Substrate processing system, and substrate processing method

Abstract

The present invention relates to a substrate processing system for processing a substrate, characterized in that it comprises: a modified layer forming apparatus that forms a modified layer inside the substrate along the boundary between the peripheral portion and the central portion of the substrate that is to be removed; and a peripheral removal apparatus that removes the peripheral portion with the modified layer as a reference point.

Description

[Technical Field]

[0001] (Cross-reference to related patent applications) In this case, priority is claimed based on Japanese Patent Application No. 2018-47159 filed in Japan on March 14, 2018 and Japanese Patent Application No. 2018-87711 filed in Japan on April 27, 2018, the contents of which are incorporated herein by reference.

[0002] This invention relates to a substrate processing system, a substrate processing method, and a computer recording medium. [Previous Technology]

[0003] In recent years, during the manufacturing process of semiconductor devices, a step is performed to thin the back side of a semiconductor wafer (hereinafter referred to as a wafer) on which multiple electronic circuits and other components are formed on its surface. If the thinned wafer is then directly transported and further processed, warping or cracking may occur. Therefore, in order to reinforce the wafer, it is, for example, attached to a support substrate.

[0004] In addition, the periphery of the wafer is usually chamfered. However, as mentioned above, if the wafer is ground, the periphery will form a sharp shape (the so-called blade edge shape). This may cause the wafer to break at the periphery, thus damaging the wafer. Therefore, we perform an edge trimming step, called edge trimming, before grinding the wafer periphery.

[0005] For example, Patent Document 1 discloses a longitudinal axis type end-face grinding apparatus as a device for performing an edge trimming step. When grinding the periphery of a wafer with this end-face grinding apparatus, firstly, the wafer with a support substrate attached is fixed to a platform, and the platform is rotated about an axis parallel to the vertical axis. Then, after rotating the pivot to rotate the grinding tool (i.e., the grinding wheel), the pivot is moved in the vertical direction, thereby causing the grinding surface of the grinding wheel to come into contact with the wafer, and the periphery of the wafer is ground. [Prior Art Documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-216152 [Summary of the Invention]

[0007] [Problem to be Solved by the Invention] However, in the end face grinding apparatus described in Patent Document 1, the vertical movement of the rotating shaft is sometimes not constant due to various main reasons such as tolerances. In this case, it may be impossible to properly control the vertical movement of the grinding wheel, and the grinding may reach the surface of the support substrate. Therefore, there is still room for improvement in the conventional edge trimming process.

[0008] In view of the above problems, the object of the present invention is to appropriately remove the peripheral portion of one of the substrates in a laminated substrate to which the substrates are bonded. [Means for solving the problem]

[0009] An embodiment of the present invention that solves the above problems is a substrate processing system for processing a substrate, characterized in that it includes: a modified layer forming apparatus that forms a modified layer inside the substrate along the boundary between the peripheral portion and the central portion of the substrate that is to be removed; and a peripheral removal apparatus that removes the peripheral portion with the modified layer as a reference point.

[0010] Another embodiment of the present invention is a substrate processing method for processing a substrate, characterized by comprising: a modified layer forming step, wherein a modified layer is formed inside the first substrate along the boundary between the peripheral portion and the central portion of the first substrate that is to be removed; a peripheral removal step, wherein the peripheral portion is removed with the modified layer as a reference point; and a bonding step, wherein the first substrate is bonded to a second substrate.

[0011] Another embodiment of the present invention is a readable computer recording medium that stores a program that runs on a computer controlling the control unit of the substrate processing system to cause the substrate processing system to perform the substrate processing method. [Effects of the Invention]

[0012] According to an embodiment of the present invention, the peripheral portion of one of the substrates can be appropriately removed from the laminated substrates in which the substrates are joined.

Implementation Method

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Furthermore, in this specification and the drawings, elements having substantially the same functional structure will be given the same reference numerals, and repeated descriptions will be omitted.

[0015] First, a first embodiment of the present invention will be described. FIG1 is a top view schematically showing the general structure of the substrate processing system 1 of the first embodiment. In addition, in order to clarify the positional relationships in the following, the X-axis direction, Y-axis direction and Z-axis direction that are orthogonal to each other are defined, and the positive Z-axis direction is the vertically upward direction.

[0016] In the substrate processing system 1, as shown in FIG2, the wafer to be processed W, which serves as the first substrate, is bonded to the support wafer S, which serves as the second substrate, to form a laminated wafer T, which serves as the laminated substrate. Then, the wafer to be processed W is thinned. Hereinafter, in the wafer to be processed W, the surface to be processed (the surface opposite to the surface bonded to the support wafer S) is referred to as the "processed surface Wg", and the surface opposite to the processed surface Wg is referred to as the "unprocessed surface Wn". In addition, in the support wafer S, the surface bonded to the wafer to be processed W is referred to as the "bonding surface Sj", and the surface opposite to the bonding surface Sj is referred to as the "unbonded surface Sn".

[0017] The wafer W to be processed, such as a silicon wafer or other semiconductor wafer, has a plurality of components formed on its non-processed surface Wn. In addition, the periphery of the wafer W to be processed is chamfered, and the thickness of the periphery cross-section decreases towards the front end.

[0018] Support wafer S is a wafer that supports the wafer W to be processed. In addition, support wafer S functions as a protective material for the components on the non-processed surface Wn of the wafer W to be processed. Furthermore, when a plurality of components are formed on the bonding surface Sj of support wafer S, a component layer (not shown in the figure) is formed on the bonding surface Sj in the same manner as on the wafer W to be processed.

[0019] As shown in FIG1, the substrate processing system 1 has, for example, a structure that connects the loading and unloading station 2 and the processing station 3 into one unit; cassettes Cw, Cs, and Ct that can respectively hold a plurality of processed wafers W, a plurality of support wafers S, and a plurality of stacked wafers T are loaded or unloaded between the loading and unloading station 2 and the outside; the processing station 3 is equipped with various processing devices that perform predetermined processing on the processed wafers W, support wafers S, and stacked wafers T.

[0020] A box-holding platform 10 is provided at the loading / unloading station 2. In the example shown in the drawing, a plurality of boxes (e.g., 4) Cw, Cs, and Ct are arbitrarily arranged in a row along the X-axis direction on the box-holding platform 10. Furthermore, the number of boxes Cw, Cs, and Ct placed on the box-holding platform 10 is not limited to this embodiment and can be arbitrarily determined.

[0021] A wafer transport area 20 is provided at the inbound / outbound station 2, adjacent to the cassette mounting stage 10. A wafer transport device 22 is provided in the wafer transport area 20, which can move freely along a transport path 21 extending along the X-axis. The wafer transport device 22 has, for example, two transport arms 23, 23 that hold and transport stacked wafers T. Each transport arm 23 is configured to move freely in the horizontal direction, in the vertical direction, about a horizontal axis, and about a vertical axis. Furthermore, the configuration of the transport arm 23 is not limited to this embodiment and any configuration may be used.

[0022] At the processing station 3, on the positive Y-axis side of the wafer transport area 20, a bonding device 30 for bonding the wafer to be processed W to the supporting wafer S, a modifier layer forming device 31 for forming a modifier layer inside the wafer to be processed W, and a processing device 32 for grinding the processing surface Wg of the wafer to be processed W are arranged side by side from the negative X-axis direction to the positive X-axis direction. Furthermore, the number or arrangement of these bonding devices 30, modifier layer forming device 31, and processing device 32 is not limited to this embodiment and can be arbitrarily determined. In this embodiment, the processing device 32 functions as a peripheral removal device of the present invention.

[0023] A control device 40 is provided in the above-described substrate processing system 1. The control device 40, for example, is a computer, and has a program storage unit (not shown in the figure). The program storage unit stores a program for controlling the processing of the wafer W to be processed, the supporting wafer S, and the stacked wafer T in the substrate processing system 1. In addition, the program storage unit also stores a program for controlling the operation of the drive systems such as the various processing devices or transport devices mentioned above to realize the wafer processing described later in the substrate processing system 1. In addition, this program may be, for example, recorded on a computer-readable recording medium H such as a hard disk (HD), floppy disk (FD), optical disk (CD), magneto-optical disk (MO), or memory card, or it may be installed from the recording medium H onto the control device 40.

[0024] Next, the bonding device 30, the modified layer forming device 31, and the processing device 32 will be described.

[0025] The bonding apparatus 30 uses van der Waals forces and hydrogen bonds (intermolecular forces) to bond the unprocessed surface Wn of the wafer to be processed to the bonding surface Sj of the supporting wafer S. During this bonding, the unprocessed surface Wn and the bonding surface Sj are preferably modified to become hydrophilic. Specifically, when modifying the unprocessed surface Wn and the bonding surface Sj, for example, in a reduced pressure gas environment, the processing gas (i.e., oxygen or nitrogen) is excited to cause it to plasma and ionize. The oxygen ions or nitrogen ions are then irradiated onto the unprocessed surface Wn and the bonding surface Sj to perform plasma treatment on the unprocessed surface Wn and the bonding surface Sj, thereby activating them. In addition, pure water is supplied to the modified unprocessed surface Wn and the bonding surface Sj to make them hydrophilic. Furthermore, the construction of the bonding apparatus 30 is arbitrary, and conventional bonding apparatuses can be used.

[0026] The modified layer forming apparatus 31 irradiates the interior of the wafer W to be processed with laser light to form a modified layer. As shown in FIG3, the modified layer forming apparatus 31 has a chuck 100 as a holding part, in which the wafer W to be processed is positioned on the upper side and the supporting wafer S is positioned on the lower side. The chuck 100 is configured to be movable in the X-axis and Y-axis directions by means of a moving mechanism 101. The moving mechanism 101 is configured as a general precision XY platform. Furthermore, the chuck 100 is configured to be rotatable about a vertical axis by means of a rotating mechanism 102.

[0027] Above the chuck 100, a laser head 103, serving as a modification section, is provided to irradiate the interior of the wafer W to be processed with laser light. The laser head 103 concentrates high-frequency pulsed laser light emitted from a laser oscillator (not shown) at a predetermined position inside the wafer W to be processed. This laser light has a wavelength that is penetrable relative to the wafer W. As shown in FIG. 4, the portion of the interior of the wafer W to which the laser light L is concentrated is modified to form a modification layer M. The modification layer M extends in the thickness direction and has a length-to-width ratio. The laser head 103 shown in FIG. 3 can also be configured to move in the X-axis and Y-axis directions via a moving mechanism 104. The moving mechanism 104 is a general precision XY platform. Alternatively, the laser head 103 can also be configured to move in the Z-axis direction via a lifting mechanism 105.

[0028] In the modified layer forming apparatus 31, firstly, the stacked wafer T is held in place by the chuck 100. Then, the chuck 100 is moved horizontally by the moving mechanism 101 to center the stacked wafer T. Simultaneously, the position is adjusted by the moving mechanism 104 so that the laser head 103 is directly above a predetermined position of the stacked wafer T (the wafer W to be processed). Then, while the chuck 100 is rotated by the rotating mechanism 102, laser light L is irradiated into the interior of the wafer W from the laser head 103, as shown in FIG. 5, forming a ring-shaped modified layer M on the wafer W. Additionally, to perform the above-mentioned position adjustment, a camera (not shown in the figure) for capturing the position of the stacked wafer T can also be provided in the modified layer forming apparatus 31.

[0029] The location of the modified layer M on the wafer W to be processed will be described in detail below. In the substrate processing system 1, the processing surface Wg of the wafer W to be processed, which is bonded to the support wafer S, is ground. However, in order to avoid forming a cutting edge on the periphery of the wafer W after grinding, the periphery is removed before grinding. The modified layer M is the reference point for removing the periphery, and as shown in FIG5, it forms a ring along the boundary between the periphery We and the central part Wc of the wafer W to be processed, which is the object to be removed. In addition, the periphery We includes a chamfered portion, for example, within a radius of 0.5 mm to 2.0 mm from the end of the wafer W to the center.

[0030] Furthermore, as shown in Figure 4, the lower end of the modified layer M is located above the target surface of the processed wafer W after grinding (the dashed line in Figure 4). That is, the distance H1 between the lower end of the modified layer M and the unprocessed 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 any value, but it is greater than the target thickness H2, for example, 5 μm to 10 μm. In this case, no modified layer M remains on the processed wafer W after grinding.

[0031] In addition, in the modified layer forming apparatus 31 of this embodiment, the chuck 100 is moved in the horizontal direction, but the laser head 103 can also be moved in the horizontal direction, or both the chuck 100 and the laser head 103 can be moved in the horizontal direction. Furthermore, the chuck 100 is rotated, but the laser head 103 can also be rotated.

[0032] The processing apparatus 32 performs grinding processing on the processing surface Wg of the wafer W to be processed. Specifically, the processing apparatus 32 may include, for example, a grinding unit for grinding the processing surface Wg, and a cleaning unit for cleaning the processing surface Wg of the wafer W to be processed or the non-bonded surface Sn supporting the wafer S.

