism 105, the laser head 103 irradiates the interior of the processing target wafer W with laser light, thereby continuously forming annular modified layers M1-M4. That is, in this processing method, the modified layers M1-M4 are continuously formed in a spiral shape. Even in this case, since the modified layers M1-M4 can be continuously formed, the time required for processing can be shortened compared to the processing method shown in FIG. 15(a). Moreover, the modified layers M1-M4 are not formed at a steep gradient in side view, and can be formed more uniformly in the vertical direction (thickness direction of the processing target wafer W) compared to the processing method shown in FIG. 15(b).

[0093] In the above embodiment, the modified layer forming apparatus 31 forms an annular modified layer M inside the processing target wafer W. However, as shown in FIG. 16, a plurality of radially modified layers M' may be further formed, extending radially outward from the annular modified layer M. In such a case, for example, when removing the peripheral edge portion We using the processing apparatus 32, the peripheral edge portion We is peeled off from the annular modified layer M as a base point and divided into a plurality of pieces by the radially modified layers M'. In this way, the peripheral edge portion We to be removed becomes smaller, making it easier to remove.

[0094] Furthermore, as a method of dividing the peripheral portion We (edge ​​chips) to be removed when grinding the processing surface Wg into smaller pieces, multiple annular divided modified layers M" may be formed at any intervals concentrically with the modified layer M, as shown in Figure 16. In such a case, the peripheral portion We to be removed can be made smaller. Furthermore, by controlling the radial intervals between the divided modified layers M", the size of the small pieces of the peripheral portion We to be removed can be controlled.

[0095] Furthermore, when forming multiple annular divided modified layers M" in this manner, the divided modified layers M" may be formed in a spiral shape in a planar view, as shown in Figure 17. In such a case, in the modified layer forming device 31, the chuck 100 or the laser head 103 is moved horizontally while the chuck 100 is rotated and laser light is irradiated from the laser head 103 onto the wafer W to be processed, thereby continuously forming spiral divided modified layers M". As a result, the time required for processing can be shortened.

[0096] 18, the divided modified layer M" may be formed in a spiral and serpentine shape in a plan view. In such a case, in the modified layer forming device 31, the chuck 100 or the laser head 103 is moved horizontally while the chuck 100 is rotated, and laser light is irradiated from the laser head 103 onto the wafer W to be processed. At this time, by controlling the phase, period, and amplitude of the movement of the chuck 100 or the laser head 103, it is possible to form such a serpentine wave-shaped divided modified layer M". Furthermore, this divided modified layer M" is formed two or more times. Then, by controlling the shift in the serpentine phase and the number of times, it is possible to control the size of the small pieces of the peripheral portion We to be removed. In this embodiment, the radial modified layer M' shown in FIGS. 16 and 17 is not necessary.

[0097] 19(a), the divided modified layer M" may be formed so that a crack C developing from the divided modified layer M" extends to a predetermined position inside the wafer W to be processed. That is, the crack C reaches the non-processed surface Wn of the wafer W to be processed, but does not reach the processed surface Wg. In such a case, for example, when the grinding wheel 112 is lowered in the processing device 32 to grind the processed surface Wg, the processed surface Wg is ground including the peripheral portion We of the wafer W to be processed, as shown in FIG. 19(b), until the grinding surface of the grinding wheel 112 reaches the crack C. Then, when the grinding surface of the grinding wheel 112 reaches the crack C, the peripheral portion We is peeled off and removed below the crack C. By controlling the height of the upper end of the crack C to a predetermined position in this way, the size (height) of the small pieces of the peripheral portion We to be removed can be controlled. In the example of Figure 19, the divided modified layer M" is formed in two stages, but by adjusting the focal point from the laser head 103 to two, it is also possible to simultaneously form two stages of divided modified layer M" while rotating the chuck 100.

[0098] In the above-described embodiment, the following method may be used as a method for efficiently removing the peripheral edge We. That is, for example, before bonding the processing target wafer W and the support wafer S in the bonding apparatus 30, the peripheral edge We can be efficiently removed by reducing the bonding force at the interface between the processing target wafer W and the support wafer S in a portion corresponding to the peripheral edge We to be removed. The following method may be considered as a specific example of a method for reducing the bonding force.

[0099] The first bonding strength reduction method is to roughen the non-processed surface Wn of the processing target wafer W, for example, at a portion corresponding to the peripheral edge We to be removed, by irradiating it with laser light or the like. Specifically, an interface processing device 300 shown in Fig. 20 is used. The interface processing device 300 may be provided at any position in the processing station 3 of the substrate processing system 1, for example.

[0100] The interface processing apparatus 300 has a chuck 301 that holds the wafer W to be processed with its non-processing surface Wn facing upward. The chuck 301 is configured to be movable in the X-axis direction and the Y-axis direction by a moving mechanism 302. The moving mechanism 302 is configured as a general precision XY stage. The chuck 301 is also configured to be rotatable around a vertical axis by a rotating mechanism 303.

[0101] A laser head 304 is provided above the chuck 301, and irradiates a non-processing surface Wn at the peripheral edge We of the wafer W with laser light K. The laser head 304 may irradiate any type of laser light K, for example, an excimer laser or a fiber laser. As described above, the device layer D and oxide film Fw are formed on the non-processing surface Wn, and the laser light may have a wavelength that is absorbed by the oxide film Fw, for example, 266 nm. The laser head 304 may be configured to be movable in the X-axis, Y-axis, and Z-axis directions by a movement mechanism (not shown).

[0102] The irradiation port of the laser head 304 for the laser light K is configured to be movable in the horizontal direction by a movement mechanism (not shown). The movement mechanism may, for example, mechanically move the irradiation port of the laser head 304, or may move the irradiation port using an acoustic element. Because the laser light is absorbed by the oxide film Fw, there is no need to strictly control the focal point. For this reason, as in this embodiment, the irradiation port of the laser head 304 is moved by the movement mechanism, and the non-processed surface Wn (oxide film Fw) in the peripheral edge portion We can be modified and roughened.

[0103] A gas supply unit 305 is provided above the chuck 301 to supply gas to the wafer W to be processed. The gas supplied from the gas supply unit 305 may be, for example, clean air or an inert gas such as nitrogen gas. The gas supply unit 305 has a nozzle 306 for supplying gas and a rectifying plate 307 for rectifying the gas supplied from the nozzle 306. The nozzle 306 is connected to a gas supply source (not shown) that stores and supplies gas. The gas supply port of the nozzle 306 is formed above the center of the wafer W to be processed. The rectifying plate 307 is provided approximately parallel to the wafer W to be processed held by the chuck 301 and controls the gas from the nozzle 306 to flow over the non-processing surface Wn of the wafer W to be processed.

[0104] A cup 308 is provided around the chuck 301 to collect and exhaust gas from the gas supply unit 305. An exhaust pipe 309 for exhausting the gas is connected to the bottom surface of the cup 308. The cup 308 may cover the entire periphery of the wafer W to be processed, or may cover only the periphery of the laser head 304 locally.

[0105] In the interface processing apparatus 300, first, the wafer W to be processed is held by a chuck 301, and then the chuck 301 is moved horizontally by a moving mechanism 302 to center the wafer W to be processed. Thereafter, while the chuck 301 is rotated by a rotating mechanism 303, a laser beam K is irradiated from a laser head 304 onto a non-processing surface Wn at the peripheral portion We of the wafer W to roughen the non-processing surface Wn.

