Substrate Processing Method and Substrate Processing System

Abstract

To appropriately remove a peripheral portion of one substrate in a polymerized substrate in which substrates are bonded to each other.SOLUTION: A substrate processing method for processing a substrate includes the steps of: preparing a polymerized substrate in which a first substrate and a second substrate are bonded; performing modified layer forming processing of forming a modified layer inside the first substrate along a boundary between a peripheral portion to be removed and a central portion of the first substrate; performing modification processing inside the first substrate near an unprocessed surface of the first substrate on the side where the first substrate and the second substrate are bonded, and radially outward from the boundary; and removing the peripheral portion starting from the modified layer.SELECTED DRAWING: Figure 26

Description

Technical Field

[0001] (Cross - reference to related applications) This application claims priority 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, and incorporates their contents herein by reference.

[0002] The present invention relates to a substrate processing method and a substrate processing system.

Background Art

[0003] In recent years, in the manufacturing process of semiconductor devices, a semiconductor wafer (hereinafter referred to as a wafer) having devices such as a plurality of electronic circuits formed on its surface is thinned by grinding the back surface of the wafer. If the thinned wafer is transported as it is or subsequent processing is performed, the wafer may warp or crack. Therefore, in order to reinforce the wafer, for example, the wafer is attached to a support substrate.

[0004] By the way, usually, the peripheral portion of the wafer is chamfered. However, when the wafer is ground as described above, the peripheral portion of the wafer becomes a sharp shape (so - called knife - edge shape). Then, chipping may occur at the peripheral portion of the wafer, and the wafer may be damaged. Therefore, so - called edge trimming, which cuts the peripheral portion of the wafer in advance before the grinding process, is performed.

[0005] For example, Patent Document 1 discloses a vertical - axis type end - face grinding device as an apparatus for performing edge trimming. When grinding the peripheral portion of the wafer using this end - face grinding device, first, the wafer with the support substrate attached is fixed to a table, and the table is rotated around an axis parallel to the vertical axis. Then, after rotating the spindle to rotate the wheel which is a grinding tool, the spindle is moved in the vertical direction to bring the grinding surface of the wheel into contact with the wafer, and the peripheral portion of the wafer is ground.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

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

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to appropriately remove the peripheral portion of one substrate in a polymer substrate in which substrates are joined together.

Means for Solving the Problems

[0009] One aspect of the present invention for solving the above problems is a substrate processing method for processing a substrate, comprising: On which a plurality of films are formed on the non-processed surface a step of preparing a polymer substrate in which a first substrate and a second substrate are joined; performing a modified layer forming process for forming a modified layer inside the first substrate along the boundary between the peripheral portion and the central portion of the first substrate to be removed; in the peripheral portion, said non- performing a modification process radially outward from the boundary inside the first substrate near the processing surface; and removing the peripheral portion with the modified layer as a base point.

[0010] One aspect of the present invention from another perspective is On which a plurality of films are formed on the non-processed surface a substrate processing system for processing a polymer substrate in which a first substrate and a second substrate are joined, forming a modified layer inside the first substrate along the boundary between the peripheral portion and the central portion of the first substrate to be removed; and in the peripheral portion, the first substratesaid non- A processing apparatus that performs a modification process radially outward from the boundary inside the first substrate near the processed surface, a peripheral edge removing apparatus that removes the peripheral edge portion based on the modified layer, and a transfer apparatus that transfers the polymerized substrate between the processing apparatus and the peripheral edge removing apparatus.

Advantages of the Invention

[0011] According to one aspect of the present invention, in a polymerized substrate in which substrates are joined together, the peripheral edge portion of one substrate can be appropriately removed.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Figure 30

Figure 31

Figure 32

Figure 33

Figure 34

Figure 35

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0014] First, a first embodiment of the present invention will be described. FIG. 1 is a plan view schematically showing an outline of the configuration of a substrate processing system 1 according to the first embodiment. In the following, in order to clarify the positional relationship, an X-axis direction, a Y-axis direction, and a Z-axis direction orthogonal to each other are defined, and the positive direction of the Z-axis is the vertically upward direction.

[0015] In the substrate processing system 1, as shown in FIG. 2, a wafer W to be processed as a first substrate and a support wafer S as a second substrate are bonded to form a polymerized wafer T as a polymerized substrate, and further the wafer W to be processed is thinned. Hereinafter, in the wafer W to be processed, the surface to be processed (the surface opposite to the surface bonded to the support wafer S) is referred to as "processing surface Wg", and the surface opposite to the processing surface Wg is referred to as "non-processing surface Wn". Further, in the support wafer S, the surface bonded to the wafer W to be processed is referred to as "bonding surface Sj", and the surface opposite to the bonding surface Sj is referred to as "non-bonding surface Sn".

[0016] The wafer W to be processed is a semiconductor wafer such as a silicon wafer, for example, and a plurality of devices are formed on the non-processing surface Wn. Note that the peripheral portion of the wafer W to be processed is chamfered, and the cross section of the peripheral portion becomes thinner toward the tip.

[0017] The support wafer S is a wafer that supports the wafer W to be processed. Further, the support wafer S functions as a protective material that protects the devices on the non-processing surface Wn of the wafer W to be processed. Note that when a plurality of devices are formed on the bonding surface Sj of the support wafer S, a device layer (not shown) is formed on the bonding surface Sj in the same manner as the wafer W to be processed.

[0018] As shown in FIG. 1, the substrate processing system 1 has a configuration in which, for example, a loading / unloading station 2 into which cassettes Cw, Cs, Ct capable of accommodating a plurality of wafers W to be processed, a plurality of support wafers S, and a plurality of polymerized wafers T are respectively loaded / unloaded, and a processing station 3 provided with various processing apparatuses for performing predetermined processing on the wafer W to be processed, the support wafer S, and the polymerized wafer T are integrally connected.

[0019] The loading / unloading station 2 is provided with a cassette mounting table 10. In the illustrated example, a plurality of, for example, four cassettes Cw, Cs, Ct can be mounted in a row in the X-axis direction on the cassette mounting table 10. Note that the number of cassettes Cw, Cs, Ct mounted on the cassette mounting table 10 is not limited to the present embodiment and can be arbitrarily determined.

[0020] In the loading / unloading station 2, a wafer transfer area 20 is provided adjacent to the cassette mounting table 10. In the wafer transfer area 20, a wafer transfer device 22 that is movable on a transfer path 21 extending in the X-axis direction is provided. The wafer transfer device 22 has, for example, two transfer arms 23, 23 that hold and transfer the bonded wafers T. Each transfer arm 23 is configured to be movable in the horizontal direction, vertical direction, around the horizontal axis, and around the vertical axis. Note that the configuration of the transfer arm 23 is not limited to this embodiment and can take any configuration.

[0021] In the processing station 3, on the positive Y-axis side of the wafer transfer area 20, a bonding device 30 for bonding the wafer to be processed W and the support wafer S, a modified layer forming device 31 for forming a modified layer inside the wafer to be processed W, and a processing device 32 for grinding and processing the processed surface Wg of the wafer to be processed W are arranged side by side from the negative X-axis side to the positive direction side. Note that the number and arrangement of the bonding device 30, the modified layer forming device 31, and the processing device 32 are not limited to this embodiment and can be arbitrarily determined. In this embodiment, the processing device 32 functions as the peripheral removal device of the present invention.