[0033] As shown in FIG6, the grinding unit 110 has a chuck 111 that holds the stacked wafer T with the wafer W to be processed on the upper side and the supporting wafer S on the lower side. The chuck 111 is configured to be rotatable about a vertical axis by means of a rotation mechanism (not shown in the figure).

[0034] An annular grinding stone 112 is provided above the chuck 111. A drive unit 114 is provided on the grinding stone 112 across the rotating shaft 113. The drive unit 114 has a built-in motor (not shown in the figure) for example, which causes the grinding stone 112 to rotate and move in both the vertical and horizontal directions.

[0035] Then, in the grinding unit 110, while the wafer W to be processed held by the chuck 111 is in contact with a portion of the arc of the grinding stone 112, the chuck 111 and the grinding stone 112 are rotated respectively, thereby grinding the processing surface Wg of the wafer W to be processed.

[0036] Next, the wafer processing performed using the substrate processing system 1 configured as described above will be explained.

[0037] First, the cassette Cw containing a plurality of processed wafers W and the cassette Cs containing a plurality of supporting wafers S are placed on the cassette placement stage 10 of the loading and unloading station 2.

[0038] Next, the wafer to be processed W is removed from the cassette Cw using the wafer transport device 22 and transported to the bonding device 30. Then, the support wafer S is also removed from the cassette Cs using the wafer transport device 22 and transported to the bonding device 30. In the bonding device 30, with the wafer to be processed W positioned on the upper side and the support wafer S positioned on the lower side, they are bonded using Van der Waals forces and intermolecular forces to form a laminated wafer T. At this time, if the unprocessed surface Wn of the wafer to be processed and the bonding surface Sj of the support wafer S are activated using, for example, oxygen or nitrogen ions from plasma, Van der Waals forces and intermolecular forces will be appropriately generated.

[0039] Next, the stacked wafer T is transported by the wafer transport device 22 to the modifier layer forming apparatus 31. The stacked wafer T, transported to the modifier layer forming apparatus 31, is transferred and held in the chuck 100. Then, the chuck 100 is moved horizontally by the moving mechanism 101 to center the stacked wafer T, and the position is adjusted so that the laser head 103 is directly above a predetermined position of the stacked wafer T (the wafer to be processed W). This predetermined position is the boundary between the peripheral portion We and the central portion Wc of the wafer to be processed W. Then, while the chuck 100 is rotated by the rotating mechanism 102, laser light L is irradiated into the interior of the wafer to be processed from the laser head 103, as shown in FIG. 7(a), forming an annular modifier layer M inside the wafer to be processed W. The formation position of the modifier layer M is as explained in FIG. 4 and FIG. 5 above.

[0040] Next, the stacked wafer T is transported to the processing apparatus 32 by the wafer transport device 22. The stacked wafer T transported to the processing apparatus 32 is transferred and held in the chuck 111. Then, as shown in FIG7(b), with the wafer W to be processed in contact with a portion of the arc of the grinding stone 112, the grinding stone 112 is lowered, and the chuck 111 and the grinding stone 112 are rotated respectively, thereby grinding the processing surface Wg of the wafer W to be processed.

[0041] During the grinding of the processing surface Wg, crack C propagates from the modified layer M along the thickness direction inside the processed wafer W and reaches both the processing surface Wg and the unprocessed surface Wn. Crack C propagates in a generally straight line because the processed wafer W has a single-crystal silicon structure. Furthermore, crack C forms a ring shape when viewed from above. Additionally, crack C sometimes propagates during the formation of the modified layer M by the modified layer forming apparatus 31. In other words, the formation timing of crack C can occur either during the grinding of the processing surface Wg by the processing apparatus 32 or during the formation of the modified layer M by the modified layer forming apparatus 31.

[0042] Furthermore, if the grinding of the processing surface Wg is continued, the peripheral portion We of the processed wafer W, as shown in FIG7(c), will be peeled off with the modified layer M and the crack C as reference points. At this time, the crack C, as described above, advances in a roughly straight line, so the outer surface of the processed wafer W after removal has fewer irregularities and is flatter. In addition, the lower end of the modified layer M, as described above, is located above the target surface of the processed wafer W after grinding, so the modified layer M will be removed when the processing surface Wg is ground. The modified layer M has an amorphous structure and is relatively weak. Regarding this point, in this embodiment, no modified layer M remains in the processed wafer W after grinding, so strong strength can be ensured.

[0043] In the modified layer forming apparatus 31, the peripheral portion We is removed, and the processing surface Wg of the wafer W being processed is ground to the target thickness.

[0044] Afterwards, all the processed stacked wafers T are transported by the wafer transport device 22 to the cassette Ct of the cassette stage 10. Thus, a series of wafer processing in the substrate processing system 1 is completed.

[0045] Next, a variation of the first embodiment will be described. In the above embodiment, after the wafer to be processed W is bonded to the support wafer S by the bonding device 30, the modifier layer M is formed inside the wafer to be processed W by the modifier layer forming device 31. However, in this variation, the order is reversed.

[0046] That is, in the substrate processing system 1, firstly, the wafer to be processed W is taken out from the cassette Cw by the wafer transport device 22 and transported to the modifier layer forming apparatus 31. In the modifier layer forming apparatus 31, as shown in FIG8(a), a modifier layer M is formed at a predetermined position inside the wafer to be processed W.

[0047] In addition, while the modified layer M is formed in the modified layer forming apparatus 31, the support wafer S in the cassette Cs is taken out by the wafer transport device 22 and transported to the bonding device 30.

[0048] Next, the wafer to be processed W is transported by the wafer transport device 22 to the bonding device 30. In the bonding device 30, as shown in FIG8(b), the wafer to be processed W is bonded to the support wafer S to form a stacked wafer T.

[0049] Next, the stacked wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, as shown in FIG8(c), with a portion of the arc of the grinding stone 112 in contact with the wafer to be processed, the grinding stone 112 is lowered, and the chuck 111 and the grinding stone 112 are rotated respectively, thereby grinding the processing surface Wg of the wafer to be processed. Then, as shown in FIG8(d), the peripheral portion We is removed, and the processing surface Wg of the wafer to be processed is ground to the target thickness.

[0050] After that, all the processed stacked wafers T are transported by the wafer transport device 22 to the cassette Ct of the cassette stage 10. In this way, a series of wafer processing in the substrate processing system 1 is completed.

[0051] Based on the first embodiment and the variations described above, the following advantages can be enjoyed. In the following description, a comparison is made with the conventional method of grinding away the periphery of the wafer being processed using a grinding wheel (grinding tool). In addition, there is also a conventional method of removing the periphery of the wafer being processed using a cutting tool (grinding tool), which has the same problems as the method of using a grinding wheel.

[0052] After the wafer to be processed is bonded to the support wafer, as in the conventional method described in Patent Document 1 above, where the peripheral portion of the wafer to be processed in the stacked wafer is ground away with a grinding wheel, there is a risk that "due to various main reasons such as tolerances, the vertical movement of the grinding wheel cannot be properly controlled, and the grinding reaches the surface of the support wafer." In contrast, in this embodiment, by forming a modifier layer M inside the wafer to be processed W, the peripheral portion We can be removed using the modifier layer M and the crack C as reference points. At this time, the bonding surface Sj of the support wafer S will not be damaged by grinding or the like.

[0053] In conventional methods where the periphery of the wafer to be processed is ground away with a grinding wheel before bonding the wafer to be processed with the support wafer, there is a risk that "microparticles may be generated due to grinding, and these microparticles may adhere to the components of the wafer to be processed." In contrast, in this embodiment, since the periphery We is peeled away using the modified layer M and the crack C formed inside the wafer to be processed as reference points, no microparticles are generated. Therefore, especially in the variant embodiment shown in FIG8, even if the wafer to be processed before bonding is processed, the components on the non-processed surface Wn will not be contaminated.

[0054] In conventional applications using grinding wheels, the horizontal position adjustment of the grinding wheel has its limits, resulting in an error of approximately several μm. Consequently, the width of the peripheral portion removed by the grinding wheel (trimming width) also becomes inaccurate, leading to poor processing precision. In contrast, in this embodiment, since a modifier layer M is formed inside the wafer W being processed using a laser, a high precision of, for example, less than 1 μm can be ensured. Therefore, the precision of the width of the peripheral portion We removed with the modifier layer M as the reference point (trimming width) is also improved.

[0055] In conventional designs using grinding wheels, the grinding wheel is lowered to grind the periphery, thus limiting the rotational speed of the chuck holding the wafer being processed, making it time-consuming to remove the periphery. In contrast, in this embodiment, a modified layer M is formed inside the wafer W being processed using a high-frequency laser, allowing for a faster rotational speed of the chuck 100 and enabling processing in a very short time. Therefore, wafer processing throughput can be increased.

[0056] In the past, grinding wheels were used, which wore down and required regular replacement. Furthermore, grinding water was used during grinding, necessitating wastewater treatment. This resulted in higher operating costs. In contrast, in this embodiment, the laser head 103 body does not deteriorate over time, reducing maintenance frequency. Additionally, since a dry laser process is used, grinding water or wastewater treatment is unnecessary. Therefore, operating costs are significantly lower.

[0057] Furthermore, notches are formed on semiconductor wafers (i.e., the wafers being processed W) to indicate the orientation of the crystallization. However, in the conventional step of removing the peripheral portion We using a cutting tool, it is difficult to directly retain the shape of the notch. In contrast, in this embodiment, for example in the modifier layer forming apparatus 31, by performing relative motion control on the wafers being processed W and the laser light, the modifier layer M can be formed in accordance with the notch shape. Therefore, the peripheral portion We can be easily removed while directly retaining the notch shape.

[0058] Furthermore, in the above embodiments, regarding the method for efficiently removing the peripheral portion We when grinding the processed surface Wg, there are methods such as "rotating the grinding stone 112 from the outside to the inside of the processed wafer W relative to the rotating processed wafer W, or rotating the grinding stone 112 from the inside to the outside of the processed wafer W relative to the rotating processed wafer W". The rotation direction of the grinding stone 112 can be changed according to the type of processed wafer W or the processing step.

[0059] In addition, when grinding the processing surface Wg, a high-pressure water jet can be sprayed from the inside of the wafer W to the periphery We to effectively remove the periphery We (spraying it off).

[0060] In addition, in a variation of the first embodiment described above, the steps of forming the modified layer M in the modified layer forming apparatus 31, bonding the processed wafer W and the support wafer S in the bonding apparatus 30, and removing the peripheral portion We in the processing apparatus 32 are performed sequentially. However, the order of the wafer bonding step and the peripheral portion We removal step can be reversed. That is, the steps of forming the modified layer M in the modified layer forming apparatus 31, removing the peripheral portion We in the processing apparatus 32, and bonding the processed wafer W and the support wafer S in the bonding apparatus 30 can also be performed sequentially.

[0061] Next, a second embodiment of the present invention will be described. FIG9 is a top view schematically showing the general structure of the substrate processing system 200 of the second embodiment. In the structure of the substrate processing system 1 of the first embodiment, the substrate processing system 200 further includes a peripheral removal device 210 for removing the peripheral portion We of the wafer W to be processed at the processing station 3. The peripheral removal device 210 is, for example, disposed between the modified layer forming apparatus 31 and the processing apparatus 32.

[0062] The peripheral removal apparatus 210 removes the peripheral portion We by applying force to a portion further outward of the modified layer M after the modified layer forming apparatus 31 forms the modified layer M on the wafer to be processed. That is, in the first embodiment, the peripheral portion We is removed while the processing apparatus 32 is grinding the processing surface Wg of the wafer to be processed, but in the second embodiment, the peripheral removal apparatus 210 performs the removal step of the peripheral portion We.

[0063] As shown in FIG10, the peripheral removal device 210 has a chuck 211 that holds the stacked wafer T with the wafer W to be processed on the upper side and the supporting wafer S on the lower side. The chuck 211 is configured to be rotatable about a vertical axis by means of a rotation mechanism (not shown in the figure).

[0064] Above the chuck 211, there is an annular grinding wheel 212. A drive unit 214 is provided on the grinding wheel 212 across the rotating shaft 213. The drive unit 214 has a built-in motor (not shown in the figure) to rotate the grinding wheel 212 and move it in both the vertical and horizontal directions. In this embodiment, a grinding wheel 212 is used, but it is not limited to this; for example, a cutting tool can also be used.

[0065] Then, in the peripheral removal apparatus 210, with the peripheral portion We of the wafer W being processed, held by the chuck 211, in contact with a portion of the arc of the grinding wheel 212, the chuck 211 and the grinding wheel 212 are rotated respectively, thereby applying an impact to the peripheral portion We. Through this impact, the peripheral portion We is removed. At this time, the accuracy of the removed surface of the wafer W can be ensured by forming the modified layer M.

[0066] Next, the wafer processing performed using the substrate processing system 200 configured as described above will be described. In this embodiment, detailed descriptions of processes identical to those in the first embodiment are omitted.

[0067] First, the wafer to be processed, W, is taken out of the cassette Cw using the wafer transport device 22 and transported to the modifier layer forming apparatus 31. In the modifier layer forming apparatus 31, as shown in FIG11(a), a modifier layer M is formed at a predetermined position inside the wafer to be processed, W.