[0106] Furthermore, when roughening the non-processing surface Wn, gas is supplied from the gas supply unit 305 to the non-processing surface Wn of the processing target wafer W. The supplied gas flows over the entire non-processing surface Wn and is exhausted through the exhaust pipe 309. When modifying the non-processing surface Wn in the peripheral region We using laser light as in this embodiment, debris (dust) may be generated. If this debris adheres to the non-processing surface Wn in the central region We, the device may be damaged. Therefore, by supplying gas from the gas supply unit 305 and purging, it is possible to prevent debris from adhering to the non-processing surface Wn. Note that after the interface processing in the interface processing device 300, the non-processing surface Wn may be cleaned in a separate cleaning device (not shown). In such a case, compared to a case where, for example, the interface processing device 300 does not have a configuration for supplying gas between the rectifying plate 307 and the processing target wafer W, cleaning in the separate cleaning device can be minimized because cleaning is performed in the interface processing device 300 in this embodiment.

[0107] As shown in FIG. 21 , the unprocessed surface Wn may be roughened by modifying the boundary between the unprocessed surface Wn of the wafer W corresponding to the peripheral edge We to be removed and the unprocessed surface Wn of the wafer W corresponding to the central portion We to be left unremoved, thereby forming a modified groove R1 as a bonding strength reducing portion that reduces the bonding strength. Furthermore, multiple annular modified grooves R2 may be formed outside the modified groove R1. Alternatively, as shown in FIG. 22 , the portion corresponding to the peripheral edge We may be modified in a planar manner to form a roughened modified surface R3. In such a case, the modified surface R3 may be formed by multiple modified grooves R2, or the modified surface R3 may be formed by adjusting the irradiation range of the laser light.

[0108] Next, a description will be given of wafer processing performed using the substrate processing system 1 provided with the above-described interface processing apparatus 300. Note that in this embodiment, detailed description of processing similar to that in the first embodiment will be omitted.

[0109] First, the wafer W to be processed is removed from the cassette Cw by the wafer transfer device 22 and transferred to the interface processing device 300. In the interface processing device 300, the non-processed surface Wn (oxide film Fw) at the peripheral edge We of the wafer W to be processed is modified to form either roughened modified grooves R1, R2 or a modified surface R3, as shown in FIG.

[0110] In parallel with the roughening of the non-processed surface Wn in the interface processing device 300 , the support wafer S in the cassette Cs is taken out by the wafer transfer device 22 and transferred to the bonding device 30 .

[0111] Next, the processing target wafer W is transferred to the bonding device 30 by the wafer transfer device 22. At this time, the processing target wafer W is turned over by the wafer transfer device 22 or an inverting device (not shown). In the bonding device 30, the processing target wafer W and the support wafer S are bonded together to form an overlapped wafer T, as shown in FIG. 23(b).

[0112] Next, the overlapped wafer T is transferred by the wafer transfer device 22 to the modified layer forming device 31. In the modified layer forming device 31, a modified layer M is formed at a predetermined position inside the processing target wafer W, as shown in Fig. 23(c). That is, the modified layer M is formed corresponding to the modified grooves R1, R2 and modified surface R3.

[0113] Next, the overlapped wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, the processing surface Wg of the processing target wafer W is ground to a target thickness, as shown in FIG. 23(d). As the grinding of the processing surface Wg progresses, the peripheral edge portion We of the processing target wafer W is peeled off and removed from the modified layer M and crack C as shown in FIG. 23(e). At this time, the interface (non-processing surface Wn) between the processing target wafer W and the support wafer S is roughened and the bonding strength is reduced, so that the peripheral edge portion We can be properly removed.

[0114] Thereafter, the overlapped wafer T that has been subjected to all the processes is transferred by the wafer transfer device 22 to the cassette Ct on the cassette mounting table 10. In this way, a series of wafer processes in the substrate processing system 1 is completed.

[0115] In this embodiment, after forming the modified grooves R1, R2, or the modified surface R3 in the processing target wafer W as shown in FIG. 23(a), the processing target wafer W and the support wafer S are bonded together as shown in FIG. 23(b), and then the modified layer M is formed on the processing target wafer W as shown in FIG. 23(c). However, the order of these steps is not limited. For example, the modified grooves R1, R2, and the modified surface R3 may be formed, the modified layer M may be formed, and the wafers W and S may be bonded together in this order. Also, the modified layer M may be formed, the modified grooves R1, R2, and the modified surface R3 may be formed, and the wafers W and S may be bonded together in this order. Furthermore, the modified layer M may be formed, the wafers W and S may be bonded together in this order.

[0116] In this embodiment, the interface treatment device 300 is provided separately from the modified layer forming device 31, but the interface treatment device 300 and the modified layer forming device 31 may be the same device. In such a case, for example, a laser head 304 is provided in the modified layer forming device 31.

[0117] Alternatively, a protective film may be formed on the non-processing surface Wn prior to laser processing in the interface processing apparatus 300. In such a case, the processing station 3 of the substrate processing system 1 is provided with a coating device (not shown) that forms the protective film and a cleaning device (not shown) that cleans the protective film. The coating device applies a protective material to the entire surface of the non-processing surface Wn by, for example, spin coating, to form the protective film. The cleaning device supplies a cleaning liquid to the entire surface of the non-processing surface Wn by, for example, spin cleaning, to clean and remove the protective film.

[0118] In the substrate processing system 1, first, a protective film is formed on the entire non-processing surface Wn in the coating device. Then, in the interface processing device 300, the non-processing surface Wn at the peripheral edge We is modified as shown in FIG. 23(a). At this time, because the protective film is formed on the central portion Wc of the processing target wafer W, damage to the device can be suppressed even if debris is generated by the laser light. Then, once the protective film on the non-processing surface Wn is cleaned and removed in the cleaning device, the processing target wafer W and the support wafer S can be bonded as shown in FIG. 23(b).

[0119] The second bonding strength reduction method is to form a release film by applying a release agent to the non-processed surface Wn of the wafer W, for example, in a portion corresponding to the peripheral edge We to be removed. Specifically, for example, an interface processing device 310 shown in FIG. 24 is used. The interface processing device 310 may be provided at any position in the processing station 3 of the substrate processing system 1.

[0120] The interface processing apparatus 310 has a chuck 311 that holds the wafer W to be processed with the non-processing surface Wn facing upward. The chuck 311 is configured to be rotatable around a vertical axis by a rotation mechanism 312.

[0121] A nozzle 313 is provided above the chuck 311 to apply a release agent A to the non-processing surface Wn of the peripheral edge We of the wafer W to be processed. The nozzle 313 is connected to a release agent supply source (not shown) that stores and supplies the release agent A. The nozzle 313 may be configured to be movable in the X-axis, Y-axis, and Z-axis directions by a movement mechanism (not shown). The release agent A may be made of any material that reduces the bonding strength at the interface between the wafer W to be processed and the support wafer S.

[0122] The wafer processing method performed using the substrate processing system 1 equipped with the above-described interface processing device 310 is the same as the method shown in Fig. 23, except that the laser processing in the interface processing device 300 is replaced with a release agent application process in the interface processing device 310. In the interface processing device 310, a release agent A is applied from a nozzle 313 to the non-processing surface Wn of the peripheral edge We while the chuck 311 is rotating, thereby forming a release film on the non-processing surface Wn. Then, the release film reduces the bonding strength between the processed wafer W and the support wafer S at the peripheral edge We, so that the peripheral edge We can be appropriately removed as shown in Fig. 23(e).