[0022] The above substrate processing system 1 is provided with a control device 40. The control device 40 is, for example, a computer and has a program storage unit (not shown). In the program storage unit, a program for controlling the processing of the wafer to be processed W, the support wafer S, and the bonded wafer T in the substrate processing system 1 is stored. In addition, in the program storage unit, a program for controlling the operation of the drive systems of the above various processing devices and transfer devices, etc., to realize the wafer processing described later in the substrate processing system 1 is also stored. Note that the program is recorded, for example, on a computer-readable storage medium H such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magneto-optical disk (MO), memory card, etc., and may be installed from the storage medium H to the control device 40.

[0023] Next, the bonding apparatus 30, the modification layer forming apparatus 31, and the processing apparatus 32 will be described.

[0024] The bonding apparatus 30 bonds the non-processed surface Wn of the wafer W to be processed and the bonding surface Sj of the support wafer S by van der Waals forces and hydrogen bonds (intermolecular forces). At the time of this bonding, it is preferable that the non-processed surface Wn and the bonding surface Sj are each modified and hydrophilized. Specifically, when modifying the non-processed surface Wn and the bonding surface Sj, for example, in a reduced-pressure atmosphere, the processing gas, oxygen gas or nitrogen gas, is excited, plasmaized, and ionized. This oxygen ion or nitrogen ion is irradiated onto the non-processed surface Wn and the bonding surface Sj, and the non-processed surface Wn and the bonding surface Sj are plasma-treated and activated. Further, pure water is supplied to the non-processed surface Wn and the bonding surface Sj thus modified to hydrophilize the non-processed surface Wn and the bonding surface Sj. Note that the configuration of the bonding apparatus 30 is arbitrary, and a known bonding apparatus can be used.

[0025] The modification layer forming apparatus 31 irradiates a laser beam into the wafer W to be processed to form a modification layer. As shown in FIG. 3, the modification layer forming apparatus 31 has a chuck 100 as a holding unit that holds the polymerized wafer T in a state where the wafer W to be processed is on the upper side and the support wafer S is on the lower side. The chuck 100 is configured to be movable in the X-axis direction and the Y-axis direction by a moving mechanism 101. The moving mechanism 101 is configured by a general precision XY stage. Further, the chuck 100 is configured to be rotatable about a vertical axis by a rotation mechanism 102.

[0026] Above the chuck 100, a laser head 103 as a modification part for irradiating the inside of the wafer W to be processed with laser light is provided. The laser head 103 is high-frequency pulsed laser light oscillated from a laser light oscillator (not shown), and condenses and irradiates laser light having a wavelength that is transmissive to the wafer W to be processed at a predetermined position inside the wafer W to be processed. As a result, as shown in FIG. 4, the portion where the laser light L is condensed inside the wafer W to be processed is modified, and a modified layer M is formed. The modified layer M extends in the plate thickness direction and has an aspect ratio that is vertically long. As shown in FIG. 3, the laser head 103 may be configured to be movable in the X-axis direction and the Y-axis direction by a movement mechanism 104. The movement mechanism 104 is configured by a general precision XY stage. Further, the laser head 103 may be configured to be movable in the Z-axis direction by a lifting mechanism 105.

[0027] In the modification layer forming apparatus 31, first, after holding the polymerization wafer T with the chuck 100, the chuck 100 is moved horizontally by the movement mechanism 101 to center the polymerization wafer T, and the laser head 103 is positioned directly above a predetermined position of the polymerization wafer T (wafer W to be processed) by the movement mechanism 104. Then, while rotating the chuck 100 by the rotation mechanism 102, the laser head 103 irradiates the inside of the wafer W to be processed with the laser light L to form an annular modified layer M on the wafer W to be processed as shown in FIG. 5. In order to perform the above-described position adjustment, the modification layer forming apparatus 31 may be provided with a camera (not shown) for imaging the position of the polymerization wafer T.

[0028] The formation position of the modified layer M on the wafer W to be processed will be described in detail. In the substrate processing system 1, the processing surface Wg of the wafer W to be processed bonded to the support wafer S is ground. However, in order to avoid the formation of a knife edge at the peripheral edge of the wafer W to be processed after grinding, the peripheral edge is removed before grinding. The modified layer M serves as a reference point during this peripheral edge removal, and as shown in FIG. 5, it is formed in an annular shape along the boundary between the peripheral edge We and the central portion Wc of the wafer W to be processed that are to be removed. Note that the peripheral edge We is, for example, in the range of 0.5 mm to 2.0 mm in the radial direction from the end of the wafer W to be processed and includes a chamfered portion.

[0029] Also, as shown in FIG. 4, the lower end of the modified layer M is located above the target surface (dotted line in FIG. 4) of the wafer W to be processed after grinding. That is, the distance H1 between the lower end of the modified layer M and the non-processing surface Wn of the wafer W to be processed is greater than the target thickness H2 of the wafer W to be processed after grinding. The distance H1 is arbitrary, but is, for example, 5 μm to 10 μm greater than the target thickness H2. In such a case, the modified layer M does not remain on the wafer W to be processed after grinding.

[0030] In the modified layer forming apparatus 31 of the present embodiment, the chuck 100 is moved in the horizontal direction. However, the laser head 103 may be moved in the horizontal direction, or both the chuck 100 and the laser head 103 may be moved in the horizontal direction. Also, although the chuck 100 is rotated, the laser head 103 may be rotated.

[0031] The processing apparatus 32 grinds and processes the processing surface Wg of the wafer W to be processed. Specifically, the processing apparatus 32 includes, for example, a grinding unit that grinds the processing surface Wg and a cleaning unit that cleans the processing surface Wg of the wafer W to be processed and the non-bonding surface Sn of the support wafer S.

[0032] As shown in FIG. 6, the grinding unit 110 has a chuck 111 that holds the polymerized wafer T in a state where the wafer W to be processed is on the upper side and the support wafer S is on the lower side. The chuck 111 is configured to be rotatable about a vertical axis by a rotation mechanism (not shown).

[0033] Above the chuck 111, a grinding wheel 112 with an annular shape is provided. A drive unit 114 is provided on the grinding wheel 112 via a spindle 113. The drive unit 114 incorporates, for example, a motor (not shown), rotates the grinding wheel 112, and moves it in the vertical and horizontal directions.

[0034] And in the grinding unit 110, with a state where a part of the arc of the processed wafer W held by the chuck 111 is in contact with the grinding wheel 112, the chuck 111 and the grinding wheel 112 are rotated respectively, thereby grinding the processed surface Wg of the processed wafer W.

[0035] Next, the wafer processing performed using the substrate processing system 1 configured as described above will be explained.

[0036] First, a cassette Cw storing a plurality of processed wafers W and a cassette Cs storing a plurality of support wafers S are placed on the cassette mounting table 10 of the loading / unloading station 2.

[0037] Next, the processed wafer W in the cassette Cw is taken out by the wafer transfer device 22 and transferred to the bonding device 30. Subsequently, the support wafer S in the cassette Cs is also taken out by the wafer transfer device 22 and transferred to the bonding device 30. In the bonding device 30, with the processed wafer W arranged on the upper side and the support wafer S on the lower side, they are bonded by van der Waals forces and intermolecular forces to form a polymerized wafer T. At this time, if the non-processed surface Wn of the processed wafer W and the bonding surface Sj of the support wafer S are activated by, for example, plasma oxygen ions or nitrogen ions, appropriate van der Waals forces and intermolecular forces will occur.