[0068] In addition, while the modified layer M is formed in the modified layer forming apparatus 31, the supporting wafer S in the cassette Cs is taken out by the wafer transport device 22 and transported to the bonding device 30.

[0069] Next, the wafer to be processed W is transported by the wafer transport device 22 to the bonding device 30. In the bonding device 30, as shown in FIG11(b), the wafer to be processed W is bonded to the support wafer S to form a stacked wafer T.

[0070] Next, the stacked wafer T is transported by the wafer transport device 22 to the peripheral removal device 210. In the peripheral removal device 210, as shown in FIG11(c), a portion of the arc of the grinding wheel 212 is brought into contact with the outermost part of the wafer W to be processed, beyond the modified layer M. In this state, the grinding wheel 212 is lowered, and the chuck 211 and the grinding wheel 212 are rotated simultaneously to apply an impact to the peripheral portion We of the wafer W to be processed. By this impact, as shown in FIG11(d), the peripheral portion We is peeled off with reference points to the modified layer M and the crack C.

[0071] Next, the stacked wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, as shown in FIG11(e), the processing surface Wg of the wafer W to be processed is ground to the target thickness.

[0072] Afterwards, all the processed stacked wafers T are transported by the wafer transport device 22 to the cassette Ct of the cassette stage 10. Thus, a series of wafer processing in the substrate processing system 1 is completed.

[0073] In the second embodiment described above, the same effects as in the first embodiment described above can be enjoyed.

[0074] In addition, in the second embodiment, as shown in FIG11, the steps of forming the modified layer M, bonding the processed wafer W and the supporting wafer S, removing the peripheral portion We, and grinding the processing surface Wg of the processed wafer W are performed sequentially. However, the order of the steps of forming the modified layer M and bonding the processed wafer W and the supporting wafer S can be reversed. That is, the steps of bonding the processed wafer W and the supporting wafer S, forming the modified layer M, removing the peripheral portion We, and grinding the processing surface Wg of the processed wafer W can also be performed sequentially.

[0075] The above embodiments are described in relation to bonding one processed wafer W to a wafer S, but can also be used for bonding between semiconductor wafers with components, or for stacking a plurality of processed wafers W with components. In the following description, a plurality of processed wafers W with components are stacked using the substrate processing system 1 of the first embodiment.

[0076] As shown in FIG12(a), the periphery We of the processed wafer W in the first embodiment is removed, and the processing surface Wg is ground to the target thickness. In the following description, the first processed wafer W is referred to as the first processed wafer W1.

[0077] The stacked wafer T is transported to the bonding device 30 by the wafer transport device 22. Additionally, the wafer W to be processed, which is to be stacked next as the third substrate, is also transported to the bonding device 30 by the wafer transport device 22. In the following description, this second processed wafer W is referred to as the second processed wafer W2. Then, in the bonding device 30, as shown in FIG12(a), the processed surface Wg of the first processed wafer W1 is bonded to the unprocessed surface Wn of the second processed wafer W2 to form the stacked wafer T.

[0078] Next, the stacked wafer T is transported by the wafer transport device 22 to the modification layer forming device 31. In the modification layer forming device 31, as shown in FIG12(b), a modification layer M is formed at a predetermined position inside the second processed wafer W2.

[0079] Next, the stacked wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, as shown in FIG12(c), with a portion of the arc of the grinding stone 112 in contact with the second wafer to be processed, the grinding stone 112 is lowered, and the chuck 111 and the grinding stone 112 are rotated respectively, thereby grinding the processing surface Wg of the second wafer to be processed. Then, as shown in FIG12(d), the peripheral portion We is removed, and the processing surface Wg of the second wafer to be processed is ground to the target thickness.

[0080] After that, all the processed stacked wafers T are transported by the wafer transport device 22 to the cassette Ct of the cassette stage 10. In this way, a series of wafer processing in the substrate processing system 1 is completed.

[0081] Here, when the periphery We of the second processed wafer W2 is removed from the stacked wafer T shown in FIG12(a) using a grinding wheel as in the conventional method, it is difficult to grind the periphery We because the area below the non-processed surface Wn of the second processed wafer W2 is hollow. In contrast, in this embodiment, by forming a modifier layer M inside the second processed wafer W2, the periphery We can be easily removed using the modifier layer M and the crack C as reference points.

[0082] Furthermore, in conventional embodiments using grinding wheels or cutting tools, the horizontal position adjustment of the grinding wheel or cutting tool has its limits, resulting in an error of approximately several μm. Consequently, the width (trimming width) of the peripheral portion removed by the grinding wheel or cutting tool also introduces errors, especially when stacking processed wafers, this error gradually accumulates. Therefore, for example, sometimes the processed wafer on the upper layer may exceed the processed wafer on the lower layer. In contrast, in this embodiment, since a modified layer M is formed inside the second processed wafer W2 using a laser, higher precision can be ensured, thereby allowing for proper stacking of the processed wafers W.

[0083] Furthermore, when multiple processed wafers W are stacked as in this embodiment, the peripheral portion We removed from the upper second processed wafer W2 can be located inside the peripheral portion We removed from the lower first processed wafer W1. That is, as shown in FIG13(a), the modified layer M inside the second processed wafer W2 can be formed at a location radially inward than the end of the first processed wafer W1. In this case, as shown in FIG13(b), the diameter of the finally stacked second processed wafer W2 is smaller than the diameter of the first processed wafer W1. In this way, it is possible to reliably prevent the second processed wafer W2 from exceeding the diameter of the first processed wafer W1.

[0084] In the modified layer forming apparatus 31 of the above embodiment, the modified layer M shown in FIG4 is formed at point I such that its lower end is above the target surface of the wafer W after grinding. However, the method of forming the modified layer M is not limited to this.

[0085] As shown in Figures 14(a) to (d), the modified layer M can also be formed at multiple locations in the thickness direction of the wafer W being processed. Furthermore, Figure 14 shows the element layer or oxide film formed at the interface between the wafer W being processed and the supporting wafer S on the laminated wafer T. That is, an element layer D having multiple elements is formed on the non-processed surface Wn of the wafer W being processed, and an oxide film Fw (e.g., a SiO2 film) is further formed on the element layer D. Additionally, an oxide film Fs is also formed on the bonding surface Sj of the supporting wafer S. Furthermore, when multiple elements are also formed on the bonding surface Sj of the supporting wafer S, similar to the wafer W being processed, an element layer (not shown in the figure) is also formed on the bonding surface Sj.

[0086] In the example shown in FIG14(a), the modifier layers M1 to M4 are formed in multiple segments (e.g., 4 segments) in the thickness direction of the wafer W to be processed. The lower end of the bottom modifier layer M4 is located above the target surface of the wafer W to be processed after grinding [the dashed line in FIG14(a)]. In addition, the cracks C formed by the modifier layers M1 to M4 reach the processed surface Wg and the unprocessed surface Wn of the wafer W to be processed.

[0087] In the example shown in FIG14(b), the modified layers M1 to M2 are formed in multiple segments (e.g., 2 segments) in the thickness direction of the wafer W to be processed. The lower end of the lower modified layer M2 is located above the target surface of the wafer W after grinding [the dotted line in FIG14(b)]. In addition, the crack C formed by the modified layers M1 to M2 reaches the non-processed surface Wn of the wafer W to be processed, but does not reach the processed surface Wg. At this time, for example in the processing apparatus 32, when the grinding stone 112 is lowered to grind the processed surface Wg, the processed surface Wg, including the peripheral portion We of the wafer W to be processed, is ground until the grinding surface of the grinding stone 112 reaches the crack C. Then, when the grinding surface of the grinding stone 112 reaches the crack C, the peripheral portion We is peeled off from the crack C downwards. By controlling the height of the upper end of the crack C extending from the modified layer M1 to M2 at a predetermined position, the size (height) of the removed peripheral fragments We can be controlled.

[0088] In the example shown in FIG14(c), modifier layers M1 to M4 are formed in multiple segments (e.g., 4 segments) in the thickness direction of the wafer W to be processed. The lower end of the lowest modifier layer M4 is located below the target surface of the wafer W after grinding [the dotted line in FIG14(c)]. In addition, the cracks C formed by these modifier layers M1 to M4 reach the processing surface Wg and the non-processing surface Wn of the wafer W to be processed. At this time, since the modifier layer M4 is formed at the boundary between the peripheral portion We and the central portion Wc in the wafer W to be ground, the peripheral portion We can be peeled off more reliably. In addition, when the modifier layer M4 is formed below the target surface in this way, the concentrated light of the laser light is diffused, so that the cracks C extending from the modifier layer M4 are less likely to be generated. In this way, the generation of cracks C can be suppressed and reach the support wafer S bonded to the wafer W to be processed. Although the location of crack C may change in the entire surrounding direction, it can still be removed with good precision because the lower end of the modified layer M4 can be controlled in this way.

[0089] In the example shown in FIG14(d), the modifier layers M1 to M4 are formed in multiple segments (e.g., 4 segments) in the thickness direction of the wafer W being processed. The lower end of the bottom modifier layer M4 is located inside the element layer D. In addition, the crack C formed by the modifier layers M1 to M4 reaches the processing surface Wg of the wafer W being processed. Similarly, since the modifier layer M4 is formed at the boundary between the peripheral portion We and the central portion Wc in the wafer W being processed after grinding, the peripheral portion We can be peeled off more reliably.

[0090] The method of forming a plurality of modifier layers M in the thickness direction of the wafer W to be processed, as shown in Figure 14, is an arbitrary method. However, three processing methods as shown in Figure 15 can be listed as examples. Figure 15 is a diagram showing the portion of the wafer W to be processed in which the modifier layer M is formed (the boundary between the peripheral portion We and the central portion Wc) is unfolded on a plane. That is, the horizontal direction of Figure 15 represents the direction around the boundary between the peripheral portion We and the central portion Wc, and the vertical direction represents the thickness direction of the wafer W to be processed. In addition, the dashed lines in Figure 15 represent modifier layers M1 to M4, and show the state in which a plurality of modifier layers M1 to M4 are formed in the thickness direction of the wafer W to be processed.

[0091] In the processing method shown in FIG. 15(a), in the modified layer forming apparatus 31, while the chuck 100 is rotated by the rotation mechanism 102, laser light is irradiated into the interior of the wafer W to be processed from the laser head 103 fixed in the vertical direction 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 laser head 103 is raised to a predetermined position (i.e., the position where the modified layer M3 is formed) by the lifting mechanism 105. Then, while the chuck 100 is rotated, laser light is irradiated from the laser head 103 to form an annular modified layer M3. Modified layers M2 and M1 are also formed in the same manner, thereby forming modified layers M1 to M4 on the wafer W to be processed.

[0092] Alternatively, during the formation of modified layers M1 to M4, the irradiation of the laser light from the laser head 103 can be controlled to be ON and OFF while the chuck 100 continues to rotate. For example, while the chuck 100 is rotated, laser light is irradiated into the interior of the wafer W to be processed from the laser head 103 to form modified layer M4. Then, while the chuck 100 continues to rotate, the irradiation of the laser light from the laser head 103 is temporarily stopped. Next, the laser head 103 is raised, and laser light is irradiated into the interior of the wafer W to be processed again from the laser head 103 to form modified layer M3. Furthermore, at this time, the start and end positions of the laser light irradiation during the formation of modified layer M4 can be recorded to match the start and end positions of the laser light irradiation during the subsequent formation of modified layer M3. Then, since the rotation of the chuck 100 is not stopped as described above, the standby time of laser irradiation during the acceleration and deceleration of the chuck 100's rotation can be shortened, thereby shortening the overall processing time. Furthermore, by maintaining a constant rotation speed of the chuck 100, laser processing can be performed uniformly, and the horizontal spacing of the modified layers M can be made equal.

[0093] In the processing method shown in FIG15(b), while the chuck 100 is rotated using the rotation mechanism 102, laser light is irradiated onto the interior of the wafer W to be processed from the laser head 103 fixed in the vertical direction to form an annular modified layer M4. Before the formation step of the modified layer M4 is completed, while the chuck 100 continues to rotate and the laser light from the laser head 103 continues to irradiate, the laser head 103 is raised to a predetermined position (i.e., the position where the modified layer M3 is formed) using the lifting mechanism 105. Then, while the vertical position of the laser head 103 is fixed, laser light is irradiated from the laser head 103 while the chuck 100 is rotated to form an annular modified layer M3. Modified layers M2 and M1 are also formed in the same manner, forming modified layers M1 to M4 on the wafer W to be processed. At this time, since modified layers M1 to M4 can be continuously formed, the processing time can be shortened compared to the processing method shown in Figure 15(a).