[0123] When the rotation speed of the chuck 311 in the interface processing device 310 is high, the applied release agent A is thrown off to the outside of the wafer W by centrifugal force. On the other hand, when the rotation speed of the chuck 311 is medium, there is a risk that the release agent A will get around to the processing surface Wg of the wafer W. Therefore, a rinse liquid of the release agent A may be supplied from the processing surface Wg side. When the rotation speed of the chuck 311 is low, the release agent A may be sucked and discharged from the outside of the wafer W.

[0124] The third method for reducing the bonding strength is to thinly etch the non-processed surface Wn of the wafer W, which corresponds to the peripheral edge We to be removed, using a chemical solution. For example, in the case of a TEOS film, etching is performed using hydrofluoric acid. The interface processing device for this etching can be configured as desired, and any known etching device can be used.

[0125] In this embodiment, instead of the laser processing by the interface processing apparatus 300 shown in FIG. 23(a), an etching process is performed on the peripheral edge portion We. The etched peripheral edge portion We is removed, forming a step between the peripheral edge portion We and the central portion Wc, or the etched peripheral edge portion We is roughened. As a result, when the processing target wafer W and the support wafer S are bonded in the bonding apparatus 30 as shown in FIG. 23(b), the processing target wafer W and the support wafer S are not bonded at the peripheral edge portion We. Therefore, the peripheral edge portion We can be appropriately removed as shown in FIG. 23(e).

[0126] A fourth method for reducing bonding strength is to irradiate the non-processed surface Wn of the wafer W, which corresponds to the peripheral edge We to be removed, with plasma during bonding, for example, when the bonding apparatus 30 is a plasma-based bonding apparatus as described above. As described above, in the bonding apparatus 30, plasma-converted oxygen ions or nitrogen ions are irradiated onto the non-processed surface Wn, thereby plasma-processing and activating the non-processed surface Wn. Therefore, in this bonding apparatus 30, a shielding plate may be provided above the non-processed surface Wn of the peripheral edge We to prevent the non-processed surface Wn from being irradiated with oxygen ions or nitrogen ions.

[0127] In this case, in the bonding apparatus 30, the non-processed surface Wn at the central portion Wc of the processing target wafer W is activated by oxygen ions or nitrogen ions, but the non-processed surface Wn at the peripheral portion We is not activated. As a result, when the processing target wafer W and the support wafer S are bonded together in the bonding apparatus 30 as shown in Figure 23(b), the processing target wafer W and the support wafer S are not bonded together at the peripheral portion We. For this reason, the peripheral portion We can be appropriately removed as shown in Figure 23(e).

[0128] In the above embodiment, the four processes described above were performed on the non-processed surface Wn of the processing wafer W before bonding to reduce the bonding force, but similar processes may also be performed on the bonding surface Sj of the support wafer S.

[0129] In the above-described embodiment, the peripheral edge We can be efficiently removed by bonding the processing target wafer W and the support wafer S using the bonding device 30, and then reducing the bonding force at the interface between the processing target wafer W and the support wafer S in a portion corresponding to the peripheral edge We to be removed. The following method can be considered as a specific example of a method for reducing the bonding force.

[0130] For example, laser light is transmitted to the non-processing surface Wn of the wafer W to be processed, causing ablation at each interface. Specifically, for example, a processing device 320 shown in Fig. 25 is used. The processing device 320 is provided, for example, in the processing station 3 of the substrate processing system 1, in place of the modified layer forming device 31.

[0131] The processing device 320 further includes a laser head 321, a moving mechanism 322, and an elevating mechanism 323 in the configuration of the modified layer forming device 31. The laser head 321 irradiates the non-processing surface Wn with laser light to modify it. The laser head 321 irradiates the non-processing surface Wn with high-frequency pulsed laser light oscillated from a laser light oscillator (not shown), the laser light having a wavelength that is transparent to the processing target wafer W, and focuses the laser light at a predetermined position inside the processing target wafer W. This modifies the portion inside the processing target wafer W where the laser light is focused. The moving mechanism 322 moves the laser head 321 in the X-axis and Y-axis directions. The moving mechanism 322 is configured with a general precision XY stage. The elevating mechanism 323 moves the laser head 321 in the Z-axis direction. As described above, the processing device 320 serves as both a modified layer forming device and an interface processing device.

[0132] When the processing apparatus 320 processes the interface between the processing target wafer W and the support wafer S, it modifies the inside of the processing target wafer W or the inside of the device layer D. That is, the interface in this embodiment includes the inside of the processing target wafer W and the inside of the device layer D.

[0133] When modifying the inside of the processing target wafer W as shown in FIG. 26, a modified surface R4 is formed near the non-processed surface Wn in the peripheral edge portion We (outside the modified layer M). In this processing method, as shown in FIG. 27, laser light L is irradiated from the laser head 321 toward the inside of the processing target wafer W. The laser light L passes through the inside of the processing target wafer W and is condensed, and the condensed portion is modified. Then, while rotating the chuck 100 with the rotation mechanism 102 and moving the laser head 321 radially outward with the movement mechanism 322, the laser head 321 irradiates the inside of the processing target wafer W with the laser light L. This forms the modified surface R4. Note that when forming the modified surface R4, the chuck 100 may be moved radially by the movement mechanism 101, or both the laser head 321 and the chuck 100 may be moved.

[0134] When forming the modified surface R4 inside the processing target wafer W in this manner, after removing the peripheral edge portion We, a part of the processing target wafer W remains on the support wafer S. Therefore, after removing the peripheral edge portion We, this remaining part of the processing target wafer W may be removed by etching.

[0135] 28, when the inside of the device layer D is modified, a modified surface R5 is formed in the peripheral portion We (outside the modified layer M) inside the device layer D. There are three processing methods for this, as shown in FIG.

[0136] In the first processing method, as shown in FIG. 29( a), the focal point of the laser light L from the laser head 321 is positioned above the device layer D inside the wafer W to be processed. In this case, the energy of the laser light L is reduced to a level where the wafer W is not modified even when the laser light L is focused. In this case, the laser light L is focused once inside the wafer W to be processed, but the defocused and expanded laser light L passes through the wafer W to be irradiated onto the device layer D. The laser light L is absorbed by the device layer D, causing ablation of the device layer D. Then, the chuck 100 is rotated by the rotation mechanism 102, and the laser head 321 is moved radially outward by the movement mechanism 322, while the laser head 321 is irradiated with the laser light L. As a result, a modified surface R5 is formed on the device layer D. When forming the modified surface R5, the chuck 100 may be moved in the radial direction by the moving mechanism 101, or both the laser head 321 and the chuck 100 may be moved.

[0137] The second processing method is a method in which the focal point of laser light L from the laser head 321 is positioned inside the device layer D, as shown in FIG. 29(b). In this case, the laser light L passes through the wafer W to be processed and is irradiated onto the device layer D, causing ablation of the device layer D. Then, the laser head 321 irradiates the device layer D with the laser light L while rotating the chuck 100 with the rotation mechanism 102 and moving the laser head 321 radially outward with the movement mechanism 322. This forms a modified surface R5 on the device layer D. Note that when forming the modified surface R5, the chuck 100 may be moved radially by the movement mechanism 101, or both the laser head 321 and the chuck 100 may be moved.

[0138] The third processing method is a method in which the focal point of the laser light L from the laser head 321 is positioned below the device layer D, as shown in FIG. 29(c). In this case, the laser light L passes through the wafer W to be processed and is irradiated onto the device layer D, causing ablation of the device layer D. Since the laser light L is absorbed by the device layer D, it is not focused below the device layer D. Then, the laser head 321 irradiates the device layer D while rotating the chuck 100 with the rotation mechanism 102 and moving the laser head 321 radially outward with the movement mechanism 322. This forms a modified surface R5 on the device layer D. When forming the modified surface R5, the chuck 100 may be moved radially by the movement mechanism 101, or both the laser head 321 and the chuck 100 may be moved.