[0038] Next, the polymerized wafer T is conveyed by the wafer transfer device 22 to the modification layer forming device 31. The polymerized wafer T conveyed to the modification layer forming device 31 is delivered to and held by the chuck 100. Thereafter, the chuck 100 is horizontally moved by the moving mechanism 101 to center the polymerized wafer T, and position adjustment is performed so that the laser head 103 is positioned directly above a predetermined position of the polymerized wafer T (the wafer to be processed W). This predetermined position is the boundary between the peripheral edge portion We and the central portion Wc of the wafer to be processed W. Thereafter, while rotating the chuck 100 by the rotation mechanism 102, the laser head 103 irradiates the inside of the wafer to be processed W with laser light L to form an annular modification layer M inside the wafer to be processed W as shown in FIG. 7(a). Note that the formation position of this modification layer M is as described with reference to FIGS. 4 and 5 above.

[0039] Next, the polymerized wafer T is conveyed by the wafer transfer device 22 to the processing device 32. The polymerized wafer T conveyed to the processing device 32 is delivered to and held by the chuck 111. Thereafter, as shown in FIG. 7(b), while bringing a part of the arc of the wafer to be processed W into contact with the grinding wheel 112 and lowering the grinding wheel 112, the chuck 111 and the grinding wheel 112 are rotated respectively to grind the processed surface Wg of the wafer to be processed W.

[0040] During the grinding of the processed surface Wg, cracks C progress in the thickness direction from the modification layer M inside the wafer to be processed W and reach the processed surface Wg and the non-processed surface Wn. Since the wafer to be processed W has a single crystal of silicon, the cracks C progress substantially linearly. Also, the cracks C are formed in an annular shape in plan view. Note that the cracks C may progress when the modification layer M is formed in the modification layer forming device 31. In other words, the timing at which the cracks C are formed may be during the grinding of the processed surface Wg in the processing device 32 or when the modification layer M is formed in the modification layer forming device 31.

[0041] Further, as the grinding of the processed surface Wg progresses, as shown in FIG. 7(c), the peripheral edge We of the wafer W to be processed peels off and is removed based on the modified layer M and the crack C. At this time, as described above, since the crack C progresses substantially linearly, the outer surface of the wafer W to be processed after removal can be made flat with few irregularities. Further, as described above, since the lower end of the modified layer M is located above the target surface of the wafer W to be processed after grinding, the modified layer M is removed during the grinding of the processed surface Wg. The modified layer M is amorphized and has low strength. In this regard, in the present embodiment, since the modified layer M does not remain on the wafer W to be processed after grinding, high strength can be ensured.

[0042] In this way, in the modified layer forming apparatus 31, while the peripheral edge We is removed, the processed surface Wg of the wafer W to be processed is ground to the target thickness.

[0043] Thereafter, the polymerized wafer T that has undergone all the processes is transported by the wafer transport device 22 to the cassette Ct on the cassette mounting table 10. Thus, a series of wafer processes in the substrate processing system 1 are completed.

[0044] Next, a modification of the first embodiment will be described. In the above, after the wafer W to be processed and the support wafer S are joined by the joining device 30, the modified layer M is formed inside the wafer W to be processed by the modified layer forming device 31. In this modification, however, this order is reversed.

[0045] That is, in the substrate processing system 1, first, the wafer W to be processed in the cassette Cw is taken out by the wafer transport device 22 and transported to the modified layer forming device 31. In the modified layer forming device 31, as shown in FIG. 8(a), the modified layer M is formed at a predetermined position inside the wafer W to be processed.

[0046] Incidentally, in parallel with the formation of the modified layer M by the modified layer forming device 31, the support wafer S in the cassette Cs is taken out by the wafer transport device 22 and transported to the joining device 30.

[0047] Next, the wafer to be processed W is transported to the bonding device 30 by the wafer transfer device 22. In the bonding device 30, as shown in FIG. 8(b), the wafer to be processed W and the support wafer S are bonded to form a polymerized wafer T.

[0048] Next, the polymerized wafer T is transported to the processing device 32 by the wafer transfer device 22. In the processing device 32, as shown in FIG. 8(c), while bringing a part of the arc of the grinding wheel 112 into contact with the processing surface Wg of the wafer to be processed W, the grinding wheel 112 is lowered and the chuck 111 and the grinding wheel 112 are rotated respectively, thereby grinding the processing surface Wg of the wafer to be processed W. Then, as shown in FIG. 8(d), while the peripheral portion We is removed, the processing surface Wg of the wafer to be processed W is ground to the target thickness.

[0049] Thereafter, the polymerized wafer T that has undergone all the processes is transported to the cassette Ct on the cassette mounting table 10 by the wafer transfer device 22. Thus, a series of wafer processes in the substrate processing system 1 are completed.

[0050] According to the above-described first embodiment and modification, the following effects can be obtained. In the following description, it will be described in comparison with the case where the peripheral portion of the wafer to be processed is ground and removed with a wheel (grinding tool) as in the prior art. Conventionally, there is a case where the peripheral portion of the wafer to be processed is removed using a blade (grinding tool), but in this case, there are also the same problems as when using a wheel.

[0051] When the wafer to be processed and the support wafer are bonded and then, as in the prior art, that is, as described in Patent Document 1 mentioned above, the peripheral portion of the wafer to be processed in the polymerized wafer is ground and removed with a wheel, for example, due to various factors such as tolerances, the vertical movement of the wheel may not be appropriately controlled, and there is a risk of grinding to the surface of the support wafer. On the other hand, in this embodiment, by forming the modified layer M inside the wafer to be processed W, the peripheral portion We can be removed based on the modified layer M and the crack C. In such a case, the bonding surface Sj of the support wafer S is not damaged by grinding or the like.

[0052] Before bonding the wafer to be processed and the support wafer, when the peripheral portion of the wafer to be processed is ground and removed with a wheel as in the prior art, particles are generated by the grinding, and there is a risk that the particles will adhere to the devices on the wafer to be processed. In contrast, in the present embodiment, since the peripheral portion We is peeled off and removed based on the modified layer M and the crack C formed inside the wafer W to be processed, no particles are generated. Therefore, even when the wafer W to be processed before bonding is processed as in the modification shown in FIG. 8 in particular, the devices on the non-processed surface Wn are not contaminated.

[0053] When using a wheel as in the prior art, there is a limit to the horizontal position adjustment of the wheel, and variations of about several micrometers occur. Then, variations also occur in the width (trim width) of the peripheral portion ground and removed by the wheel, and the processing accuracy is not good. In contrast, in the present embodiment, since the modified layer M is formed inside the wafer W to be processed using a laser, high accuracy of, for example, less than 1 μm can be ensured. For this reason, the accuracy of the width (trim width) of the peripheral portion We removed based on the modified layer M is also improved.

[0054] When using a wheel as in the prior art, since the wheel is lowered to grind the peripheral portion, there is a limit to the rotational speed of the chuck that holds the wafer to be processed, and it takes time to remove the peripheral portion. In contrast, in the present embodiment, since the modified layer M is formed inside the wafer W to be processed using a high-frequency laser, the rotational speed of the chuck 100 can be increased, and the processing can be performed in an extremely short time. Therefore, the throughput of wafer processing can be improved.

[0055] When using a wheel as in the prior art, since the wheel wears out, regular replacement is required. Also, in grinding using a wheel, grinding water is used, and waste liquid treatment is also required. For this reason, running costs are high. In contrast, in this embodiment, the laser head 103 itself does not deteriorate over time, and the maintenance frequency can be reduced. Also, since it is a dry process using a laser, grinding water and wastewater treatment are not required. Therefore, the running cost can be reduced.