[0094] In the processing method shown in FIG15(c), the chuck 100 is rotated by the rotating mechanism 102, and the laser head 103 is raised by the lifting mechanism 105. Laser light is irradiated from the laser head 103 onto the interior of the wafer W to be processed, thereby continuously forming annular modified layers M1 to M4. That is, in this processing method, the modified layers M1 to M4 are continuously formed in a spiral manner. Similarly, since the modified layers M1 to M4 can be continuously formed, the processing time can be shortened compared to the processing method shown in FIG15(a). Moreover, in side view, the modified layers M1 to M4 are not formed in a steep slope manner, and compared to the processing method shown in FIG15(b), they can be formed more evenly in the vertical direction (the thickness direction of the wafer W to be processed).

[0095] In the above embodiment, an annular modified layer M is formed inside the wafer W being processed in the modified layer forming apparatus 31. However, as shown in FIG16, a plurality of radial modified layers M' extending radially outward from the annular modified layer M can also be formed. In this case, for example, when the peripheral portion We is removed by the processing apparatus 32, the peripheral portion We is peeled off with the annular modified layer M as the reference point, and is also divided into a plurality of pieces by the radial modified layers M'. As a result, the removed peripheral portion We becomes smaller, and it can be removed more easily.

[0096] Furthermore, regarding the method for fragmenting the peripheral portion We (edge ​​piece) removed during grinding of the machined surface Wg, as shown in FIG16, a plurality of annular segmented modified layers M” can be formed at arbitrary intervals in a direction concentric with the modified layer M”. In this case, the removed peripheral portion We can be segmented into smaller pieces. In addition, by controlling the radial interval of the segmented modified layers M”, the size of the fragments of the removed peripheral portion We can be controlled.

[0097] Furthermore, when forming a plurality of annular segmented modified layers M” in this way, as shown in FIG17, the segmented modified layers M” can also be formed into a spiral shape when viewed from above. In this case, in the modified layer forming apparatus 31, by moving the chuck 100 or the laser head 103 in the horizontal direction, while rotating the chuck 100, laser light is irradiated onto the wafer W to be processed from the laser head 103, and the spiral segmented modified layers M” can be formed continuously. As a result, the processing time required can be shortened.

[0098] Additionally, as shown in FIG18, the segmented modified layer M” can also be formed in a spiral and serpentine shape when viewed from above. In this case, in the modified layer forming apparatus 31, the chuck 100 or laser head 103 is moved in the horizontal direction, while the chuck 100 is rotated and laser light is irradiated onto the wafer W to be processed from the laser head 103. At this time, by controlling the phase, period, and amplitude of the movement of the chuck 100 or laser head 103, the serpentine wave-shaped segmented modified layer M” can be formed. In addition, the segmented modified layer M” is formed in two or more turns. Then, by controlling the offset of the serpentine phase or the number of turns of the segmented modified layer M”, the size of the fragments of the removed peripheral portion We can be controlled. In addition, in this embodiment, the radial modified layer M’ shown in FIG16 and FIG17 is not required.

[0099] Alternatively, as shown in FIG19(a), the split-modification layer M” can be formed by extending the crack C from the split-modification layer M” to a predetermined position inside the wafer W being processed. That is, the crack C reaches the non-processed surface Wn of the wafer W being processed, but does not reach the processed surface Wg. At this time, for example, when the grinding stone 112 is lowered in the processing apparatus 32 to grind the processed surface Wg, as shown in FIG19(b), the processed surface Wg, including the peripheral portion We of the wafer W being processed, is ground until the grinding surface of the grinding stone 112 reaches the crack C. Then, when the grinding surface of the grinding stone 112 reaches the crack C, the peripheral portion We below the crack C is peeled off. By controlling the upper height of the crack C at a predetermined position in this way, the size (height) of the fragments of the removed peripheral portion We can be controlled. In addition, in the example of Figure 19, the segmented modified layer M” is formed into two segments. However, it is also possible to form two segments of segmented modified layer M at the same time by adjusting the light concentration point of the laser head 103 to two points, so that the chuck 100 can be rotated at the same time.

[0100] In the above embodiments, the following method can also be used to efficiently remove the peripheral portion We. That is, for example, before the bonding device 30 bonds the wafer W to be processed to the support wafer S, the peripheral portion We can be efficiently removed by reducing the bonding force at the interface between the wafer W to be processed and the support wafer S, corresponding to the portion of the peripheral portion We that is removed. A specific example of the method for reducing this bonding force is as follows.

[0101] The first method for reducing bonding strength is, for example, to roughen the unprocessed surface Wn of the wafer W to be processed, which corresponds to the portion of the peripheral portion We that has been removed, by irradiating it with laser light or the like. Specifically, the interface processing apparatus 300 shown in FIG20 is used. In addition, the interface processing apparatus 300 is provided at any position in the processing station 3 of the substrate processing system 1, for example.

[0102] The interface processing apparatus 300 includes a chuck 301 that holds the wafer W to be processed with its non-processed surface Wn facing upwards. The chuck 301 is configured to move in the X-axis and Y-axis directions via a moving mechanism 302. The moving mechanism 302 is a typical precision XY platform. Furthermore, the chuck 301 is configured to rotate about a vertical axis via a rotating mechanism 303.

[0103] Above the chuck 301, a laser head 304 is provided to irradiate laser light K onto the unprocessed surface Wn of the peripheral portion We of the wafer W being processed. The laser light K irradiated by the laser head 304 can be any laser light, such as an excimer laser or a fiber laser. As described above, a device layer D and an oxide film Fw are formed on the unprocessed surface Wn, and the laser light can be any wavelength (e.g., 266 nm) that will be absorbed by the oxide film Fw. In addition, the laser head 304 can also be configured to be movable in the X-axis direction, Y-axis direction, and Z-axis direction by means of a moving mechanism (not shown in the figure).

[0104] The laser light irradiation port of the laser head 304 is configured to be movable in the horizontal direction by means of a moving mechanism (not shown in the figure). The moving mechanism may, for example, move the irradiation port of the laser head 304 mechanically, or it may be moved by an acoustic element. The laser light is absorbed by the oxide film Fw, so there is no need to strictly control its light concentration point. Therefore, as in this embodiment, the irradiation port of the laser head 304 can be moved by means of a moving mechanism to modify the unprocessed surface Wn (oxide film Fw) of the peripheral portion We, thereby roughening its surface.

[0105] Above the chuck 301, a gas supply unit 305 is provided for supplying gas to the wafer W to be processed. The gas supplied by the gas supply unit 305 is, for example, an inert gas such as clean air or nitrogen. The gas supply unit 305 has a nozzle 306 for supplying gas and a rectifier plate 307 for rectifying the gas supplied by the nozzle 306. The nozzle 306 is connected to a gas supply source (not shown in the figure) that stores and supplies gas. In addition, the gas supply port of the nozzle 306 is formed above the center of the wafer W to be processed. The rectifier plate 307 is configured to be roughly parallel to the wafer W to be processed held by the chuck 301, so as to control the flow of gas from the nozzle 306 on the non-processed surface Wn of the wafer W to be processed.

[0106] Around the chuck 301, a cup-shaped portion 308 is provided for collecting and discharging gas from the gas supply unit 305. An exhaust pipe 309 for discharging gas is connected to the bottom surface of the cup-shaped portion 308. In addition, the cup-shaped portion 308 may cover the entire periphery of the wafer W being processed, or it may only partially cover the periphery of the laser head 304.

[0107] In the interface processing apparatus 300, firstly, after holding the wafer W to be processed in the chuck 301, the chuck 301 is moved horizontally by the moving mechanism 302 to center the wafer W to be processed. Then, while rotating the chuck 301 by the rotating mechanism 303, laser light K is irradiated from the laser head 304 onto the unprocessed surface Wn of the peripheral portion We of the wafer W to be processed, thereby roughening the surface of the unprocessed surface Wn.

[0108] Additionally, when roughening the surface of the unprocessed surface Wn, gas is supplied to the unprocessed surface Wn of the wafer W being processed from the gas supply section 305. The supplied gas flows over the entire surface of the unprocessed surface Wn and is discharged from the exhaust pipe 309. When the unprocessed surface Wn of the peripheral portion We is modified with laser light as in this embodiment, debris (waste) is sometimes generated. If this debris adheres to the unprocessed surface Wn of the central portion Wc, the device may be damaged. Therefore, by supplying gas from the gas supply section 305 for cleaning, the adhesion of debris to the unprocessed surface Wn can be suppressed. In addition, the unprocessed surface Wn can also be cleaned in another cleaning device (not shown in the figure) after the interface treatment of the interface treatment apparatus 300. At this time, for example, compared to a configuration that does not supply gas between the rectifier plate 307 and the wafer W being processed, as in the interface processing device 300, this embodiment will be cleaned in the interface processing device 300, so the cleaning degree of the other cleaning devices mentioned above can be reduced to a lighter degree of cleaning.

[0109] Alternatively, as shown in FIG21, at the location where the surface of the unprocessed surface Wn of the processed wafer W is roughened, for example, the boundary between the unprocessed surface Wn of the processed wafer W corresponding to the portion of the removed peripheral portion We and the unprocessed surface Wn of the processed wafer W corresponding to the portion of the unremoved central portion Wc can be modified to form a modification groove R1, which serves as a bonding force reduction portion. Furthermore, a plurality of annular modification grooves R2 can be formed on the outside of the modification groove R1. Alternatively, as shown in FIG22, the portion corresponding to the peripheral portion We can be modified in a planar manner to form a surface-roughened modification surface R3. In this case, the modification surface R3 can be formed by a plurality of modification grooves R2, or the irradiation range of the laser light can be adjusted to form the modification surface R3.

[0110] Next, the wafer processing performed by the substrate processing system 1 equipped with the interface processing apparatus 300 described above will be described. In this embodiment, detailed descriptions of processes identical to those in the first embodiment are omitted.

[0111] First, the wafer to be processed, W, is taken out of the cassette Cw using the wafer transport device 22 and transported to the interface processing device 300. In the interface processing device 300, as shown in FIG23(a), the non-processed surface Wn (oxide film Fw) at the periphery We of the wafer to be processed is modified to form any one of the surface roughening modification grooves R1, R2, and modification surface R3.

[0112] In addition, while the surface roughening of the non-processed surface Wn of the interface processing device 300 is performed, the support wafer S in the cassette Cs is taken out by the wafer transport device 22 and transported to the bonding device 30.

[0113] Next, the wafer to be processed, W, is transported to the bonding device 30 by the wafer transport device 22. At this time, the wafer to be processed, W, is flipped over by the wafer transport device 22 or a flipping device (not shown in the figure). In the bonding device 30, as shown in FIG23(b), the wafer to be processed, W, is bonded to the support wafer, S, to form a stacked wafer, T.

[0114] Next, the stacked wafer T is transported by the wafer transport device 22 to the modification layer forming apparatus 31. In the modification layer forming apparatus 31, as shown in FIG23(c), a modification layer M is formed at a predetermined position inside the wafer W to be processed. That is, the modification layer M is formed in a manner corresponding to the modification trenches R1 to R3.

[0115] Next, the stacked wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, as shown in FIG23(d), the processing surface Wg of the wafer to be processed is ground to the target thickness. If the grinding of the processing surface Wg continues, as shown in FIG23(e), the peripheral portion We of the wafer to be processed is peeled off with reference points to the modified layer M and the crack C. At this time, since the bonding force of the interface (non-processed surface Wn) between the wafer to be processed and the supporting wafer S is reduced by surface roughening, the peripheral portion We can be appropriately removed.

[0116] After that, all the processed stacked wafers T are transported by the wafer transport device 22 to the cassette Ct of the cassette stage 10. Thus, a series of wafer processing in the substrate processing system 1 is completed.

[0117] In this embodiment, as shown in FIG23(a), any one of the modification trenches R1, R2, and modification surface R3 is formed on the wafer W to be processed. Then, as shown in FIG23(b), the wafer W to be processed is bonded to the supporting wafer S. Then, as shown in FIG23(c), a modification layer M is formed on the wafer W to be processed. However, this is not limited to this order. For example, the steps of forming modification trenches R1, R2, and modification surface R3, forming modification layer M, and bonding wafers W and S can also be performed in the following order. Alternatively, the steps of forming modification layer M, forming modification trenches R1, R2, and modification surface R3, and bonding wafers W and S can also be performed in the following order. Furthermore, the steps of forming modification layer M, bonding wafers W and S, and forming modification trenches R1, R2, and modification surface R3 can also be performed in the following order.

[0118] In addition, in this embodiment, the interface processing device 300 is provided separately from the modified layer forming device 31, although the interface processing device 300 and the modified layer forming device 31 may also be the same device. In this case, for example, a laser head 304 is provided in the modified layer forming device 31.

[0119] Alternatively, a protective film may be formed on the unprocessed surface Wn before the laser processing in the interface processing apparatus 300. In this case, a coating apparatus (not shown in the figure) for forming the protective film and a cleaning apparatus (not shown in the figure) for cleaning the protective film are provided in the processing station 3 of the substrate processing system 1. The coating apparatus, for example, uses a spin coating method to coat the entire surface of the unprocessed surface Wn with a protective material to form a protective film. In addition, the cleaning apparatus, for example, uses a spin cleaning method to supply cleaning liquid to the entire surface of the unprocessed surface Wn to clean the protective film and remove dirt.