[0139] When forming the modified surface R5 on the device layer D, the effects of ablation in the peripheral portion We of the device layer D may extend to the central portion Wc of the device layer D inside. Therefore, as shown in Figure 14(d), it is preferable to form the modified surface R5 after forming the modified layer M4 on the device layer D. In such a case, the modified layer M4 serves to block the effects of ablation, thereby reliably preventing the effects of ablation from extending to the central portion Wc.

[0140] Next, a description will be given of wafer processing performed using the substrate processing system 1 provided with the above processing device 320. Note that in this embodiment, detailed description of processing similar to that in the first embodiment will be omitted.

[0141] First, the wafer W to be processed is removed from the cassette Cw by the wafer transfer device 22 and transferred to the bonding device 30. Subsequently, the support wafer S is also removed from the cassette Cs by the wafer transfer device 22 and transferred to the bonding device 30. In the bonding device 30, the wafer W to be processed and the support wafer S are bonded together to form an overlapped wafer T, as shown in FIG. 30(a).

[0142] Next, the overlapped wafer T is transferred to the processing device 320 by the wafer transfer device 22. In the processing device 320, the laser head 103 is moved above the peripheral edge portion We. Then, while the chuck 100 is being rotated, the laser head 103 irradiates the inside of the processing target wafer W with laser light, and a modified layer M is formed at a predetermined position inside the processing target wafer W, as shown in FIG. 30(b).

[0143] Next, in the processing device 320, the laser head 103 is retracted and the laser head 321 is moved above the peripheral edge We. Then, while rotating the chuck 100, the laser head 321 is moved radially outward, and laser light is irradiated from the laser head 321. As a result, a modified surface R4 or R5 is formed inside the processed wafer W or on the device layer D, respectively, as shown in FIG. 30(c).

[0144] The order of forming the modified layer M shown in FIG. 30(b) and the forming of the modified surface R4 or R5 shown in FIG. 30(c) may be reversed.

[0145] Next, the overlapped wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, the processing surface Wg of the processing target wafer W is ground to a target thickness, as shown in FIG. 30(d). As the grinding of the processing surface Wg progresses, the peripheral portion We of the processing target wafer W is peeled off and removed from the modified layer M and crack C as shown in FIG. 30(e). At this time, a modified surface R4 or R5 is formed at the interface between the processing target wafer W and the support wafer S, reducing the bonding strength, and therefore the peripheral portion We can be appropriately removed.

[0146] Thereafter, the overlapped wafer T that has been subjected to all the processes is transferred by the wafer transfer device 22 to the cassette Ct on the cassette mounting table 10. In this way, a series of wafer processes in the substrate processing system 1 is completed.

[0147] This embodiment also provides the same effects as those of the first and second embodiments. Moreover, in the processing apparatus 320, the modified layer M and the modified surface R4 or R5 are formed using the same chuck 100, so the processed wafer W is not decentered during processing by the laser head 103 and processing by the laser head 321. As a result, the position of the modified layer M can be aligned with the inner peripheral position of the modified surface R4 or R5, allowing the peripheral edge portion We to be more appropriately removed.

[0148] In the processing device 320, the laser head 103 and the laser head 321 do not need to be provided separately and may be a common head. Also, the laser head 103 and the laser head 321 in the processing device 320 may be provided in different devices, or may be provided in the modified layer forming device 31 and the interface processing device, respectively.

[0149] 12, this embodiment can also be applied to the case where a second processing target wafer W2 is further stacked on the overlapped wafer T. In this case, if the position of the peripheral edge portion We to be removed in the second processing target wafer W2 coincides with the position of the overlapped wafer T, the formation of the modified surface R4 or R5 can be omitted.

[0150] This embodiment can also be applied to a case where the peripheral edge We to be removed from the upper second processed wafer W2 is located inside the peripheral edge We to be removed from the lower first processed wafer W1, as shown in Fig. 13. In this case, however, it is preferable that the modified surface R4 or R5 is formed on the peripheral edge We of the second processed wafer W2 to be removed from the first processed wafer W1.

[0151] In the above embodiments, it is preferable that the position of the modified groove R1 formed on the processed wafer W before bonding, the inner peripheral position of the modified surface R3, or the inner peripheral positions of the modified surfaces R4 and R5 formed on the processed wafer W after bonding all coincide with the position of the modified layer M.

[0152] 31 shows an example in which the processing target wafer W is eccentrically bonded to the overlapping wafer T, causing the position of the modified layer M to be misaligned with the inner peripheral position of the modified surface R4. In this case, as shown in FIG. 31, there are locations in which the modified layer M is located radially inward from the inner peripheral position of the modified surface R4, and locations in which the modified layer M is located radially outward from the inner peripheral position of the modified surface R4.

[0153] 32(a), when the modified layer M is located radially inward from the inner periphery of the modified surface R4, as shown in FIG. 32(b), when the processing surface Wg of the processing target wafer W is ground to remove the peripheral edge portion We, the width D1 of the removed peripheral edge portion may be smaller than the target width D2 of the peripheral edge portion We to be removed. Furthermore, because the removed peripheral edge portion peels off from the modified layer M without passing through the crack C, the outer surface of the processing target wafer W may become rough after the peripheral edge portion is removed.

[0154] Furthermore, even if the modified layer M is located radially inward from the inner circumference of the modified surface R4, if the distance between the modified layer M and the inner circumference of the modified surface R4 is sufficiently small, the bonding force between the processed wafer W and the support wafer S becomes sufficiently small, so that the peripheral portion We can be removed.

[0155] 33(a), when the modified layer M is located radially outward from the inner periphery of the modified surface R4, as shown in FIG. 33(b), when the processed surface Wg of the processed wafer W is ground to remove the peripheral portion We, the modified surface R4 remains between the processed wafer W and the device layer D. In the area where this modified surface R4 is present, the processed wafer W and the device layer D may peel off, which may cause chipping.

[0156] There are two possible methods for eliminating this misalignment between the position of the modified layer M and the inner peripheral position of the modified surface R4. The first method for eliminating the misalignment is to detect the eccentricity of the processed wafer W in the overlapped wafer T, and adjust the position of the modified layer M or the inner peripheral position of the modified surface R4 based on the detection results. The second method for eliminating the misalignment is to detect the position of the modified layer M or the inner peripheral position of the modified surface R4, and adjust the position of the modified surface R4 or the modified layer M formed in subsequent processing based on the detection results.

[0157] When performing the above-described two misalignment elimination methods, for example, a processing device 330 shown in Fig. 34 is used. The processing device 330 is provided, for example, in the processing station 3 of the substrate processing system 1 in place of the processing device 320. The processing device 330 has the same configuration as the processing device 320, but has an eccentricity detection unit 331 for performing the first misalignment elimination method and a position detection unit 332 for performing the second misalignment elimination method.