[0056] Further, on the wafer W to be processed, which is a semiconductor wafer, a notch is formed to indicate the direction of the crystal orientation. However, it was difficult to leave the shape of this notch as it was in the removal of the peripheral portion We only by a conventional blade. In contrast, in this embodiment, for example, in the modification layer forming apparatus 31, by relatively controlling the operation of the wafer W to be processed and the laser beam, the modification layer M can be formed according to the shape of the notch, and the peripheral portion We can be easily removed while leaving the shape of the notch.

[0057] In addition, in the above embodiment, as a method for efficiently removing the peripheral portion We during the grinding of the processed surface Wg, the rotation direction of the grinding wheel 112 is rotated from the outside to the inside of the wafer W to be processed, or the rotation direction of the grinding wheel 112 is rotated from the inside to the outside of the wafer W to be processed. Thus, the rotation direction of the grinding wheel 112 can be changed according to the type of the wafer W to be processed and the processing step.

[0058] Also, during the grinding of the processed surface Wg, high-pressure water may be applied to the peripheral portion We from the inside to the outside of the wafer W to be processed to efficiently remove (or blow off) the peripheral portion We.

[0059] In addition, in the modification example of the above first embodiment, the formation of the modification layer M in the modification layer forming apparatus 31, the bonding of the wafer W to be processed and the support wafer S in the bonding apparatus 30, and the removal of the peripheral portion We in the processing apparatus 32 are sequentially performed. However, the order of wafer bonding and removal of the peripheral portion We may be reversed. That is, the formation of the modification layer M in the modification layer forming apparatus 31, the removal of the peripheral portion We in the processing apparatus 32, and the bonding of the wafer W to be processed and the support wafer S in the bonding apparatus 30 may be sequentially performed.

[0060] Next, a second embodiment of the present invention will be described. FIG. 9 is a plan view schematically showing the configuration of a substrate processing system 200 according to the second embodiment. The substrate processing system 200 further includes a peripheral removal device 210 for removing the peripheral edge We of the wafer W to be processed in the configuration of the substrate processing system 1 of the first embodiment. The peripheral removal device 210 is disposed, for example, between the modification layer forming device 31 and the processing device 32.

[0061] The peripheral removal device 210 forms a modification layer M on the wafer W to be processed by the modification layer forming device 31, and then applies a force outside the modification layer M to remove the peripheral edge We. That is, in the first embodiment, the peripheral edge We was removed during grinding of the processing surface Wg of the wafer W to be processed by the processing device 32, but in the second embodiment, the removal of the peripheral edge We is performed by the peripheral removal device 210.

[0062] As shown in FIG. 10, the peripheral removal device 210 has a chuck 211 that holds the polymerized wafer T in a state where the wafer W to be processed is on the upper side and the support wafer S is on the lower side. The chuck 211 is configured to be rotatable about a vertical axis by a rotation mechanism (not shown).

[0063] Above the chuck 211, there is an annular grinding wheel 212. The grinding wheel 212 is provided with a drive unit 214 via a spindle 213. The drive unit 214 incorporates, for example, a motor (not shown), rotates the grinding wheel 212, and moves it in the vertical and horizontal directions. In this embodiment, a grinding wheel 212 is used, but the present invention is not limited thereto, and for example, a blade may be used.

[0064] Then, in the peripheral removal device 210, while the peripheral portion We of the wafer W held by the chuck 211 is brought into contact with a part 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. Due to this impact, the peripheral portion We is removed. In such a case, by forming the modified layer M, the accuracy of the removal surface of the wafer W can be achieved.

[0065] Next, the wafer processing performed using the substrate processing system 200 configured as described above will be explained. In this embodiment, detailed explanations for the same processes as in the first embodiment will be omitted.

[0066] First, the wafer transfer device 22 takes out the wafer W to be processed in the cassette Cw and transfers it to the modified layer forming device 31. In the modified layer forming device 31, as shown in FIG. 11(a), a modified layer M is formed at a predetermined position inside the wafer W to be processed.

[0067] Note that in parallel with forming the modified layer M in the modified layer forming device 31, the wafer transfer device 22 takes out the support wafer S in the cassette Cs and transfers it to the bonding device 30.

[0068] Next, the wafer W to be processed is transferred to the bonding device 30 by the wafer transfer device 22. In the bonding device 30, as shown in FIG. 11(b), the wafer W to be processed and the support wafer S are bonded to form a polymerized wafer T.

[0069] Next, the polymerized wafer T is transferred to the peripheral removal device 210 by the wafer transfer device 22. In the peripheral removal device 210, as shown in FIG. 11(c), a part of the arc of the grinding wheel 212 is brought into contact with the outside of the modified layer M of the wafer W to be processed. In this state, while the grinding wheel 212 is lowered, the chuck 211 and the grinding wheel 212 are rotated respectively, and an impact is applied to the peripheral portion We of the wafer W to be processed. Due to this impact, as shown in FIG. 11(d), the peripheral portion We is peeled off and removed based on the modified layer M and the crack C.

[0070] Next, the polymerized wafer T is transported to the processing device 32 by the wafer transfer device 22. In the processing device 32, as shown in FIG. 11(e), the processing surface Wg of the wafer W to be processed is ground to the target thickness.

[0071] Thereafter, the polymerized wafer T that has undergone all the processes is transported to the cassette Ct on the cassette mounting table 10 by the wafer transfer device 22. Thus, a series of wafer processes in the substrate processing system 200 are completed.

[0072] Also in the above-described second embodiment, the same effects as those of the first embodiment can be obtained.

[0073] In the example shown in FIG. 11 in the second embodiment, the formation of the modified layer M, the bonding of the wafer W to be processed and the support wafer S, the removal of the peripheral portion We, and the grinding of the processing surface Wg of the wafer W to be processed were sequentially performed. However, the order of the formation of the modified layer M and the bonding of the wafer W to be processed and the support wafer S may be reversed. That is, the bonding of the wafer W to be processed and the support wafer S, the formation of the modified layer M, the removal of the peripheral portion We, and the grinding of the processing surface Wg of the wafer W to be processed may be performed in this order.

[0074] In the above embodiments, the case where one wafer W to be processed is bonded to the support wafer S has been described. However, wafers on which devices are formed may be bonded to each other, or a plurality of wafers W to be processed on which devices are formed may be stacked. In the following description, the case where a plurality of wafers W to be processed on which devices are formed are stacked using the substrate processing system 1 of the first embodiment will be described.

[0075] In the polymerized wafer T that has undergone the wafer process in the first embodiment, as shown in FIG. 12(a), the peripheral portion We of the wafer W to be processed is removed, and the processing surface Wg is ground to the target thickness. In the following description, this first wafer W to be processed is referred to as the first wafer W1 to be processed.

[0076] This polymerized wafer T is transported to the bonding device 30 by the wafer transfer device 22. Also, the wafer W to be processed, which is the third substrate to be laminated next, is also transported to the bonding device 30 by the wafer transfer device 22. In the following description, this second wafer W to be processed is referred to as the second wafer W2 to be processed. Then, in the bonding device 30, as shown in Fig. 12(a), the processed surface Wg of the first wafer W1 to be processed is bonded to the unprocessed surface Wn of the second wafer W2 to be processed, and the polymerized wafer T is formed.

[0077] Next, the polymerized wafer T is transported to the modification layer forming device 31 by the wafer transfer device 22. In the modification layer forming device 31, as shown in Fig. 12(b), a modification layer M is formed at a predetermined position inside the second wafer W2 to be processed.