[0120] Next, in the substrate processing system 1, a protective film is first formed on the entire surface of the unprocessed surface Wn in a coating apparatus. Then, in the interface processing apparatus 300, as shown in FIG23(a), the unprocessed surface Wn of the peripheral portion We is modified. At this time, since a protective film is formed in the central portion Wc of the wafer to be processed, the device can be prevented from being damaged even if debris is generated by laser light. Then, in the cleaning apparatus, the protective film on the unprocessed surface Wn is cleaned to remove dirt, and then, as shown in FIG23(b), the wafer to be processed W is bonded to the support wafer S.

[0121] The second bonding strength reduction method is, for example, to apply a release agent to the unprocessed surface Wn of the wafer W to be processed, corresponding to the portion of the removed peripheral portion We, to form a release film. Specifically, for example, the interface processing apparatus 310 shown in FIG24 is used. In addition, the interface processing apparatus 310 is provided at any position in the processing station 3 of the substrate processing system 1, for example.

[0122] The interface processing apparatus 310 has a chuck 311 that holds the wafer W to be processed with its non-processed surface Wn facing upward. The chuck 311 is configured to rotate about a vertical axis by means of a rotation mechanism 312.

[0123] Above the chuck 311, a nozzle 313 is provided for applying release agent A to the non-machined surface Wn of the peripheral portion We of the wafer being processed. The nozzle 313 is connected to a release agent supply source (not shown in the figure) that stores and supplies release agent A. Furthermore, the nozzle 313 may be configured to move in the X-axis, Y-axis, and Z-axis directions via a moving mechanism (not shown in the figure). The release agent A may be any material that reduces the bonding force at the interface between the wafer being processed W and the supporting wafer S.

[0124] The wafer processing method implemented using the substrate processing system 1 equipped with the above-described interface processing apparatus 310 is, in the method shown in FIG23, replacing the laser processing of the interface processing apparatus 300 with a release agent coating process of the interface processing apparatus 310. In the interface processing apparatus 310, while rotating the chuck 311, a release agent A is applied from the nozzle 313 to the unprocessed surface Wn of the peripheral portion We, thereby forming a release film on the unprocessed surface Wn. Then, because the bonding force between the processed wafer W and the supporting wafer S is reduced at the peripheral portion We due to the release film, the peripheral portion We can be appropriately removed in FIG23(e).

[0125] Furthermore, when the chuck 311 of the interface processing apparatus 310 rotates at a high speed, the applied release agent A will be thrown to the outside of the wafer W being processed due to centrifugal force. On the other hand, when the chuck 311 rotates at a medium speed, since the release agent A may flow around to the processing surface Wg of the wafer W being processed, a rinsing solution for the release agent A can also be supplied from the processing surface Wg side. In addition, when the chuck 311 rotates at a low speed, the release agent A can also be drawn out from the outside of the wafer W being processed.

[0126] The third method for reducing adhesion is, for example, etching the unprocessed surface Wn of the wafer W to be processed, corresponding to the portion of the peripheral portion We to be removed, with a processing solution to thin it. For example, when it is a TEOS film, etching is performed with fluorescent acid. The interface treatment apparatus for performing this etching can be constructed arbitrarily, and conventional etching apparatus can be used.

[0127] In this embodiment, instead of the laser processing of the interface processing apparatus 300 shown in FIG23(a), an etching process is performed on the peripheral portion We. The etched peripheral portion We is removed, creating a height difference between it and the central portion Wc, or the surface of the etched peripheral portion We is roughened. Thus, when the wafer to be processed W is bonded to the support wafer S by the bonding device 30 as shown in FIG23(b), the wafer W to be processed at the peripheral portion We is not bonded to the support wafer S. Therefore, the peripheral portion We can be appropriately removed in FIG23(e).

[0128] The fourth method for reducing bonding force is, for example, when the bonding apparatus 30 described above is a plasma-based bonding apparatus, a method of irradiating the unprocessed surface Wn of the processed wafer W, corresponding to the portion of the removed peripheral portion We, with plasma during bonding. In the bonding apparatus 30 described above, plasma-generated oxygen or nitrogen ions irradiate the unprocessed surface Wn, causing the unprocessed surface Wn to be activated by plasma treatment. Therefore, in this bonding apparatus 30, a shielding plate can also be provided above the unprocessed surface Wn to prevent oxygen or nitrogen ions from irradiating the unprocessed surface Wn of the peripheral portion We.

[0129] At this time, in the bonding apparatus 30, the unprocessed surface Wn of the central portion Wc of the wafer being processed is activated by oxygen or nitrogen ions, but the unprocessed surface Wn of the peripheral portion We is not activated. Therefore, when the wafer being processed W is bonded to the support wafer S by the bonding apparatus 30 as shown in FIG23(b), the wafer being processed W and the support wafer S are not bonded at the peripheral portion We. Therefore, the peripheral portion We can be appropriately removed in FIG23(e).

[0130] In addition, in the above embodiments, the above four processes are performed on the unprocessed surface Wn of the wafer W to be processed before bonding to reduce the bonding force. However, the same process can also be performed on the bonding surface Sj supporting the wafer S.

[0131] In the above embodiments, regarding the method for efficiently removing the peripheral portion We, after bonding the wafer W to be processed to the support wafer S using the bonding device 30, the bonding force at the interface between the wafer W to be processed and the support wafer S corresponding to the portion of the peripheral portion We to be removed can be reduced, thereby efficiently removing the peripheral portion We. A specific example of the method for reducing this bonding force is as follows.

[0132] For example, laser light is allowed to penetrate into the unprocessed surface Wn of the wafer W being processed, causing erosion at each interface. Specifically, for example, the processing apparatus 320 shown in FIG25 is used. In addition, for example, the processing apparatus 320 is provided in the processing station 3 of the substrate processing system 1 instead of the modified layer forming apparatus 31.

[0133] The processing apparatus 320, in the structure of the modified layer forming apparatus 31, further includes a laser head 321, a moving mechanism 322, and a lifting mechanism 323. The laser head 321 irradiates the non-processed surface Wn with laser light, modifying it. The laser head 321 concentrates high-frequency pulsed laser light emitted by a laser oscillator (not shown) at a predetermined position inside the wafer W to be processed; this laser light has a wavelength that can penetrate the wafer W. This modulates the portion of the wafer W inside that is concentratedly irradiated by the laser light. The moving mechanism 322 moves the laser head 321 in the X-axis and Y-axis directions. The moving mechanism 322 is constructed from a general precision XY platform. The lifting mechanism 323 moves the laser head 321 in the Z-axis direction. As described above, the processing apparatus 320 serves as both a modified layer forming apparatus and an interface processing apparatus.

[0134] When the processing apparatus 320 processes the interface between the wafer W to be processed and the supporting wafer S, it modifies the interior of the wafer W to be processed or the interior of the device layer D. That is, the interface in this embodiment includes the interior of the wafer W to be processed and the interior of the device layer D.

[0135] As shown in Figure 26, when the interior of the wafer W to be processed is modified, a modified surface R4 is formed near the non-processed surface Wn on the periphery We (outside the modified layer M). This processing method, as shown in Figure 27, involves irradiating the interior of the wafer W to be processed with laser light L from the laser head 321. The laser light L penetrates the interior of the wafer W and concentrates its irradiation, modifying the concentrated irradiated portion. Then, the chuck 100 is rotated using the rotation mechanism 102, while the laser head 321 is moved radially outward using the moving mechanism 322, and laser light L is irradiated into the interior of the wafer W from the laser head 321. Thus, the modified surface R4 is formed. Alternatively, when forming the modified surface R4, the chuck 100 can be moved radially using the moving mechanism 101, or both the laser head 321 and the chuck 100 can be moved.

[0136] Furthermore, when the modified surface R4 is formed inside the processed wafer W in this way, after the peripheral portion We is removed, a portion of the processed wafer W will remain on the supporting wafer S. Therefore, after the peripheral portion We is removed, the remaining portion of the processed wafer W can also be etched away.

[0137] As shown in Figure 28, when the interior of the element layer D is modified, a modified surface R5 is formed inside the element layer D, which is attached to the peripheral portion We (outside the modified layer M). Regarding this processing method, there are, for example, three methods as shown in Figure 29.

[0138] The first processing method is as shown in FIG29(a), in which the laser light L of the laser head 321 is concentrated inside the wafer W to be processed and above the device layer D. At this time, the energy of the laser light L is reduced to a level that will not alter the quality of the wafer W even if the laser light L is concentrated and irradiated. Thus, the laser light L is first concentrated inside the wafer W to be processed, and then defocused and diffused, penetrating the wafer W to irradiate the device layer D. The laser light L is absorbed by the device layer D, and the device layer D is etched. Then, the chuck 100 is rotated by the rotation mechanism 102, while the laser head 321 is moved radially outward by the moving mechanism 322, and the laser light L is irradiated from the laser head 321. Thus, a modified surface R5 is formed on the device layer D. In addition, when forming the modified surface R5, the moving mechanism 101 can be used to move the chuck 100 radially, or both the laser head 321 and the chuck 100 can be moved.

[0139] The second processing method is as shown in FIG29(b), which concentrates the laser light L of the laser head 321 inside the element layer D. At this time, the laser light L penetrates the wafer being processed W and irradiates the element layer D, causing the element layer D to be etched. Then, the chuck 100 is rotated by the rotation mechanism 102, while the laser head 321 is moved radially outward by the moving mechanism 322, and the laser light L is irradiated from the laser head 321. In this way, a modified surface R5 is formed on the element layer D. Alternatively, when forming the modified surface R5, the chuck 100 can be moved radially by the moving mechanism 101, or both the laser head 321 and the chuck 100 can be moved.

[0140] The third processing method is as shown in FIG29(c), which positions the laser light L of the laser head 321 below the element layer D. In this method, the laser light L penetrates the wafer W being processed and irradiates the element layer D, causing etching of the element layer D. Furthermore, since the laser light L is absorbed by the element layer D, it does not concentrate below the element layer D. Then, the chuck 100 is rotated using the rotation mechanism 102, while the laser head 321 is moved radially outward using the moving mechanism 322, and laser light L is irradiated from the laser head 321. Thus, a modified surface R5 is formed on the element layer D. Alternatively, when forming the modified surface R5, the chuck 100 can be moved radially using the moving mechanism 101, or both the laser head 321 and the chuck 100 can be moved.

[0141] Furthermore, when the modified surface R5 is formed on the element layer D, the erosion effect in the element layer D at the periphery We may affect the element layer D at the central part Wc inside it. Therefore, it is advisable to form the modified surface R5 after the modified layer M4 is formed on the element layer D as shown in FIG14(d). At this time, the modified layer M4 functions to prevent the erosion effect, thus reliably preventing the erosion effect from affecting the central part Wc.

[0142] Next, the wafer processing performed using the substrate processing system 1 equipped with the processing apparatus 320 described above will be described. In this embodiment, detailed descriptions of processes identical to those in the first embodiment are omitted.

[0143] First, the wafer to be processed W is removed from the cassette Cw using the wafer transport device 22 and transported to the bonding device 30. Next, the support wafer S is also removed from the cassette Cs using the wafer transport device 22 and transported to the bonding device 30. In the bonding device 30, as shown in FIG30(a), the wafer to be processed W is bonded to the support wafer S to form a stacked wafer T.

[0144] Next, the stacked wafer T is transported to the processing apparatus 320 by the wafer transport device 22. In the processing apparatus 320, the laser head 103 is moved above the peripheral portion We. Then, while the chuck 100 is rotated, laser light is irradiated into the interior of the wafer W to be processed from the laser head 103, as shown in FIG30(b), forming a modified layer M at a predetermined position inside the wafer W to be processed.

[0145] Next, in the processing apparatus 320, the laser head 103 is retracted and the laser head 321 is moved above the peripheral portion We. Then, the chuck 100 is rotated while the laser head 321 is moved radially outward, and laser light is irradiated from the laser head 321. Thereby, as shown in FIG30(c), modified surfaces R4 or R5 are formed in the interior of the wafer W being processed or in the device layer D, respectively.

[0146] In addition, the formation steps of the modified layer M shown in FIG30(b) and the formation steps of the modified surface R4 or R5 shown in FIG30(c) can be reversed.

[0147] Next, the stacked wafer T is transported by the wafer transport device 22 to the processing device 32. In the processing device 32, as shown in FIG30(d), the processing surface Wg of the wafer to be processed is ground to the target thickness. If the grinding of the processing surface Wg continues, as shown in FIG30(e), the peripheral portion We of the wafer to be processed is peeled off with reference points to the modified layer M and the crack C. At this time, since the bonding force is reduced due to the formation of the modified surface R4 or R5 at the interface between the wafer to be processed and the supporting wafer S, the peripheral portion We can be appropriately removed.

[0148] After that, all the processed stacked wafers T are transported by the wafer transport device 22 to the cassette Ct of the cassette stage 10. In this way, a series of wafer processing in the substrate processing system 1 is completed.