[0158] The first method for eliminating misalignment will be described. The eccentricity detection unit 331 is disposed above the center of the chuck 100. The eccentricity detection unit 331 is configured to be movable in the X-, Y-, and Z-axis directions by a moving mechanism (not shown). The eccentricity detection unit 331 has, for example, a CCD camera. The eccentricity detection unit 331 captures images of the overlapped wafer T held by the chuck 100, specifically at least three points on the outer periphery. The eccentricity detection unit 331 then detects the misalignment of the center of the processing target wafer W relative to the center of rotation of the chuck 100, i.e., the eccentricity of the processing target wafer W in the overlapped wafer T. The configuration of the eccentricity detection unit 331 is not limited to this embodiment and may have, for example, an IR camera. In such a case, the eccentricity detection unit 331 captures images of alignment marks formed on the processing target wafer W, for example, to detect the eccentricity of the processing target wafer W in the overlapped wafer T.

[0159] The first method for eliminating the misalignment is performed using the detection result of the eccentricity detection unit 331. Here, a description will be given of a case where the wafer processing shown in FIG.

[0160] First, in the bonding apparatus 30, the processing target wafer W and the support wafer S are bonded together as shown in FIG. 30(a) to form an overlapped wafer T. Next, the overlapped wafer T is transferred to the processing apparatus 330. In the processing apparatus 330, the overlapped wafer T is held by the chuck 100, and then an image of the overlapped wafer T is taken by the eccentricity detection unit 331, and the eccentricity of the processing target wafer W in the overlapped wafer T is detected. The detection result of the eccentricity detection unit 331 is output to the control apparatus 40.

[0161] The control device 40 adjusts the central axis of the chuck 100, the irradiation axis of the laser light irradiated from the laser head 103, or the irradiation axis of the laser light irradiated from the laser head 321 based on the detection result of the eccentricity detection unit 331, i.e., the eccentricity of the wafer W to be processed. By adjusting the central axis of the chuck 100 or the irradiation axis of the laser head 103, it is possible to appropriately form a modified layer M on the wafer W to be processed, as shown in FIG. 30(b). Furthermore, by adjusting the central axis of the chuck 100 or the irradiation axis of the laser head 321, it is possible to appropriately form a modified surface R4 on the wafer W to be processed, as shown in FIG. 30(c).

[0162] As described above, by adjusting the central axis of the chuck 100, the irradiation axis of the laser head 103, or the irradiation axis of the laser head 321 based on the detection results of the eccentricity of the processed wafer W by the eccentricity detection unit 331, the position of the modified layer M can be aligned with the inner peripheral position of the modified surface R4.

[0163] The eccentricity detection unit 331 may be provided in an eccentricity detection device (not shown) outside the processing device 320. In such a case, when the overlapped wafer T is transferred from the eccentricity detection device to the processing device 320 by the wafer transfer device 22, the overlapped wafer T is transferred so that the center of the processing target wafer W and the center of the chuck 100 coincide with each other, based on the detection result of the eccentricity of the processing target wafer W by the eccentricity detection unit 331. In this way, the modified layer M can be appropriately formed on the processing target wafer W as shown in FIG. 30(b), and the modified surface R4 can be appropriately formed inside the processing target wafer W or in the device layer as shown in FIG. 30(c). Therefore, the position of the modified layer M can be aligned with the inner peripheral position of the modified surface R4.

[0164] Furthermore, the eccentricity detection unit 331 may detect the eccentricity of a second processing target wafer W2 that is further stacked and bonded to the overlapped wafer T. Even in such a case, the position of the modified layer M can be aligned with the inner peripheral position of the modified surface R4 based on the detection result of the eccentricity of the second processing target wafer W2 with respect to the overlapped wafer T.

[0165] The second method for eliminating misalignment will be described. The position detection unit 332 is disposed above the outer periphery of the chuck 100. The position detection unit 332 is configured to be movable in the X-axis, Y-axis, and Z-axis directions by a movement mechanism (not shown). The position detection unit 332 is, for example, an IR camera using infrared rays. The position detection unit 332 detects the position of the modified layer M formed on the processing target wafer W or the inner peripheral position of the modified surface R4 for the overlapped wafer T held by the chuck 100.

[0166] The second method for eliminating the misalignment is performed using the detection result of the position detection unit 332. Here, a description will be given of the case where the wafer processing shown in FIG.

[0167] First, in the bonding apparatus 30, the processing target wafer W and the support wafer S are bonded as shown in Fig. 30(a) to form an overlapped wafer T. Next, the overlapped wafer T is transferred to the processing apparatus 330. In the processing apparatus 330, a modified layer M is formed on the processing target wafer W using the laser head 103 as shown in Fig. 30(b).

[0168] When a modified layer M is formed on the processing target wafer W, the position detection unit 332 uses infrared rays to capture an image of the modified layer M inside the processing target wafer W and detects the position of the modified layer M. The detection result of the position detection unit 332 is output to the control device 40.

[0169] The control device 40 adjusts the central axis of the chuck 100 or the irradiation axis of the laser head 321 based on the detection result of the position detection unit 332, i.e., the position of the modified layer M. This makes it possible to properly form a modified surface R4 on the processing target wafer W, as shown in Figure 30(c). As a result, it is possible to align the position of the modified layer M with the inner peripheral position of the modified surface R4.

[0170] 30(b) and the modified surface R4 shown in FIG. 30(c) may be formed in the reverse order. In such a case, after the modified surface R4 is formed on the processing target wafer W, the position detection unit 332 captures an image of the modified surface R4 using infrared rays, and detects the inner peripheral position of the modified surface R4. The detection result of the position detection unit 332 is output to the control device 40.

[0171] The control device 40 adjusts the central axis of the chuck 100 or the irradiation axis of the laser head 103 based on the detection result of the position detection unit 332, i.e., the inner peripheral position of the modified surface R4. This allows the modified layer M to be appropriately formed on the processing target wafer W. As a result, the position of the modified layer M can be aligned with the inner peripheral position of the modified surface R4.

[0172] Furthermore, in the above embodiment, the position detection unit 332 detects the position of the modified layer M or the inner peripheral position of the modified surface R4 formed on the processing target wafer W after bonding, but it may also detect the position of the modified layer M or the inner peripheral position of the modified surface R4 formed on the processing target wafer W before bonding. Even in such a case, after detection by the position detection unit 332, the modified surface R4 or the modified layer M can be appropriately formed so that the position of the modified layer M and the inner peripheral position of the modified surface R4 coincide with each other.

[0173] In short, regardless of whether the formation of the modified layer M or the formation of the modified surface R4 is performed first, the position of the modified layer M or the inner position of the modified surface R4 can be detected by the position detection unit 332, and the modified surface R4 or the modified layer M can then be formed appropriately, and the position of the modified layer M can be aligned with the inner position of the modified surface R4.

[0174] Next, a substrate processing system according to a third embodiment of the present invention will be described below. Fig. 35 is a plan view schematically showing the outline of the configuration of a substrate processing system 400 according to the third embodiment.

[0175] The substrate processing system 400 has a configuration in which, for example, a loading / unloading station 401 through which a cassette Ct capable of accommodating multiple overlapping wafers T is loaded and unloaded from the outside, and a processing station 402 equipped with various processing devices that perform predetermined processing on the overlapping wafers T are integrally connected.

[0176] The loading / unloading station 401 is provided with a cassette mounting table 410. In the illustrated example, a plurality of cassettes Ct, for example, four cassettes Ct, can be freely mounted on the cassette mounting table 410 in a line in the Y-axis direction. Note that the number of cassettes Ct mounted on the cassette mounting table 410 is not limited to that in this embodiment and can be determined arbitrarily.

[0177] The loading / unloading station 401 has a wafer transfer area 420 adjacent to the cassette mounting table 410. The wafer transfer area 420 has a wafer transfer device 422 that is movable on a transfer path 421 extending in the Y-axis direction. The wafer transfer device 422 has, for example, two transfer arms 423, 423 that hold and transfer the overlapped wafer T. Each transfer arm 423 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. Note that the configuration of the transfer arm 423 is not limited to this embodiment and may have any configuration.