[0078] Next, the polymerized wafer T is transported to the processing device 32 by the wafer transfer device 22. In the processing device 32, as shown in Fig. 12(c), while bringing a part of the arc of the second wafer W2 to be processed into contact with the grinding wheel 112 and lowering the grinding wheel 112, the chuck 111 and the grinding wheel 112 are rotated respectively to grind the processed surface Wg of the second wafer W2 to be processed. Then, as shown in Fig. 12(d), while the peripheral edge We is removed, the processed surface Wg of the second wafer W2 to be processed is ground to the target thickness.

[0079] After that, the polymerized wafer T that has undergone all the processes is transported to the cassette Ct on the cassette mounting table 10 by the wafer transfer device 22. Thus, a series of wafer processes in the substrate processing system 1 is completed.

[0080] Here, when removing the peripheral edge We of the second wafer W2 to be processed using a wheel as in the conventional method for the polymerized wafer T shown in Fig. 12(a), since the lower part of the unprocessed surface Wn of the second wafer W2 to be processed is hollow, it is difficult to grind the peripheral edge We. In contrast, in this embodiment, by forming the modification layer M inside the second wafer W2 to be processed, the peripheral edge We can be easily removed based on the modification layer M and the crack C.

[0081] Also, when using wheels or blades as in the prior art, there are limitations in the horizontal position adjustment of the wheels or blades, resulting in variations of about several micrometers. Then, variations also occur in the width (trim width) of the peripheral portion ground and removed by the wheels or blades, and especially when stacking the wafers to be processed, these variations are accumulated. For this reason, for example, the upper wafer to be processed may protrude from the lower wafer to be processed. On the other hand, in the present embodiment, since the modified layer M is formed inside the second wafer W2 to be processed by using a laser, high accuracy can be ensured and the wafers W to be processed can be appropriately stacked.

[0082] When stacking a plurality of wafers W to be processed as in the present embodiment, the peripheral portion We removed by the upper second wafer W2 to be processed may be inside the peripheral portion We removed by the lower first wafer W1 to be processed. That is, as shown in FIG. 13(a), the modified layer M inside the second wafer W2 to be processed may be formed radially inward from the end of the first wafer W1 to be processed. In such a case, as shown in FIG. 13(b), the diameter of the second wafer W2 finally stacked is smaller than the diameter of the first wafer W1 to be processed. Then, it is possible to surely prevent the second wafer W2 from protruding from the first wafer W1.

[0083] In the modified layer forming apparatus 31 of the above embodiment, as shown in FIG. 4, the modified layer M was formed at one location such that the lower end thereof was positioned above the target surface after grinding of the wafer W to be processed, but the method of forming the modified layer M is not limited to this.

[0084] As shown in FIGS. 14(a) to (d), a plurality of modified layers M may be formed in the thickness direction of the wafer W to be processed. In FIG. 14, a device layer and an oxide film formed at the interface between the wafer W to be processed and the support wafer S of the stacked wafer T are illustrated. That is, a device layer D in which a plurality of devices are formed is formed on the non-processed surface Wn of the wafer W to be processed, and an oxide film Fw (for example, SiO 2A film is formed. An oxide film Fs is also formed on the bonding surface Sj of the support wafer S. When a plurality of devices are formed on the bonding surface Sj of the support wafer S, a device layer (not shown) is formed on the bonding surface Sj in the same manner as the wafer W to be processed.

[0085] In the example shown in FIG. 14(a), the modification layers M1 to M4 are formed in a plurality of stages, for example, four stages, in the thickness direction of the wafer W to be processed. The lower end of the lowermost modification layer M4 is located above the target surface (dotted line in FIG. 14(a)) of the wafer W to be processed after grinding. Further, the cracks C that progress through these modification layers M1 to M4 reach the processed surface Wg and the unprocessed surface Wn of the wafer W to be processed.

[0086] In the example shown in FIG. 14(b), the modification layers M1 to M2 are formed in a plurality of stages, for example, two stages, in the thickness direction of the wafer W to be processed. The lower end of the lower modification layer M2 is located above the target surface (dotted line in FIG. 14(b)) of the wafer W to be processed after grinding. Further, the cracks C that progress through these modification layers M1 to M2 reach the unprocessed surface Wn of the wafer W to be processed, but do not reach the processed surface Wg. In such a case, for example, in the processing apparatus 32, when the grinding wheel 112 is lowered to grind the processed surface Wg, until the grinding surface of the grinding wheel 112 reaches the crack C, the processed surface Wg is ground including the peripheral edge We of the wafer W to be processed. Then, when the grinding surface of the grinding wheel 112 reaches the crack C, the peripheral edge We is peeled off and removed below the crack C. By controlling the height of the upper end of the crack C extending from the modification layers M1 to M2 to a predetermined position in this way, the size (height) of the small piece of the peripheral edge We to be removed can be controlled.

[0087] In the example shown in FIG. 14(c), the modified layers M1 to M4 are formed in a plurality of stages, for example, four stages, in the thickness direction of the wafer W to be processed. The lower end of the lowermost modified layer M4 is located below the target surface (dotted line in FIG. 14(c)) of the wafer W to be processed after grinding. Further, the crack C that progresses through these modified layers M1 to M4 has reached the processed surface Wg and the unprocessed surface Wn of the wafer W to be processed. In such a case, since the modified layer M4 is formed at the boundary between the peripheral portion We and the central portion Wc in the wafer W to be processed after grinding, the peripheral portion We can be more reliably peeled off and removed. When the modified layer M4 is formed below the target surface in this way, it is controlled by defocusing the laser beam so that the crack C extending from the modified layer M4 is less likely to occur. Then, generation of the crack C can be suppressed up to the support wafer S bonded to the wafer W to be processed. Although the position of the crack C changes in the circumferential direction, since the lower end of the modified layer M4 can be controlled in this way, it can be removed with high accuracy.

[0088] In the example shown in FIG. 14(d), the modified layers M1 to M4 are formed in a plurality of stages, for example, four stages, in the thickness direction of the wafer W to be processed. The lower end of the lowermost modified layer M4 is located inside the device layer D. Further, the crack C that progresses through these modified layers M1 to M4 has reached the processed surface Wg of the wafer W to be processed. Even in such a case, since the modified layer M4 is formed at the boundary between the peripheral portion We and the central portion Wc in the wafer W to be processed after grinding, the peripheral portion We can be more reliably peeled off and removed.

[0089] As shown in FIG. 14, the method of forming a plurality of modified layers M in the thickness direction of the wafer W to be processed is arbitrary, but for example, three processing methods are as shown in FIG. 15. FIG. 15 is a view in which the portion (the boundary between the peripheral portion We and the central portion Wc) where the modified layer M is formed in the wafer W to be processed is developed in a plane. That is, the horizontal direction in FIG. 15 indicates the circumferential direction of the boundary between the peripheral portion We and the central portion Wc, and the vertical direction indicates the thickness direction of the wafer W to be processed. Further, the dotted lines in FIG. 15 indicate the modified layers M1 to M4, and show a state in which a plurality of modified layers M1 to M4 are formed in the thickness direction of the wafer W to be processed.

[0090] In the processing method shown in Fig. 15(a), in the modification layer forming apparatus 31, while rotating the chuck 100 by the rotation mechanism 102, laser light is irradiated from the vertically fixed laser head 103 into the interior of the wafer W to be processed to form an annular modification layer M4. Next, after stopping the rotation of the chuck 100 and stopping the irradiation of the laser light from the laser head 103, the laser head 103 is raised by the elevating mechanism 105 to a predetermined position, that is, the position where the modification layer M3 is formed. Then, while rotating the chuck 100, laser light is irradiated from the laser head 103 to form an annular modification layer M3. The modification layers M2 and M1 are also formed in the same manner to form the modification layers M1 to M4 on the wafer W to be processed.