[0149] In this embodiment, the same effects as in the first and second embodiments described above are also achieved. Furthermore, in the processing apparatus 320, the same chuck 100 is used to perform the formation steps of the modified layer M and the modified surface R4 or R5. Therefore, during the processing of the laser head 103 and the laser head 321, the center of the wafer W being processed will not shift. As a result, the position of the modified layer M can be aligned with the inner periphery of the modified surface R4 or R5, thereby allowing the peripheral portion We to be appropriately removed.

[0150] In addition, in the processing apparatus 320, laser head 103 and laser head 321 do not need to be separately provided, and can also be common laser heads. In addition, laser head 103 and laser head 321 in the processing apparatus 320 can also be provided in other devices, or can be provided in the modified layer forming apparatus 31 and the interface processing apparatus respectively.

[0151] In addition, the embodiment shown in FIG12, in which a second processed wafer W2 is stacked on top of a composite wafer T, can also be applied. In this case, if the position of the peripheral portion We to be removed from the second processed wafer W2 is consistent with the position of the composite wafer T, the step of forming the modified surface R4 or R5 can be omitted.

[0152] Furthermore, the embodiment shown in FIG13, in which the peripheral portion We removed from the upper second processed wafer W2 is located inside the peripheral portion We removed from the lower first processed wafer W1, is also applicable. However, in this case, in the second processed wafer W2, a modified surface R4 or R5 is preferably formed in the peripheral portion We removed from the first processed wafer W1.

[0153] In the above embodiments, it is advisable that the position of the modified trench R1 formed on the wafer W before bonding, the inner periphery of the modified surface R3, or the inner periphery of the modified surfaces R4 and R5 formed on the wafer W after bonding, are consistent with the position of the crack C extending from the modified layer M.

[0154] To illustrate the reasoning, as an example, Figure 31 shows a case where the processed wafer W is bonded relative to the stacked wafer T with a center offset, and the position of the modifier layer M is offset from the inner periphery of the modifier surface R4. In this case, as shown in Figure 31, there are portions where the modifier layer M is located radially inward than the inner periphery of the modifier surface R4, and portions where the modifier layer M is located radially outward than the inner periphery of the modifier surface R4.

[0155] When the modifier layer M, as shown in FIG32(a), is located radially inward than the inner periphery of the modifier surface R4, during the grinding of the processing surface Wg of the wafer W to remove the peripheral portion We, as shown in FIG32(b), the width D1 of the removed peripheral portion may sometimes be smaller than the target width D2 of the peripheral portion We to be removed. In addition, since the removed peripheral portion is not separated from the crack C by the modifier layer M, the outer surface of the wafer W after the peripheral portion is removed may be rougher.

[0156] In addition, when the modified layer M is located further radially inward than the inner periphery of the modified surface R4, but the distance between the modified layer M and the inner periphery of the modified surface R4 is very small, the peripheral portion We can be removed because the bonding force between the processed wafer W and the supporting wafer S is very small.

[0157] When the modified layer M, as shown in FIG33(a), is located radially outward from the inner periphery of the modified surface R4, as shown in FIG33(b), after the processing surface Wg of the wafer being processed is ground to remove the peripheral portion We, the modified surface R4 will remain between the wafer being processed and the device layer D. In the portion where the modified surface R4 exists, the wafer being processed and the device layer D may sometimes peel off, and breakage may occur.

[0158] Regarding methods for eliminating the deviation between the position of the modified layer M and the inner periphery of the modified surface R4, the following two methods can be considered. The first method involves detecting the center offset of the processed wafer W in the laminated wafer T, and adjusting the position of the modified layer M or the inner periphery of the modified surface R4 based on the detection result. The second method involves detecting the position of the modified layer M or the inner periphery of the modified surface R4, and adjusting the position of the modified surface R4 or the modified layer M formed by subsequent processing based on the detection result.

[0159] When implementing the above two deviation elimination methods, for example, the processing device 330 shown in FIG34 is used. For example, the processing device 330 is provided in the processing station 3 of the substrate processing system 1 instead of the processing device 320. The processing device 330, in the configuration of the processing device 320, further includes an eccentricity detection unit 331 for implementing the first deviation elimination method and a position detection unit 332 for implementing the second deviation elimination method.

[0160] The first deviation elimination method will now be described. An eccentricity detection unit 331 is disposed above the center of the chuck 100. Furthermore, the eccentricity detection unit 331 is configured to move in the X-axis, Y-axis, and Z-axis directions via a moving mechanism (not shown). The eccentricity detection unit 331 may include, for example, a CCD camera. Then, the eccentricity detection unit 331 photographs the stacked wafer T held by the chuck 100, specifically, for example, at least three points on the outer periphery. Then, the deviation of the center of the processed wafer W relative to the rotation center of the chuck 100, i.e., the center offset of the processed wafer W in the stacked wafer T, is detected. Furthermore, the configuration of the eccentricity detection unit 331 is not limited to this embodiment; for example, it may also include an IR camera. In this case, the eccentricity detection unit 331, for example, photographs alignment marks formed on the processed wafer W, and detects the center offset of the processed wafer W in the stacked wafer T.

[0161] The first deviation elimination method is implemented using the detection result of the eccentricity detection unit 331. Here, it will be described based on the wafer processing shown in FIG30 performed in the substrate processing system 1.

[0162] First, in the bonding apparatus 30, as shown in FIG30(a), the wafer to be processed W is bonded to the support wafer S to form a stacked wafer T. Next, the stacked wafer T is transported to the processing apparatus 330. In the processing apparatus 330, after the stacked wafer T is held by the chuck 100, the stacked wafer T is photographed using the eccentricity detection unit 331 to detect the center offset of the wafer to be processed W in the stacked wafer T. The detection result of the eccentricity detection unit 331 is output to the control device 40.

[0163] In the control device 40, based on the detection result of the eccentricity detection unit 331, that is, based on the center offset of the wafer W to be processed, 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 is adjusted. By adjusting the central axis of the chuck 100 or the irradiation axis of the laser head 103, a modified layer M can be appropriately formed on the wafer W to be processed, as shown in FIG30(b). In addition, by adjusting the central axis of the chuck 100 or the irradiation axis of the laser head 321, a modified surface R4 can be appropriately formed on the wafer W to be processed, as shown in FIG30(c).

[0164] As described above, based on the detection result of the center offset of the processed wafer W by the eccentricity detection unit 331, the central axis of the chuck 100, the irradiation axis of the laser head 103 or the irradiation axis of the laser head 321 can be adjusted so that the position of the modified layer M is consistent with the inner periphery of the modified surface R4.

[0165] Alternatively, the eccentricity detection unit 331 may also be an eccentricity detection device (not shown in the figure) located outside the processing apparatus 320. In this case, when the stacked wafer T is transported from the eccentricity detection device to the processing apparatus 320 using the wafer transport device 22, the stacked wafer T is transported in a manner that aligns the center of the processed wafer W with the center of the chuck 100, based on the detection result of the center offset of the processed wafer W by the eccentricity detection unit 331. As such, a modification layer M can be appropriately formed on the processed wafer W as shown in FIG30(b), or a modification surface R4 can be appropriately formed inside the processed wafer W or in the component layer as shown in FIG30(c). In this way, the position of the modification layer M can be aligned with the inner periphery of the modification surface R4.

[0166] In addition, the eccentricity detection unit 331 can also detect the center offset of the second processed wafer W2 that is further stacked and bonded to the stacked wafer T. At this time, the position of the modified layer M can be aligned with the inner periphery of the modified surface R4 based on the detection result of the center offset of the second processed wafer W2 relative to the stacked wafer T.

[0167] The second deviation elimination method will now be described. A position detection unit 332 is disposed above the outer periphery of the chuck 100. Furthermore, the position detection unit 332 is configured to be movable in the X-axis, Y-axis, and Z-axis directions via a moving mechanism (not shown). For example, an infrared (IR) camera can be used in the position detection unit 332. Then, the position detection unit 332 detects the position of the modified layer M formed on the wafer T being processed, or the inner periphery of the modified surface R4, on the laminated wafer T held by the chuck 100.

[0168] The second deviation elimination method is implemented using the detection result of the position detection unit 332. Here, it will be explained based on the wafer processing shown in FIG30 performed in the substrate processing system 1.

[0169] First, in the bonding apparatus 30, as shown in FIG30(a), the wafer to be processed W is bonded to the support wafer S to form a stacked wafer T. Next, the stacked wafer T is transported to the processing apparatus 330. In the processing apparatus 330, a modified layer M is formed on the wafer to be processed W using a laser head 103, as shown in FIG30(b).

[0170] After the modified layer M is formed on the wafer W to be processed, the position detection unit 332 uses infrared light to photograph the modified layer M inside the wafer W to detect the position of the modified layer M. The detection result of the position detection unit 332 is output to the control device 40.

[0171] In the control device 40, based on the detection result of the position detection unit 332, that is, based on the position of the modified layer M, the central axis of the chuck 100 or the irradiation axis of the laser head 321 is adjusted. In this way, as shown in FIG30(c), the modified surface R4 can be appropriately formed on the wafer W to be processed. As a result, the position of the modified layer M can be made to coincide with the inner periphery of the modified surface R4.

[0172] Furthermore, the formation steps of the modified layer M shown in FIG. 30(b) and the formation steps of the modified surface R4 shown in FIG. 30(c) can also be reversed in sequence. In this case, after the modified surface R4 is formed on the wafer W to be processed, the position detection unit 332 uses infrared light to photograph the modified surface R4 and detects the inner periphery position of the modified surface R4. The detection result of the position detection unit 332 is output to the control device 40.

[0173] In the control device 40, based on the detection result of the position detection unit 332, that is, based on the inner periphery position of the modified surface R4, the central axis of the chuck 100 or the irradiation axis of the laser head 103 is adjusted. In this way, the modified layer M can be appropriately formed on the wafer W to be processed. As a result, the position of the modified layer M can be made to coincide with the inner periphery position of the modified surface R4.

[0174] Furthermore, in the above embodiments, the position detection unit 332 detects the position of the modified layer M formed on the processed wafer W after bonding or the inner periphery of the modified surface R4. However, it can also detect the position of the modified layer M formed on the processed wafer W before bonding or the inner periphery of the modified surface R4. In this case, the modified surface R4 or the modified layer M can be appropriately formed after the position detection unit 332 detects the modified layer M, so that the position of the modified layer M is consistent with the inner periphery of the modified surface R4.

[0175] In summary, regardless of whether the step of forming the modified layer M or the step of forming the modified surface R4 is performed first, after the position of the modified layer M or the inner periphery of the modified surface R4 is detected by the position detection unit 332, the modified surface R4 or the modified layer M can be formed appropriately, thereby making the position of the modified layer M consistent with the inner periphery of the modified surface R4.

[0176] Next, a substrate processing system according to a third embodiment of the present invention will be described. FIG35 is a top view schematically showing the general structure of the substrate processing system 400 of the third embodiment.

[0177] The substrate processing system 400, for example, has a structure that connects the loading and unloading station 401 and the processing station 402 into one unit; a cassette Ct that can hold a plurality of stacked wafers T is loaded or unloaded between the loading and unloading station 401 and the outside; the processing station 402 is equipped with various processing devices for performing predetermined processing on the stacked wafers T.

[0178] A box-holding platform 410 is provided at the loading / unloading station 401. In the example shown in the drawing, a plurality of boxes (e.g., 4) are arbitrarily arranged in a row along the Y-axis direction on the box-holding platform 410. Furthermore, the number of boxes Ct placed on the box-holding platform 410 is not limited to this embodiment and can be arbitrarily determined.

[0179] A wafer transport area 420 is provided at the inbound / outbound station 401, adjacent to the cassette mounting stage 410. A wafer transport device 422 is provided in the wafer transport area 420, which can move freely along a transport path 421 extending along the Y-axis. The wafer transport device 422 has, for example, two transport arms 423, 423 that hold and transport stacked wafers T. Each transport arm 423 is configured to move freely in the horizontal direction, in the vertical direction, about a horizontal axis, and about a vertical axis. Furthermore, the configuration of the transport arm 423 is not limited to this embodiment and any configuration may be used.

[0180] A wafer transport area 430 is provided in the processing station 402. A wafer transport device 432 is provided in the wafer transport area 430, which can move freely along a transport path 431 extending along the X-axis direction. The wafer transport device 432 is configured to transport the stacked wafer T to the transfer device 434, wet etching devices 440, 441, and processing device 450 (described later). Furthermore, the wafer transport device 432 has, for example, two transport arms 433, 433 that hold and transport the stacked wafer T. Each transport arm 433 is configured to move freely in the horizontal direction, in the vertical direction, about a horizontal axis, and about a vertical axis. Furthermore, the configuration of the transport arm 433 is not limited to this embodiment and any configuration may be used.

[0181] A transfer device 434 for transferring stacked wafers T is provided between wafer transport area 420 and wafer transport area 430.