[0178] The processing station 402 is provided with a wafer transfer area 430. The wafer transfer area 430 is provided with a wafer transfer device 432 that is movable on a transfer path 431 extending in the X-axis direction. The wafer transfer device 432 is configured to be able to transfer the overlapped wafer T to a transition device 434, wet etching devices 440 and 441, and a processing device 450, which will be described later. The wafer transfer device 432 also has, for example, two transfer arms 433, 433 that hold and transfer the overlapped wafer T. Each transfer arm 433 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The configuration of the transfer arm 433 is not limited to that of this embodiment, and any configuration may be used.

[0179] Between the wafer transfer area 420 and the wafer transfer area 430, a transition device 434 for transferring the overlapped wafer T is provided.

[0180] On the Y-axis positive side of wafer transfer area 430, wet etching devices 440 and 441 are arranged in this order in the X-axis direction from the loading / unloading station 401 side. In the wet etching devices 440 and 441, wet etching is performed on the processing surface Wg of the wafer W to be processed using a chemical solution such as hydrofluoric acid.

[0181] A processing device 450 is disposed on the positive X-axis side of the wafer transfer region 430. In the processing device 450, processing processes such as grinding and cleaning are performed on the processing target wafer W. The processing device 450 has a rotary table 460, a transfer unit 470, a processing unit 480, a first cleaning unit 490, a second cleaning unit 500, a rough grinding unit 510, a medium grinding unit 520, and a finish grinding unit 530.

[0182] The turntable 460 is configured to be freely rotatable by a rotation mechanism (not shown). Four chucks 461 that suction-hold the overlapped wafer T are provided on the turntable 460. The chucks 461 are arranged evenly on the same circumference as the turntable 460, i.e., at 90-degree intervals. The four chucks 461 can be moved to a delivery position A0 and processing positions A1 to A3 by the rotation of the turntable 460. Furthermore, each of the four chucks 461 is configured to be rotatable around a vertical axis by a rotation mechanism (not shown).

[0183] In this embodiment, the transfer position A0 is located on the negative X-axis and negative Y-axis sides of the turntable 460, and the second cleaning unit 500, the processing unit 480, and the first cleaning unit 490 are arranged side by side on the negative X-axis side of the transfer position A0. The processing unit 480 and the first cleaning unit 490 are arranged stacked in this order from above. The first processing position A1 is located on the positive X-axis and negative Y-axis sides of the turntable 460, and a rough grinding unit 510 is arranged there. The second processing position A2 is located on the positive X-axis and positive Y-axis sides of the turntable 460, and a medium grinding unit 520 is arranged there. The third processing position A3 is located on the negative X-axis and positive Y-axis sides of the turntable 460, and a finish grinding unit 530 is arranged there.

[0184] The transfer unit 470 is an articulated robot equipped with multiple, for example, three, arms 471. Each of the three arms 471 is configured to be freely rotatable. A transfer pad 472 that suction-holds the overlapped wafer T is attached to the arm 471 at the tip end. The arm 471 at the base end is attached to a movement mechanism 473 that moves the arm 471 in the vertical direction. The transfer unit 470 having such a configuration can transfer the overlapped wafer T to the delivery position A0, the processing unit 480, the first cleaning unit 490, and the second cleaning unit 500.

[0185] In the processing unit 480, the horizontal orientation of the overlapped wafer T before the grinding process is adjusted. For example, while rotating the overlapped wafer T held by the chuck 100, a detection unit (not shown) detects the position of the notch portion of the wafer W to be processed, and thereby adjusts the position of the notch portion to adjust the horizontal orientation of the overlapped wafer T.

[0186] The processing unit 480 has the same configuration as the processing device 320, namely, a chuck 100, a moving mechanism 101, a rotating mechanism 102, a laser head 103, a moving mechanism 104, a lifting mechanism 105, a laser head 321, a moving mechanism 322, and a lifting mechanism 323. In the processing unit 480, the laser head 103 forms a modified layer M on the processing target wafer W, and the laser head 321 forms a modified surface R4 or R5 on the processing target wafer W. If the processing target wafer W has a modified layer M formed thereon in advance, the processing unit 480 forms only the modified surface R4 or R5. Conversely, if the processing target wafer W has a modified surface R4 or R5 formed thereon in advance, the processing unit 480 forms only the modified layer M.

[0187] In the first cleaning unit 490, the processing surface Wg of the processing target wafer W after the grinding process is cleaned, more specifically, spin-cleaned. For example, while the overlapped wafer T held on a spin chuck (not shown) is being rotated, a cleaning liquid is supplied to the processing surface Wg from a cleaning liquid nozzle (not shown). The supplied cleaning liquid then spreads over the processing surface Wg, cleaning the processing surface Wg.

[0188] In the second cleaning unit 500, the non-bonding surface Sn of the support wafer S in a state in which the processed wafer W after the grinding process is held on the transfer pad 472 is cleaned, and the transfer pad 472 is also cleaned.

[0189] The rough grinding unit 510 roughly grinds the processing surface Wg of the wafer W to be processed. The rough grinding unit 510 has a rough grinding part 511. The rough grinding part 511 has the grinding wheel 112, the spindle 113, and the drive part 114 shown in FIG. 6. The rough grinding part 511 is configured to be movable in the vertical and horizontal directions along the support 512.

[0190] The medium grinding unit 520 performs medium grinding on the processing surface Wg of the wafer W to be processed. The medium grinding unit 520 has a medium grinding section 521. The medium grinding section 521 has the grinding wheel 112, spindle 113, and drive section 114 shown in FIG. 6. The medium grinding section 521 is configured to be movable vertically and horizontally along the support column 522. The grain size of the abrasive grains of the grinding wheel 112 of the medium grinding section 521 is smaller than the grain size of the abrasive grains of the grinding wheel 112 of the rough grinding section 511.

[0191] The finish grinding unit 530 finish-grinds the processing surface Wg of the wafer W to be processed. The finish grinding unit 530 has a finish grinding section 531. The finish grinding section 531 has the grinding wheel 112, spindle 113, and drive section 114 shown in FIG. 6. The finish grinding section 531 is configured to be movable vertically and horizontally along the support column 532. The grain size of the abrasive grains of the grinding wheel 112 of the finish grinding section 531 is smaller than the grain size of the abrasive grains of the grinding wheel 112 of the medium grinding section 521.

[0192] Next, a description will be given of wafer processing performed using the substrate processing system 400 configured as above. In this embodiment, the description will be given in conjunction with the case where the wafer processing shown in FIG.

[0193] First, a cassette Ct containing a plurality of overlapping wafers T is placed on a cassette placement table 410 of the carry-in / out station 401. In this embodiment, the processing target wafer W and the support wafer S are bonded in a bonding device (not shown) outside the substrate processing system 400, as shown in FIG.

[0194] Next, the overlapped wafer T is removed from the cassette Ct by the wafer transfer device 422 and transferred to the transition device 434. Subsequently, the overlapped wafer T is removed from the transition device 434 by the wafer transfer device 432 and transferred to the processing device 450.

[0195] The overlapped wafer T transported to the processing device 450 is transferred to the processing unit 480. In the processing unit 480, a detection unit (not shown) adjusts the horizontal orientation of the processing target wafer W. The processing unit 480 further uses the laser head 103 to form a modified layer M on the processing target wafer W as shown in FIG. 30(b), and then uses the laser head 321 to form a modified surface R4 or R5 on the processing target wafer W as shown in FIG. 30(c).