[0091] When forming the modification layers M1 to M4, the on / off control of the irradiation of the laser light from the laser head 103 may be performed while the rotation of the chuck 100 is continued. For example, while rotating the chuck 100, laser light is irradiated from the laser head 103 into the interior of the wafer W to be processed to form the modification layer M4. Then, while the rotation of the chuck 100 is continued, the irradiation of the laser light from the laser head 103 is once stopped. Subsequently, the laser head 103 is raised, and again laser light is irradiated from the laser head 103 into the interior of the wafer W to be processed to form the modification layer M3. At this time, by storing the irradiation start position and the irradiation end position of the laser light when forming the modification layer M4, the irradiation start position and the irradiation end position of the laser light when forming the modification layer M3 next can be made to coincide. And by not stopping the rotation of the chuck 100 as described above, the waiting time for the irradiation of the laser light during the acceleration and deceleration of the rotation of the chuck 100 can be shortened, and the overall processing time can be shortened. Furthermore, by maintaining the rotation speed of the chuck 100 at a constant speed, the laser processing can be performed uniformly, and it is also possible to make the horizontal pitch of the modification layer M equal.

[0092] In the processing method shown in Fig. 15(b), while rotating the chuck 100 by the rotation mechanism 102, laser light is irradiated from the vertically fixed laser head 103 into the interior of the wafer W to be processed to form an annular modified layer M4. Before the formation of this modified layer M4 is completed, with the rotation of the chuck 100 and the irradiation of laser light from the laser head 103 continued, the laser head 103 is raised by the lifting mechanism 105 to a predetermined position, that is, the position where the modified layer M3 is to be formed. Thereafter, with the vertical position of the laser head 103 fixed, while rotating the chuck 100, laser light is irradiated from the laser head 103 to form an annular modified layer M3. The modified layers M2 and M1 are also formed in the same manner, and the modified layers M1 to M4 are formed on the wafer W to be processed. In such a case, since the modified layers M1 to M4 can be formed continuously, the time required for the processing can be shortened compared to the processing method shown in Fig. 15(a).

[0093] In the processing method shown in Fig. 15(c), while rotating the chuck 100 by the rotation mechanism 102 and raising the laser head 103 by the lifting mechanism 105, laser light is irradiated from the laser head 103 into the interior of the wafer W to be processed to continuously form the annular modified layers M1 to M4. That is, in this processing method, the modified layers M1 to M4 are continuously formed in a spiral shape. Even in such a case, since the modified layers M1 to M4 can be formed continuously, the time required for the processing can be shortened compared to the processing method shown in Fig. 15(a). Moreover, the modified layers M1 to M4 are not formed with a steep gradient in a side view, and can be formed uniformly in the vertical direction (the thickness direction of the wafer W to be processed) compared to the processing method shown in Fig. 15(b).

[0094] In the above-described embodiment, in the reforming layer forming apparatus 31, an annular reforming layer M is formed inside the wafer W to be processed. However, as shown in FIG. 16, a plurality of radially extending reforming layers M' extending radially outward from the annular reforming layer M may be further formed. In such a case, for example, when removing the peripheral portion We by the processing apparatus 32, the peripheral portion We is divided into a plurality of parts by the radially extending reforming layers M' while peeling off from the annular reforming layer M as a base point. Then, the peripheral portion We to be removed becomes smaller and can be removed more easily.

[0095] Further, as a method of fragmenting the peripheral portion We (edge piece) to be removed during grinding of the processed surface Wg, as shown in FIG. 16, a plurality of annular divided reforming layers M'' may be formed at arbitrary intervals in the concentric direction with the reforming layer M. In such a case, the peripheral portion We to be removed can be made smaller. Further, by controlling the radial interval of the divided reforming layers M'', the size of the small pieces of the peripheral portion We to be removed can be controlled.

[0096] Furthermore, when forming such a plurality of annular divided reforming layers M'', as shown in FIG. 17, the divided reforming layers M'' may be formed in a spiral shape in a plan view. In such a case, in the reforming layer forming apparatus 31, while moving the chuck 100 or the laser head 103 in the horizontal direction and rotating the chuck 100, the laser head 103 irradiates the wafer W to be processed with laser light, so that the spiral divided reforming layers M'' can be continuously formed. As a result, the time required for the processing can be shortened.

[0097] Further, as shown in FIG. 18, the divided modification layer M” may be formed in a spiral shape and meandering in a plan view. In such a case, in the modification layer forming apparatus 31, while moving the chuck 100 or the laser head 103 in the horizontal direction, the chuck 100 is rotated and the laser head 103 irradiates the wafer W to be processed with laser light. At this time, by controlling the phase, period, and amplitude of the movement of the chuck 100 or the laser head 103, such a meandering wave-shaped divided modification layer M” can be formed. Further, the divided modification layer M” is formed for two or more turns. And by controlling the shift and frequency of the meandering phase of the divided modification layer M”, the size of the small pieces of the peripheral edge We to be removed can be controlled. In the present embodiment, the radial modification layer M’ shown in FIGS. 16 and 17 becomes unnecessary.

[0098] Also, as shown in FIG. 19(a), the divided modification layer M” may be formed such that the crack C extending from the divided modification layer M” extends to a predetermined position inside the wafer W to be processed. That is, the crack C reaches the non-processed surface Wn of the wafer W to be processed, but does not reach the processed surface Wg. In such a case, for example, when the grinding wheel 112 is lowered in the processing apparatus 32 to grind the processed surface Wg, until the grinding surface of the grinding wheel 112 reaches the crack C, the processed surface Wg is ground including the peripheral edge We of the wafer W to be processed as shown in FIG. 19(b). Then, when the grinding surface of the grinding wheel 112 reaches the crack C, the peripheral edge We peels off and is removed below the crack C. By controlling the upper end height of the crack C to a predetermined position in this way, the size (height) of the small pieces of the peripheral edge We to be removed can be controlled. In the example of FIG. 19, although the divided modification layer M” is formed in two stages, it is also possible to simultaneously form the two-stage divided modification layer M” while rotating the chuck 100 by adjusting the two condensing points from the laser head 103.

[0099] In the above embodiments, the following method may be used as a method for efficiently removing the peripheral portion We. That is, for example, before bonding the wafer W to be processed and the support wafer S in the bonding apparatus 30, by reducing the bonding force at the interface between the wafer W to be processed and the support wafer S in the portion corresponding to the peripheral portion We to be removed, the peripheral portion We can be efficiently removed. As a specific example of the method for reducing this bonding force, the following methods can be considered.

[0100] The first method for reducing the bonding force is, for example, a method of roughening the non-processed surface Wn of the wafer W to be processed in the portion corresponding to the peripheral portion We to be removed by irradiating it with a laser beam or the like. Specifically, the interface processing apparatus 300 shown in FIG. 20 is used. The interface processing apparatus 300 is provided at an arbitrary position in the processing station 3 of the substrate processing system 1, for example.

[0101] The interface processing apparatus 300 has a chuck 301 that holds the wafer W to be processed with the non-processed surface Wn facing upward. The chuck 301 is configured to be movable in the X-axis direction and the Y-axis direction by a moving mechanism 302. The moving mechanism 302 is composed of a general precision XY stage. Further, the chuck 301 is configured to be rotatable about the vertical axis by a rotation mechanism 303.