[0182] On the positive Y-axis side of the wafer transport area 430, wet etching apparatuses 440 and 441 are arranged side by side in the X-axis direction, starting from the transport station 401 side. In the wet etching apparatuses 440 and 441, the processing surface Wg of the wafer to be processed is wet-etched, for example, with a processing solution such as hydrofluoric acid.

[0183] A processing apparatus 450 is arranged on the positive X-axis side of the wafer transport area 430. In the processing apparatus 450, the wafer W to be processed is subjected to processing treatments such as grinding or cleaning. The processing apparatus 450 includes: a rotary table 460, a transport 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 fine grinding unit 530.

[0184] The rotary table 460 is configured to rotate freely using a rotating mechanism (not shown in the figure). Four chucks 461 are provided on the rotary table 460 to hold and hold the stacked wafers T. The chucks 461 are arranged at equal intervals (i.e., every 90 degrees) on the same circumference of the rotary table 460 (which rotates). The four chucks 461 can be moved to the transfer position A0 and the processing positions A1 to A3 by rotating the rotary table 460. Furthermore, each of the four chucks 461 is configured to rotate about a vertical axis using a rotating mechanism (not shown in the figure).

[0185] In this embodiment, the transfer position A0 is located on the negative X-axis and negative Y-axis side of the rotary table 460. On the negative X-axis side of the transfer position A0, the second cleaning unit 500, the processing unit 480, and the first cleaning unit 490 are arranged side-by-side. The processing unit 480 and the first cleaning unit 490 are stacked in this order, starting from top. The first processing position A1 is located on the positive X-axis and negative Y-axis side of the rotary table 460, where a rough grinding unit 510 is arranged. The second processing position A2 is located on the positive X-axis and positive Y-axis side of the rotary table 460, where a medium grinding unit 520 is arranged. The third processing position A3 is located on the negative X-axis and positive Y-axis side of the rotary table 460, where a fine grinding unit 530 is arranged.

[0186] The transport unit 470 is a multi-joint robotic arm with a plurality of (e.g., 3) arms 471. Each of the 3 arms 471 has a freely rotating structure. A transport pad 472 for adsorbing and holding the stacked wafer T is installed on the front arm 471. In addition, a moving mechanism 473 for moving the arm 471 in the vertical direction is installed on the base arm 471. Then, the transport unit 470 with these structures can transport the stacked wafer T to the transfer position A0, the processing unit 480, the first cleaning unit 490, and the second cleaning unit 500.

[0187] In the processing unit 480, the orientation of the horizontal direction of the stacked wafer T before the grinding process is adjusted. For example, while rotating the stacked wafer T held by the chuck 100, the position of the notch portion of the wafer W to be processed is detected by the detection unit (not shown in the figure), thereby adjusting the position of the notch portion and adjusting the orientation of the horizontal direction of the stacked wafer T.

[0188] Furthermore, the processing unit 480 has the structure of the processing apparatus 320, that is, it has 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. Then, in the processing unit 480, a modification layer M is formed on the wafer W to be processed using the laser head 103, and a modification surface R4 or R5 is formed on the wafer W to be processed using the laser head 321. In addition, when the modification layer M is pre-formed on the wafer W to be processed, only the modification surface R4 or R5 is formed in the processing unit 480. Or conversely, when the modification surface R4 or R5 is pre-formed on the wafer W to be processed, only the modification layer M is formed in the processing unit 480.

[0189] In the first cleaning unit 490, the machining surface Wg of the processed wafer W after grinding is cleaned, more specifically, by rotational cleaning. For example, while rotating the stacked wafer T held by the rotary chuck (not shown in the figure), cleaning fluid is supplied to the machining surface Wg from the cleaning fluid nozzle (not shown in the figure). As a result, the supplied cleaning fluid diffuses on the machining surface Wg, and the machining surface Wg is cleaned.

[0190] In the second cleaning unit 500, the non-bonded surface Sn of the supporting wafer S, which is held by the transport pad 472 after grinding, is cleaned, and the transport pad 472 is cleaned at the same time.

[0191] In the rough grinding unit 510, the processing surface Wg of the wafer W to be processed is rough ground. The rough grinding unit 510 has a rough grinding section 511. The rough grinding section 511 has a grinding stone 112, a rotating shaft 113, and a drive section 114 as shown in FIG. 6. In addition, the rough grinding section 511 is configured to be movable along the support column 512 in both the vertical and horizontal directions.

[0192] In the intermediate grinding unit 520, the processing surface Wg of the wafer W to be processed is intermediately ground. The intermediate grinding unit 520 has an intermediate grinding section 521. The intermediate grinding section 521 has a grinding stone 112, a rotating shaft 113, and a drive section 114 as shown in FIG. 6. In addition, the intermediate grinding section 521 is configured to be movable along the support column 522 in both the vertical and horizontal directions. Furthermore, the abrasive grain size of the grinding stone 112 of the intermediate grinding section 521 is smaller than the abrasive grain size of the grinding stone 112 of the coarse grinding section 511.

[0193] In the fine grinding unit 530, the processing surface Wg of the wafer W to be processed is finely ground. The fine grinding unit 530 has a fine grinding section 531. The fine grinding section 531 has a grinding stone 112, a rotating shaft 113, and a drive section 114 as shown in FIG. 6. In addition, the fine grinding section 531 is configured to be movable along the support column 532 in both the vertical and horizontal directions. Furthermore, the abrasive grain size of the grinding stone 112 of the fine grinding section 531 is smaller than the abrasive grain size of the grinding stone 112 of the medium grinding section 521.

[0194] Next, the wafer processing performed using the substrate processing system 400 configured as described above will be explained. In this embodiment, the wafer processing shown in FIG30 will be explained.

[0195] First, a cassette Ct containing a plurality of stacked wafers T is placed on a cassette mounting stage 410 of a transfer station 401. In addition, in this embodiment, the wafer to be processed W is bonded to a support wafer S in a bonding device (not shown in the figure) outside the substrate processing system 400, as shown in FIG30(a).

[0196] Next, the wafer transfer device 422 is used to remove the stacked wafer T from the cassette Ct and transfer it to the transfer device 434. Next, the wafer transfer device 432 is used to remove the stacked wafer T from the transfer device 434 and transfer it to the processing device 450.

[0197] The stacked wafer T, which has been transferred to the processing apparatus 450, is then passed to the processing unit 480. In the processing unit 480, the orientation of the wafer W to be processed is adjusted using a detection unit (not shown in the figure). Furthermore, in the processing unit 480, a modification layer M is formed on the wafer W to be processed using a laser head 103, as shown in FIG30(b), and then a modification surface R4 or R5 is formed on the wafer W to be processed using a laser head 321, as shown in FIG30(c).

[0198] Next, the stacked wafer T is transported from the processing unit 480 to the transfer position A0 by the transport unit 470 and then transferred to the chuck 461 at the transfer position A0. After that, the chuck 461 is moved to the first processing position A1. Then, the processing surface Wg of the wafer W to be processed is rough ground by the rough grinding unit 510, as shown in FIG30(d). As shown in FIG30(e), the peripheral portion We of the wafer W to be processed is peeled off with reference points of the modified layer M and the crack C. At this time, since the bonding force is reduced due to the formation of the modified surface R4 or R5 at the interface between the wafer W to be processed and the supporting wafer S, the peripheral portion We can be appropriately removed.

[0199] 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 moderately ground using the medium grinding unit 520. In addition, when the peripheral portion We cannot be completely removed in the rough grinding unit 510, the peripheral portion We will be completely removed in the medium grinding unit 520. That is, the peripheral portion We can also be removed in two stages using the rough grinding unit 510 and the medium grinding unit 520. At this time, the size of the removed peripheral portion We can be reduced in stages. That is, the peripheral portion We removed by each grinding unit 510, 520 will become smaller.

[0200] Next, the chuck 461 is moved to the third machining position A3. Then, the machining surface Wg of the wafer W to be processed is precision ground using the precision grinding unit 530.

[0201] Next, the chuck 461 is moved to the transfer position A0. Here, the processing surface Wg of the wafer W to be processed is roughly cleaned with cleaning fluid using a cleaning fluid nozzle (not shown in the figure). At this time, cleaning is performed to reduce the dirt on the processing surface Wg to a certain degree.

[0202] Next, the stacked wafer T is transported from the transfer position A0 to the second cleaning unit 500 by the transport unit 470. Then, in the second cleaning unit 500, while the wafer W being processed is held by the transport pad 472, the non-bonded surface Sn of the supporting wafer S is cleaned and dried.

[0203] Next, the stacked wafer T is transferred from the second cleaning unit 500 to the first cleaning unit 490 by the transfer unit 470. Then, in the first cleaning unit 490, the processing surface Wg of the wafer W to be processed is cleaned with cleaning fluid using a cleaning fluid nozzle (not shown in the figure). At this time, the processing surface Wg is cleaned to the desired cleanliness and then dried.

[0204] Next, the stacked wafer T is sequentially transported by the wafer transport device 432 to the wet etching devices 440 and 441, and the processing surface Wg is wet etched in two stages.

[0205] After that, the stacked wafer T, which has undergone all the processing, is transported by the wafer transport device 432 to the transfer device 434, and then by the wafer transport device 422 to the cassette Ct of the cassette stage 10. In this way, a series of wafer processing in the substrate processing system 400 is completed.

[0206] In the third embodiment described above, the same effects as in the first and second embodiments described above can also be enjoyed.

[0207] In addition, the substrate processing system 400 of this embodiment may also have a peripheral removal device 210 as shown in FIG35. The peripheral removal device 210 may be stacked in the processing unit 480 and the first cleaning unit 490, for example.

[0208] At this time, a modified layer M and a modified surface R4 or R5 are formed in the processing unit 480. Then, the peripheral portion We is removed in the peripheral removal device 210 with the modified layer M as the reference point. After that, the rough grinding step of the rough grinding unit 510, the medium grinding step of the medium grinding unit 520, the fine grinding step of the fine grinding unit 530, the cleaning step of the non-joining surface Sn of the second cleaning unit 500, the cleaning step of the processed surface Wg of the first cleaning unit 490, and the wet etching step of the wet etching device 440, 441 on the processed surface Wg are performed in sequence.

[0209] In addition, in this embodiment, the laser head 103 used to form the modified layer M and the laser head 321 used to form the modified surface R4 or R5 are each disposed in the processing unit 480 for aligning the stacked wafer T, but the device structure is not limited to this. The modified layer forming unit, which has a laser head 103, a moving mechanism 104 and a lifting mechanism 105 and forms the modified layer M, and the interface processing unit, which has a laser head 321, a moving mechanism 322 and a lifting mechanism 323 and forms the modified surface R4 or R5, can also be disposed separately from the processing unit 480. The modified layer forming unit and the interface processing unit can be disposed at any position as long as they are within the range that the transport unit 470 can transport the stacked wafer T. For example, the modified layer forming unit and the interface processing unit can also be stacked in the processing unit 480. Alternatively, it can be positioned horizontally adjacent to the processing unit 480, for example, it can be positioned opposite the processing unit 480 where the clamping and moving mechanism 473 is located. Furthermore, either the modified layer forming unit or the interface processing unit can be disposed inside the processing apparatus 450. Alternatively, both the modified layer forming unit and the interface processing unit can be disposed outside the processing apparatus 50.

[0210] Alternatively, a CMP (Chemical Mechanical Polishing) device for polishing the processing surface Wg of the wafer W to be processed can be provided in the substrate processing system 400 of this embodiment. At this time, a cleaning device for cleaning the polished processing surface Wg can also be provided. The CMP device can, for example, be provided in the processing station 402 on the negative Y-axis side of the wafer transport area 430. In addition, the cleaning device can, for example, be stacked on the positive X-axis side of the wafer transport area 430 and provided on the wet etching devices 440 and 441.

[0211] Furthermore, in the substrate processing system 400 of this embodiment, the bonding system between the processed wafer W and the supporting wafer S is implemented using bonding devices provided outside the substrate processing system 400, although such bonding devices may also be provided inside the substrate processing system 400. At this time, cassettes Cw, Cs, and Ct, which can respectively hold a plurality of processed wafers W, a plurality of supporting wafers S, and a plurality of stacked wafers T, are moved into or out of the loading / unloading station 401 of the substrate processing system 400. Then, on the cassette mounting stage 410, the cassettes Cw, Cs, and Ct are arbitrarily arranged in a row in the Y-axis direction.

[0212] The above embodiments are described in the case where the wafer W to be processed is directly bonded to the supporting wafer S. However, the wafer W to be processed and the supporting wafer S can also be bonded by a bonding agent.