[0196] Next, the overlapped wafer T is transported by the transport unit 470 from the processing unit 480 to the delivery position A0 and delivered to the chuck 461 at the delivery position A0. Thereafter, the chuck 461 is moved to the first processing position A1. Then, the rough grinding unit 510 roughly grinds the processing surface Wg of the processing target wafer W as shown in FIG. 30(d). As a result, the peripheral portion We of the processing target wafer W is peeled off and removed from the modified layer M and the crack C as shown in FIG. 30(e). At this time, since the modified surface R4 or R5 is formed at the interface between the processing target wafer W and the support wafer S and the bonding strength is reduced, the peripheral portion We can be appropriately removed.

[0197] Next, the chuck 461 is moved to the second processing position A2. Then, the processing surface Wg of the wafer W to be processed is medium-ground by the medium grinding unit 520. If the peripheral edge We cannot be completely removed by the rough grinding unit 510, the peripheral edge We is completely removed by the medium grinding unit 520. That is, the peripheral edge We may be removed in two stages, by the rough grinding unit 510 and the medium grinding unit 520. In such a case, the size of the peripheral edge We to be removed can be reduced in stages. That is, the peripheral edge We removed by each grinding unit 510, 520 becomes smaller.

[0198] Next, the chuck 461 is moved to the third processing position A3. Then, the finish grinding unit 530 finish-grinds the processing surface Wg of the processing target wafer W.

[0199] Next, the chuck 461 is moved to the delivery position A0. Here, the processing surface Wg of the processing target wafer W is roughly cleaned with a cleaning liquid using a cleaning liquid nozzle (not shown). At this time, cleaning is performed to remove contamination from the processing surface Wg to a certain extent.

[0200] Next, the overlapped wafer T is transferred by the transfer unit 470 from the delivery position A0 to the second cleaning unit 500. Then, in the second cleaning unit 500, with the processing target wafer W held on the transfer pad 472, the non-bonding surface Sn of the support wafer S is cleaned and dried.

[0201] Next, the overlapped wafer T is transferred by the transfer unit 470 from the second cleaning unit 500 to the first cleaning unit 490. Then, in the first cleaning unit 490, the processing surface Wg of the processing target wafer W is finish-cleaned with a cleaning liquid using a cleaning liquid nozzle (not shown). At this time, the processing surface Wg is cleaned and dried to a desired cleanliness level.

[0202] Next, the overlapped wafer T is transferred by the wafer transfer device 432 to the wet etching devices 440 and 441 in this order, and the processing surface Wg is wet etched in two stages.

[0203] Thereafter, the overlapped wafer T that has been subjected to all the processes is transferred by the wafer transfer device 432 to the transition device 434, and further transferred by the wafer transfer device 422 to the cassette Ct on the cassette mounting table 10. In this way, a series of wafer processes in the substrate processing system 400 is completed.

[0204] In the third embodiment described above, it is possible to obtain the same effects as in the first and second embodiments.

[0205] The substrate processing system 400 of this embodiment may further include an edge removing device 210. The edge removing device 210 is provided, for example, stacked on the processing unit 480 and the first cleaning unit 490.

[0206] In this case, after the modified layer M and the modified surface R4 or R5 are formed in the processing unit 480, the peripheral portion We is removed in the peripheral edge removal device 210 starting from the modified layer M. Then, rough grinding in the rough grinding unit 510, medium grinding in the medium grinding unit 520, finish grinding in the finish grinding unit 530, cleaning of the non-bonding surface Sn in the second cleaning unit 500, cleaning of the processing surface Wg in the first cleaning unit 490, and wet etching of the processing surface Wg in the wet etching devices 440 and 441 are performed in this order.

[0207] In this embodiment, the laser head 103 for forming the modified layer M and the laser head 321 for forming the modified surface R4 or R5 are each provided in the processing unit 480 that aligns the overlapped wafer T, but the device configuration is not limited to this. The modified layer forming unit, which includes the laser head 103, the moving mechanism 104, and the lifting mechanism 105 and forms the modified layer M, and the interface processing unit, which includes the laser head 321, the moving mechanism 322, and the lifting mechanism 323 and forms the modified surface R4 or R5, may each be provided separately from the processing unit 480. The modified layer forming unit and the interface processing unit can be located at any position within a range in which the transport unit 470 can transport the overlapped wafer T. For example, the modified layer forming unit and the interface processing unit may be stacked on the processing unit 480. Alternatively, they may be located horizontally adjacent to the processing unit 480, for example, on the opposite side of the processing unit 480 across the moving mechanism 473. Either the modified layer forming unit or the interface treatment unit may be disposed inside the processing apparatus 450. Alternatively, both the modified layer forming unit and the interface treatment unit may be disposed outside the processing apparatus 50.

[0208] The substrate processing system 400 of this embodiment may also be provided with a CMP (Chemical Mechanical Polishing) apparatus that polishes the processing surface Wg of the wafer W to be processed, and in such a case, a cleaning apparatus that cleans the processing surface Wg after polishing may also be provided. The CMP apparatus may be provided, for example, in the processing station 402, on the negative Y-axis side of the wafer transfer region 430. The cleaning apparatus may also be provided, for example, stacked on the wet etching apparatuses 440 and 441, on the positive X-axis side of the wafer transfer region 430.

[0209] Furthermore, in the substrate processing system 400 of this embodiment, the bonding of the target wafer W and the support wafer S is performed by a bonding device external to the substrate processing system 400, but such a bonding device may be provided inside the substrate processing system 400. In such a case, cassettes Cw, Cs, and Ct each capable of accommodating a plurality of target wafers W, a plurality of support wafers S, and a plurality of overlapping wafers T, are carried in and out of the carry-in / out station 401 of the substrate processing system 400. These cassettes Cw, Cs, and Ct can be freely placed in a row in the Y-axis direction on the cassette mounting table 410.

[0210] In the above embodiment, the case where the processing target wafer W and the support wafer S are directly bonded to each other has been described, but the processing target wafer W and the support wafer S may also be bonded to each other via an adhesive.

[0211] Although the present invention has been described above by way of example, it is understood that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and that such modifications and alterations are also within the technical scope of the present invention. [Explanation of symbols]

[0212] 1. Substrate Processing System 2 Loading / unloading station 3 Processing Stations 22 Wafer transport device 30 Joining equipment 31 Modified layer forming device 32 Processing equipment 40 Control device 100 Chuck 101 Moving mechanism 102 Rotation mechanism 103 Laser Head 104 Moving mechanism 105 Lifting mechanism 200 Substrate Processing System 210 Edge removal device 300, 310 Interface treatment device 320, 330 Processing equipment 400 Substrate Processing System 401 Loading / unloading station 402 Processing Station 450 Processing equipment 480 processing units 510 Rough Grinding Unit 520 Medium Grinding Unit 530 Finish Grinding Unit C Crack D Device Layer Fw, Fs oxide film M modified layer M' radial modification layer M” Split modified layer R1, R2 modified grooves R3, R4, R5 modified surface S Support wafer T Polymerized Wafer W (W1, W2) Wafer to be processed Wc central part We Periphery

Claims

1. A substrate processing system for processing a laminated substrate in which a first substrate and a second substrate are bonded together, comprising: a modified layer forming device including a holder for holding the laminated substrate, and irradiating the first substrate held by the holder with laser light to form a modified layer inside the first substrate; a processing device including a second holding unit for holding the laminated substrate, the processing device performing a processing process for reducing the thickness of the first substrate held by the second holding unit; a program storage unit for storing a program; a control device having a computer that reads the program from the program storage unit and runs the program, The program a program that runs on the computer of the control device and controls the substrate processing system to cause the substrate processing system to execute a substrate processing method, The substrate processing method includes: irradiating a laser beam from a processing surface side of the first substrate of the laminated substrate by the modified layer forming device to form a modified layer inside the first substrate along a boundary between a peripheral portion and a central portion of the first substrate to be removed; a processing device for performing a processing process to reduce the thickness of the first substrate from the processing surface side, while peeling and removing the peripheral portion from the first substrate starting from the modified layer.