[0102] Above the chuck 301, a laser head 304 that irradiates the non-processed surface Wn at the peripheral portion We of the wafer W to be processed with a laser beam K is provided. The laser beam K irradiated from the laser head 304 is arbitrary, but for example, an excimer laser or a fiber laser is used. Although the device layer D and the oxide film Fw are formed on the non-processed surface Wn as described above, the laser beam may have a wavelength that is absorbed by the oxide film Fw, for example, 266 nm. The laser head 304 may be configured to be movable in the X-axis direction, the Y-axis direction, and the Z-axis direction by a moving mechanism (not shown).

[0103] The irradiation port of the laser beam K of the laser head 304 is configured to be movable horizontally by a moving mechanism (not shown). The moving mechanism may, for example, mechanically move the irradiation port of the laser head 304, or may move the irradiation port with an acoustic element. Since the laser beam is absorbed by the oxide film Fw, it is not necessary to strictly control its focusing point. Therefore, as in this embodiment, by the moving mechanism, the irradiation port of the laser head 304 can be moved to modify and roughen the non-processed surface Wn (oxide film Fw) at the peripheral edge We.

[0104] Above the chuck 301, a gas supply unit 305 for supplying gas to the wafer W to be processed is provided. As the gas supplied from the gas supply unit 305, for example, clean air or an inert gas such as nitrogen gas is used. The gas supply unit 305 has a nozzle 306 for supplying gas and a flow rectifying plate 307 for rectifying the gas supplied from the nozzle 306. The nozzle 306 communicates with a gas supply source (not shown) that stores and supplies gas. The gas supply port of the nozzle 306 is formed above the center of the wafer W to be processed. The flow rectifying plate 307 is provided substantially parallel to the wafer W to be processed held by the chuck 301, and controls the gas from the nozzle 306 to flow over the non-processed surface Wn of the wafer W to be processed.

[0105] Around the chuck 301, a cup 308 for collecting and exhausting the gas from the gas supply unit 305 is provided. An exhaust pipe 309 for exhausting the gas is connected to the lower surface of the cup 308. Note that the cup 308 may cover the entire circumference of the wafer W to be processed, or may locally cover only the periphery of the laser head 304.

[0106] In the interface processing apparatus 300, first, after holding the wafer W to be processed with the chuck 301, the chuck 301 is moved horizontally by the moving mechanism 302 to perform centering of the wafer W to be processed. Then, while rotating the chuck 301 by the rotation mechanism 303, the laser beam K is irradiated from the laser head 304 to the non-processed surface Wn at the peripheral edge We of the wafer W to be processed to roughen the non-processed surface Wn.

[0107] Also, when roughening the non-processed surface Wn, gas is supplied from the gas supply unit 305 to the non-processed surface Wn of the wafer W to be processed. The supplied gas flows over the entire surface of the non-processed surface Wn and is discharged from the exhaust pipe 309. When modifying the non-processed surface Wn in the peripheral portion We using laser light as in this embodiment, debris (dust) may be generated. If this debris adheres to the non-processed surface Wn in the central portion Wc, the device may be damaged. Therefore, by supplying and purging gas from the gas supply unit 305, it is possible to suppress the adhesion of debris to the non-processed surface Wn. Note that after the interface treatment in the interface treatment apparatus 300, the non-processed surface Wn may be further cleaned in another cleaning apparatus (not shown). In such a case, for example, compared with the case where there is no configuration for supplying gas between the flow rectifying plate 307 and the wafer W to be processed as in the interface treatment apparatus 300, in this embodiment, since the cleaning is performed by the interface treatment apparatus 300, the cleaning in the above-mentioned another cleaning apparatus can be moderately suppressed.

[0108] As shown in FIG. 21, at the position where the non-processed surface Wn is roughened, for example, the boundary between the non-processed surface Wn of the wafer W to be processed corresponding to the peripheral portion We to be removed and the non-processed surface Wn of the wafer W corresponding to the central portion Wc not to be removed may be modified to form a modified groove R1 as a joint force reduction portion for reducing the joint force. Further, a plurality of annular modified grooves R2 may be formed outside the modified groove R1. Alternatively, as shown in FIG. 22, the portion corresponding to the peripheral portion We may be modified in a planar shape to form a roughened modified surface R3. In such a case, the modified surface R3 may be formed by a plurality of modified grooves R2, or the modified surface R3 may be formed by adjusting the irradiation range of the laser light.

[0109] Next, the wafer processing performed using the substrate processing system 1 provided with the above-described interface treatment apparatus 300 will be described. In this embodiment, detailed description of the same processing as in the first embodiment will be omitted.

[0110] First, the wafer transfer device 22 takes out the wafer W to be processed in the cassette Cw and transfers it to the interface processing device 300. In the interface processing device 300, as shown in Fig. 23(a), the non-processed surface Wn (oxide film Fw) at the peripheral edge We of the wafer W to be processed is modified, and any one of the roughened modified grooves R1, R2, and modified surface R3 is formed.

[0111] Incidentally, in parallel with the roughening of the non-processed surface Wn in this interface processing device 300, the support wafer S in the cassette Cs is taken out by the wafer transfer device 22 and transferred to the bonding device 30.

[0112] Next, the wafer W to be processed is transferred to the bonding device 30 by the wafer transfer device 22. At this time, the front and back surfaces of the wafer W to be processed are inverted by the wafer transfer device 22 or an inversion device (not shown). In the bonding device 30, as shown in Fig. 23(b), the wafer W to be processed and the support wafer S are bonded to form a polymerized wafer T.

[0113] Next, the polymerized wafer T is transferred to the modification layer forming device 31 by the wafer transfer device 22. In the modification layer forming device 31, a modification layer M is formed at a predetermined position inside the wafer W to be processed as shown in Fig. 23(c). That is, the modification layer M is formed corresponding to the modification grooves R1, R2, and the modified surface R3.

[0114] Next, the polymerized wafer T is transferred to the processing device 32 by the wafer transfer device 22. In the processing device 32, as shown in Fig. 23(d), the processed surface Wg of the wafer W to be processed is ground to the target thickness. As the grinding of the processed surface Wg progresses, as shown in Fig. 23(e), the peripheral edge We of the wafer W to be processed is peeled off and removed based on the modification layer M and the crack C. At this time, since the interface (non-processed surface Wn) between the wafer W to be processed and the support wafer S is roughened and the bonding strength is reduced, the peripheral edge We can be appropriately removed.

[0115] After that, the polymerized wafer T subjected to all the processes is transferred to the cassette Ct on the cassette mounting table 10 by the wafer transfer device 22. Thus, a series of wafer processes in the substrate processing system 1 are completed.

[0116] In this embodiment, after forming any one of the modification grooves R1 and R2 and the modified surface R3 in the wafer W to be processed as shown in FIG. 23(a), the wafer W to be processed and the support wafer S are bonded as shown in FIG. 23(b), and further a modified layer M is formed in the wafer W to be processed as shown in FIG. 23(c). However, these orders are not limited. For example, the formation of the modification grooves R1 and R2, the modified surface R3, the formation of the modified layer M, and the bonding of the wafers W and S may be performed in this order. Further, for example, the formation of the modified layer M, the formation of the modification grooves R1 and R2, the modified surface R3, and the bonding of the wafers W and S may be performed in this order. Still further, for example, the formation of the modified layer M, the bonding of the wafers W and S, and the formation of the modification grooves R1 and R2, the modified surface R3 may be performed in this order.