[0213] The above description pertains to embodiments of the present invention, but the present invention is not limited to these embodiments. Those skilled in the art will readily conceive of various variations or modifications within the scope of the technical concept described in the claims, and will understand that such embodiments naturally also fall within the technical scope of the present invention. [Simplified Explanation of the Diagram]

[0013] [Fig. 1] is a top view schematically showing the schematic structure of the substrate processing system of the first embodiment. [Fig. 2] is a side view showing the schematic structure of the laminated wafer. [Fig. 3] is a side view showing the schematic structure of the modifier layer forming apparatus. [Fig. 4] is a longitudinal cross-sectional view showing the state of forming a modifier layer on the processed wafer. [Fig. 5] is a top view showing the state of forming a modifier layer on the processed wafer. [Fig. 6] is a side view showing the schematic structure of the grinding unit of the processing apparatus. [Fig. 7] (a) to (c) are explanatory diagrams showing the state of the processed wafer in the main steps of the wafer processing of the first embodiment. [Fig. 8] (a) to (d) are explanatory diagrams showing the state of the processed wafer in the main steps of the wafer processing of a variant embodiment of the first embodiment. [Fig. 9] is a top view schematically showing the schematic structure of the substrate processing system of the second embodiment. [Fig. 10] is a side view showing the schematic structure of the perimeter removal device. [Fig. 11] (a) to (e) are explanatory diagrams showing the state of the wafer being processed in the main steps of the wafer processing in the second embodiment. [Fig. 12] (a) to (d) are explanatory diagrams showing the state of the wafer being processed in the main steps of the wafer processing in another embodiment. [Fig. 13] (a) and (b) are explanatory diagrams showing the state of the wafer being processed in the main steps of the wafer processing in another embodiment. [Fig. 14] (a) to (d) are longitudinal sectional views showing the state of forming a modifier layer on the wafer being processed in another embodiment. [Fig. 15] (a) to (c) are explanatory diagrams showing the state of forming a modifier layer on the wafer being processed in another embodiment. [Fig. 16] is a top view showing the state of forming a modifier layer on the wafer being processed in another embodiment. [Fig. 17] is a top view showing a state in which a modifier layer is formed on a wafer being processed in another embodiment. [Fig. 18] is a top view showing a state in which a modifier layer is formed on a wafer being processed in another embodiment. [Fig. 19] (a) and (b) are longitudinal sectional views showing a state in which a modifier layer is formed on a wafer being processed in another embodiment. [Fig. 20] is a side view showing a schematic structure of an interface processing apparatus. [Fig. 21] is a top view showing a state in which a modifier trench is formed on a wafer being processed in another embodiment. [Fig. 22] is a top view showing a state in which a modifier surface is formed on a wafer being processed in another embodiment. [Fig. 23] (a) to (e) are explanatory diagrams showing the state of the wafer being processed in the main steps of wafer processing in another embodiment. [Fig. 24] is a side view showing a schematic structure of an interface processing apparatus. [Fig. 25] is a side view showing a schematic structure of a processing apparatus. [Figure 26] is a longitudinal cross-sectional view of a sample in which a modified surface is formed inside the processed wafer in another embodiment. [Figure 27] is an explanatory diagram of a longitudinal cross-section of a sample forming the modified surface shown in Figure 26.[Fig. 28] is a longitudinal cross-sectional view showing a state in which a modified surface is formed on the element layer of the processed wafer in another embodiment. [Fig. 29] (a) to (c) are explanatory diagrams showing the longitudinal cross-sections of the state in which the modified surface shown in Fig. 28 is formed. [Fig. 30] (a) to (e) are explanatory diagrams showing the state of the processed wafer in the main steps of wafer processing in another embodiment. [Fig. 31] is a top view showing a state in which the center of the processed wafer is offset in a stacked wafer. [Fig. 32] (a) and (b) are explanatory diagrams showing when the modified layer is located radially inward than the inner periphery of the modified surface. [Fig. 33] (a) and (b) are explanatory diagrams showing when the modified layer is located radially outward than the inner periphery of the modified surface. [Fig. 34] is a side view showing a schematic structure of the processing apparatus. [Figure 35] is a top view schematically showing the general structure of the substrate processing system of the third embodiment.

Claims

1. A substrate processing system for processing a laminated substrate formed by bonding a first substrate and a second substrate, comprising: a modifier layer forming apparatus for irradiating a laser light from the processing surface side of the first substrate in the laminated substrate to form a modifier layer inside the first substrate along the boundary between a peripheral portion and a central portion of the first substrate that is to be removed; and a processing apparatus for reducing the thickness of the first substrate from the processing surface side while forming a crack in the modifier layer, and peeling and removing the peripheral portion from the first substrate with the modifier layer as a reference point.

2. The substrate processing system as claimed in claim 1, wherein the modified layer forming apparatus forms another modified layer inside the first substrate, radially outward from the boundary, for fragmenting the peripheral portion when the processing apparatus removes the peripheral portion.

3. The substrate processing system as claimed in claim 2, wherein the modified layer forming apparatus controls the size of the removed peripheral fragments by controlling the upper height of the crack extending from the modified layer.

4. The substrate processing system as described in claim 2 or 3, wherein the modified layer forming apparatus forms a radial modified layer extending radially outward from the boundary inside the first substrate.

5. The substrate processing system as described in claim 2 or 3, wherein the modified layer forming apparatus forms a plurality of annular segmented modified layers in a direction concentric with the modified layer, radially outward from the boundary.

6. The substrate processing system as claimed in claim 2 or 3, wherein the modified layer forming apparatus forms a segmented modified layer that appears spiral in plan view on the radially outer side from the boundary.

7. The substrate processing system as described in any one of claims 1 to 3, wherein the modified layer forming apparatus disperses the concentrated light of the laser light to form the modified layer in such a way that the lower end of the modified layer is located below the target surface of the first substrate after processing by the processing apparatus, and a crack extending from the modified layer reaches the unprocessed surface opposite to the processed surface.

8. The substrate processing system as described in any one of claims 1 to 3, wherein the modified layer forming apparatus forms the modified layer in such a manner that the lower end of the modified layer is located above the target surface of the first substrate after processing by the processing apparatus, and a crack extending from the modified layer reaches the unprocessed surface opposite to the processed surface, but does not reach the processed surface.

9. The substrate processing system as described in any one of claims 1 to 3, wherein the modified layer forming apparatus forms the modified layer in accordance with the notch shape by performing relative motion control on the first substrate and the laser light.

10. The substrate processing system according to any one of claims 1 to 3, wherein a component layer and a bonding layer are formed on the first substrate; at least one bonding layer is formed on the second substrate; and in the laminated substrate, the bonding layer of the first substrate and the bonding layer of the second substrate are bonded by hydrogen bonding.

11. The substrate processing system as claimed in claim 10, wherein a component layer is formed on the second substrate.

12. The substrate processing system as described in any one of claims 1 to 3, wherein the processing apparatus, while the first substrate is in contact with a portion of the arc of the grinding stone, rotates the first substrate and the grinding stone to grind the processed surface; and the rotation direction of the grinding stone relative to the rotating first substrate is rotated from the outside to the inside of the first substrate.

13. The substrate processing system as described in any one of claims 1 to 3, wherein the processing apparatus, while the first substrate is in contact with a portion of the arc of the grinding stone, rotates the first substrate and the grinding stone to grind the processed surface; and the rotation direction of the grinding stone relative to the rotating first substrate is rotated from the inside to the outside of the first substrate.

14. The substrate processing system according to any one of claims 1 to 3, wherein the processing apparatus comprises at least: a rough grinding unit for rough grinding the processing surface; and a fine grinding unit for fine grinding the processing surface; and removing the peripheral portion prior to the fine grinding.

15. The substrate processing system as described in any one of claims 1 to 3, wherein the processing apparatus grinds the processing surface and sprays a high-pressure water jet from the inside to the outside of the first substrate toward the periphery during the grinding.

16. The substrate processing system according to any one of claims 1 to 3 further comprises: a grinding apparatus, wherein the processing surface is ground after being ground in the processing apparatus.

17. A substrate processing system as described in any one of claims 1 to 3, wherein the modified layer forming apparatus irradiates the laser light from the processing surface side of the first substrate in the laminated substrate held by the holding portion holding the second substrate, and the processing apparatus reduces the thickness of the first substrate in the laminated substrate held by the second holding portion holding the second substrate from the processing surface side, and the substrate processing system further comprises a transport device for transporting the laminated substrate from the holding portion to the second holding portion.

18. A substrate processing system as described in any one of claims 1 to 3, wherein the modified layer forming apparatus comprises: a holding portion for holding the second substrate in the laminated substrate; a rotating mechanism for rotating the holding portion; a modified portion for irradiating laser light from the processing surface side of the first substrate in the laminated substrate held by the holding portion; and a lifting mechanism for lifting the modified portion; the modified layer forming apparatus performs the following steps: while rotating the holding portion, irradiating the modified portion with laser light to form the modified layer inside the first substrate; and then, while the rotation of the holding portion continues, stopping the irradiation of laser light from the modified portion, then lifting the modified portion and irradiating the modified portion with laser light to form a second modified layer inside the first substrate.

19. A substrate processing method for processing a laminated substrate formed by bonding a first substrate and a second substrate, comprising the following steps: irradiating a laser light from the processing surface side of the first substrate in the laminated substrate, and forming a modified layer inside the first substrate along the boundary between a peripheral portion and a central portion of the first substrate that is to be removed; and while performing a processing process that reduces the thickness of the first substrate from the processing surface side, forming a crack in the modified layer, and peeling and removing the peripheral portion from the first substrate with the modified layer as a reference point.

20. The substrate processing method as described in claim 19 further comprises the following step: forming, inside the first substrate, a modified layer extending radially outward from the boundary to fragment the peripheral portion when it is removed.

21. The substrate processing method as described in claim 20, wherein, during the formation of the modified layer, the size of the removed peripheral fragments is controlled by controlling the upper height of the crack extending from the modified layer.

22. The substrate processing method as described in claim 20 or 21, wherein, when forming the other modified layer, a radial modified layer extending radially outward from the boundary is formed inside the first substrate.

23. The substrate processing method as described in claim 20 or 21, wherein, when forming the other modified layer, a plurality of annular segmented modified layers are formed radially outward from the boundary in a direction concentric with the modified layer.

24. The substrate processing method as described in claim 20 or 21, wherein, when forming the other modified layer, a segmented modified layer that appears spiral in plan view is formed on the radially outer side from the boundary.

25. A substrate processing method as described in any one of claims 19 to 21, wherein when forming the modified layer, the concentrated light of the laser light is diffused, and the modified layer is formed in such a way that the lower end of the modified layer is located below the target surface of the processed first substrate, and a crack extending from the modified layer reaches the unprocessed surface opposite to the processed surface.

26. The substrate processing method according to any one of claims 19 to 21, wherein when forming the modified layer, the modified layer is formed in such a way that the lower end of the modified layer is located above the target surface of the processed first substrate, and a crack extending from the modified layer reaches the unprocessed surface opposite to the processed surface, but does not reach the processed surface.

27. The substrate processing method according to any one of claims 19 to 21, wherein, in forming the modified layer, the modified layer is formed in accordance with the notch shape by performing relative motion control on the first substrate and the laser light.

28. A substrate processing method as described in any one of claims 19 to 21, wherein a component layer and a bonding layer are formed on the first substrate; at least one bonding layer is formed on the second substrate; and in the laminated substrate, the bonding layer of the first substrate and the bonding layer of the second substrate are bonded by hydrogen bonding.

29. The substrate processing method as described in claim 28, wherein a component layer is formed on the second substrate.

30. A substrate processing method as described in any one of claims 19 to 21, wherein in the processing, while the first substrate is in contact with a portion of the arc of a grinding stone, the first substrate and the grinding stone are rotated to grind the processed surface; the rotation direction of the grinding stone relative to the rotating first substrate is rotated from the outside to the inside of the first substrate.

31. A substrate processing method as described in any one of claims 19 to 21, wherein in the processing, while the first substrate is in contact with a portion of the arc of a grinding stone, the first substrate and the grinding stone are rotated to grind the processed surface; the rotation direction of the grinding stone relative to the rotating first substrate is rotated from the inside to the outside of the first substrate.

32. A substrate processing method as described in any one of claims 19 to 21, wherein the processing comprises at least the following steps: rough grinding the processed surface; and fine grinding the processed surface; and removing the peripheral portion prior to the fine grinding.

33. A substrate processing method as described in any one of claims 19 to 21, wherein the processing surface is ground and a high-pressure water jet is sprayed from the inside to the outside of the first substrate toward the periphery during the grinding process.

34. The substrate processing method according to any one of claims 19 to 21 further comprises the following steps: after grinding the processing surface in the processing, the processing surface is polished.

35. A substrate processing method as described in any one of claims 19 to 21, wherein, during the formation of the modified layer, the laser light is irradiated from the processing surface side of the first substrate in the laminated substrate held by the holding portion holding the second substrate, and during the processing, the thickness of the first substrate in the laminated substrate held by the second holding portion holding the second substrate is reduced from the processing surface side, and the laminated substrate is transported from the holding portion to the second holding portion by a transport device.

36. The substrate processing method according to any one of claims 19 to 21 further comprises the following steps: while rotating the holding portion holding the second substrate in the laminated substrate, irradiating the modified portion with laser light to form the modified layer inside the first substrate; and then, while the rotation of the holding portion continues, stopping the irradiation of the laser light from the modified portion, then raising the modified portion and irradiating the modified portion with laser light to form the second modified layer inside the first substrate.

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