2. 2. The substrate processing system according to claim 1, the substrate processing method includes forming, by the modified layer forming device, another modified layer inside the first substrate radially outward from the boundary for dividing the peripheral edge portion into small pieces when removing the peripheral edge portion; When forming the other modified layer, a radially modified layer extending radially outward from the boundary is formed inside the first substrate.

3. 3. The substrate processing system according to claim 1, In the substrate processing method, when forming the modified layer, the modified layer is formed by blurring the focus of the laser light so that the lower end of the modified layer is positioned below the target surface of the first substrate after the processing and cracks extending from the modified layer reach the non-processed surface opposite the processed surface.

4. 3. The substrate processing system according to claim 1, In the substrate processing method, when forming the modified layer, the modified layer is formed so that the lower end of the modified layer is positioned above the target surface of the first substrate after the processing, and so that cracks extending from the modified layer reach the non-processed surface opposite the processed surface, but do not reach the processed surface.

5. The substrate processing system according to any one of claims 1 to 4, The processing device is a rotation mechanism that rotates the second holding portion; a grinding wheel that grinds the processing surface of the first substrate; a drive unit that rotates the grinding wheel, In the substrate processing method, when performing the processing, the first substrate and the grinding wheel are rotated in a state where the first substrate and a part of the arc of the grinding wheel are in contact with each other, thereby grinding the processed surface; The grinding wheel is rotated relative to the rotating first substrate from the inside to the outside of the first substrate.

6. The substrate processing system according to any one of claims 1 to 5, In the substrate processing method, the processing step includes at least rough grinding the processed surface; and finish-grinding the processed surface, The peripheral edge is removed before the finish grinding.

7. The substrate processing system according to any one of claims 1 to 6, In the substrate processing method, when the processing is performed, the processing surface is ground, and high-pressure water is applied to the peripheral edge portion from the inside to the outside of the first substrate during the grinding.

8. The substrate processing system according to any one of claims 1 to 7, a transport device for transporting the laminated substrate; In the substrate processing method, the transfer device transfers the laminated substrate, in which the modified layer has been formed inside the first substrate, from the holder to the second holder.

9. The substrate processing system according to any one of claims 1 to 7, a transport device for transporting the laminated substrate; In the substrate processing method, the transfer device transfers the laminated substrate, in which the modified layer has been formed inside the first substrate, from the modified layer forming device to the processing device.

10. The substrate processing system according to any one of claims 1 to 9, The modified layer forming device includes: a modifying unit that irradiates the laser light; a rotation mechanism that rotates the holding unit and the reforming unit relative to each other; a lifting mechanism for lifting and lowering the reforming unit, In the substrate processing method, the laser light is irradiated from the modifying unit while rotating the holding unit that holds the second substrate in the laminated substrate, thereby forming the modified layer inside the first substrate; Then, while continuing to rotate the holding part, the irradiation of the laser light from the modified part is stopped, and then the modified part is raised and the laser light is irradiated from the modified part to form the next modified layer inside the first substrate.

11. A program that runs on a computer of a control device that controls a substrate processing system to cause the substrate processing system to execute a substrate processing method for processing a laminated substrate in which a first substrate and a second substrate are bonded together, the substrate processing system, a modified layer forming device including a holder for holding the laminated substrate, and irradiating the first substrate held by the holder with laser light to form a modified layer inside the first substrate; a processing device including a second holding unit for holding the laminated substrate, the processing device performing a processing process for reducing the thickness of the first substrate held by the second holding unit; the control device having a program storage unit for storing the program, The substrate processing method includes: irradiating a laser beam from a processing surface side of the first substrate of the laminated substrate by the modified layer forming device to form a modified layer inside the first substrate along a boundary between a peripheral portion and a central portion of the first substrate to be removed; The program includes: peeling and removing the peripheral portion from the first substrate starting from the modified layer while performing a processing process to reduce the thickness of the first substrate from the processing surface side using the processing device.

12. The program according to claim 11, the substrate processing method includes forming, by the modified layer forming device, another modified layer inside the first substrate radially outward from the boundary for dividing the peripheral edge portion into small pieces when removing the peripheral edge portion; When forming the other modified layer, a radially modified layer extending radially outward from the boundary is formed inside the first substrate.

13. 13. The program according to claim 11 or 12, In the substrate processing method, when forming the modified layer, the modified layer is formed by blurring the focus of the laser light so that the lower end of the modified layer is positioned below the target surface of the first substrate after the processing and cracks extending from the modified layer reach the non-processed surface opposite the processed surface.

14. 13. The program according to claim 11 or 12, In the substrate processing method, when forming the modified layer, the modified layer is formed so that the lower end of the modified layer is positioned above the target surface of the first substrate after the processing, and so that cracks extending from the modified layer reach the non-processed surface opposite the processed surface, but do not reach the processed surface.

15. The program according to any one of claims 11 to 14, The processing device is a rotation mechanism that rotates the second holding portion; a grinding wheel that grinds the processing surface of the first substrate; a drive unit that rotates the grinding wheel, In the substrate processing method, when performing the processing, the first substrate and the grinding wheel are rotated in a state where the first substrate and a part of the arc of the grinding wheel are in contact with each other, thereby grinding the processed surface; The grinding wheel is rotated relative to the rotating first substrate from the inside to the outside of the first substrate.

16. The program according to any one of claims 11 to 15, In the substrate processing method, the processing step includes at least rough grinding the processed surface; and finish-grinding the processed surface, The peripheral edge is removed before the finish grinding.

17. The program according to any one of claims 11 to 16, In the substrate processing method, when the processing is performed, the processing surface is ground, and high-pressure water is applied to the peripheral edge portion from the inside to the outside of the first substrate during the grinding.

18. The program according to any one of claims 11 to 17, the substrate processing system includes a transfer device that transfers the laminated substrate; In the substrate processing method, the transfer device transfers the laminated substrate, in which the modified layer has been formed inside the first substrate, from the holder to the second holder.

19. The program according to any one of claims 11 to 17, the substrate processing system includes a transfer device that transfers the laminated substrate; In the substrate processing method, the transfer device transfers the laminated substrate, in which the modified layer has been formed inside the first substrate, from the modified layer forming device to the processing device.

20. The program according to any one of claims 11 to 19, The modified layer forming device includes: a modifying unit that irradiates the laser light; a rotation mechanism that rotates the holding unit and the reforming unit relative to each other; a lifting mechanism for lifting and lowering the reforming unit, In the substrate processing method, the laser light is irradiated from the modifying unit while rotating the holding unit that holds the second substrate in the laminated substrate, thereby forming the modified layer inside the first substrate; Then, while continuing to rotate the holding part, the irradiation of the laser light from the modified part is stopped, and then the modified part is raised and the laser light is irradiated from the modified part to form the next modified layer inside the first substrate.

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