[0117] Further, in this embodiment, the interface processing apparatus 300 is provided separately from the modified layer forming apparatus 31, but the interface processing apparatus 300 and the modified layer forming apparatus 31 may be the same apparatus. In such a case, for example, a laser head 304 is provided in the modified layer forming apparatus 31.

[0118] Alternatively, a protective film may be formed on the unprocessed surface Wn prior to the laser processing in the interface processing apparatus 300. In such a case, the processing station 3 of the substrate processing system 1 is provided with a coating apparatus (not shown) for forming the protective film and a cleaning apparatus (not shown) for cleaning the protective film. The coating apparatus forms the protective film by applying a protective material to the entire surface of the unprocessed surface Wn by, for example, the spin coating method. Further, the cleaning apparatus supplies a cleaning liquid to the entire surface of the unprocessed surface Wn by, for example, the spin cleaning method to clean and remove the protective film.

[0119] In the substrate processing system 1, first, in the coating apparatus, a protective film is formed on the entire non-processed surface Wn. Then, in the interface processing apparatus 300, as shown in FIG. 23(a), the non-processed surface Wn at the peripheral edge We is modified. At this time, since the protective film is formed on the central portion Wc of the wafer W to be processed, even if debris is generated by the laser light, it is possible to suppress the device from being damaged. Then, in the cleaning apparatus, if the protective film on the non-processed surface Wn is cleaned and removed, then, as shown in FIG. 23(b), the wafer W to be processed and the support wafer S can be bonded.

[0120] The second method for reducing the bonding force is, for example, a method of applying a release agent to the non-processed surface Wn of the wafer W to be processed corresponding to the portion to be removed, i.e., the peripheral edge We, to form a release film. Specifically, for example, the interface processing apparatus 310 shown in FIG. 24 is used. Note that the interface processing apparatus 310 is provided at an arbitrary position in the processing station 3 of the substrate processing system 1, for example.

[0121] The interface processing apparatus 310 has a chuck 311 that holds the wafer W to be processed with the non-processed surface Wn facing upward. The chuck 311 is configured to be rotatable about the vertical axis by a rotation mechanism 312.

[0122] Above the chuck 311, a nozzle 313 for applying the release agent A to the non-processed surface Wn at the peripheral edge We of the wafer W to be processed is provided. The nozzle 313 communicates with a release agent supply source (not shown) that stores and supplies the release agent A. Further, the nozzle 313 may be configured to be movable in the X-axis direction, Y-axis direction, and Z-axis direction by a moving mechanism (not shown). Any material that reduces the bonding force at the interface between the wafer W to be processed and the support wafer S may be used as the release agent A.

[0123] The wafer processing method performed using the substrate processing system 1 provided with the above-described interface processing apparatus 310 is a method in which, as shown in FIG. 23, the laser processing of the interface processing apparatus 300 is changed to the release agent coating process of the interface processing apparatus 310. In the interface processing apparatus 310, while rotating the chuck 311, the release agent A is applied from the nozzle 313 to the unprocessed surface Wn of the peripheral edge We, whereby a release film is formed on the unprocessed surface Wn. Then, since the bonding force between the wafer W to be processed and the support wafer S is reduced by the release film at the peripheral edge We, the peripheral edge We can be appropriately removed in FIG. 23(e).

[0124] Note that when the rotation speed of the chuck 311 in the interface processing apparatus 310 is high, the applied release agent A is thrown off to the outside of the wafer W to be processed by centrifugal force. On the other hand, when the rotation speed of the chuck 311 is medium, there is a possibility that the release agent A may enter the processed surface Wg of the wafer W to be processed. Therefore, a rinse liquid of the release agent A may be supplied from the processed surface Wg side. Further, when the rotation speed of the chuck 311 is low, the release agent A may be sucked and discharged from the outside of the wafer W to be processed.

[0125] The third method for reducing the bonding force is, for example, a method of thinly etching the unprocessed surface Wn of the wafer W to be processed corresponding to the portion corresponding to the peripheral edge We to be removed with a chemical solution or the like. For example, in the case of a TEOS film, etching is performed with hydrofluoric acid. The configuration of the interface processing apparatus for performing this etching is arbitrary, and a known etching apparatus can be used.

[0126] In the present embodiment, instead of the laser processing of the interface processing apparatus 300 shown in FIG. 23(a), the etching process of the peripheral edge We is performed. The etched peripheral edge We is removed to form a step with the central portion Wc, or the etched peripheral edge We is roughened. Then, when the wafer W to be processed and the support wafer S are bonded by the bonding apparatus 30 as shown in FIG. 23(b), the wafer W to be processed and the support wafer S are not bonded at the peripheral edge We. Therefore, the peripheral edge We can be appropriately removed in FIG. 23(e).

[0127] The fourth method for reducing the bonding force is, for example, when the bonding apparatus 30 is a plasma-utilizing bonding apparatus as described above, irradiating the non-processed surface Wn of the wafer W corresponding to the peripheral portion We to be removed with plasma during bonding. As described above, in the bonding apparatus 30, the non-processed surface Wn is irradiated with plasma ions such as oxygen ions or nitrogen ions, and the non-processed surface Wn is plasma-treated and activated. Therefore, in this bonding apparatus 30, a shielding plate may be provided above the non-processed surface Wn so that oxygen ions or nitrogen ions are not irradiated onto the non-processed surface Wn at the peripheral portion We.

[0128] In such a case, in the bonding apparatus 30, the non-processed surface Wn at the central portion Wc of the wafer W to be processed is activated by oxygen ions or nitrogen ions, but the non-processed surface Wn at the peripheral portion We is not activated. Then, when the wafer W to be processed and the support wafer S are bonded by the bonding apparatus 30 as shown in Fig. 23(b), the wafer W to be processed and the support wafer S are not bonded at the peripheral portion We. For this reason, the peripheral portion We can be appropriately removed in Fig. 23(e).

[0129] In the above embodiments, the above four processes are performed on the non-processed surface Wn of the wafer W to be processed before bonding to reduce the bonding force, but the same process may be performed on the bonding surface Sj of the support wafer S.

[0130] In the above embodiments, as a method for efficiently removing the peripheral portion We, after the wafer W to be processed and the support wafer S are bonded by the bonding apparatus 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 is reduced, whereby the peripheral portion We can be efficiently removed. As a specific example of this method for reducing the bonding force, the following methods can be considered.

[0131] For example, laser light is transmitted to the non-processed surface Wn of the wafer W to be processed, and ablation occurs at each interface. Specifically, for example, the processing apparatus 320 shown in FIG. 25 is used. Note that the processing apparatus 320 is provided, for example, in place of the modification layer forming apparatus 31 at the processing station 3 of the substrate processing system 1.

[0132] The processing apparatus 320 further includes a laser head 321, a moving mechanism 322, and a lifting mechanism 323 in the configuration of the modification layer forming apparatus 31. The laser head 321 irradiates the non-processed surface Wn with laser light for modification. The laser head 321 emits high-frequency pulsed laser light oscillated from a laser light oscillator (not shown), and condenses and irradiates laser light having a wavelength that is transmissive to the wafer W to be processed at a predetermined position inside the wafer W to be processed. As a result, the portion where the laser light is condensed inside the wafer W to be processed is modified. The moving mechanism 322 moves the laser head 321 in the X-axis direction and the Y-axis direction. The moving mechanism 322 is configured by a general precision XY stage. Further, the lifting mechanism 323 moves the laser head 321 in the Z-axis direction. As described above, the processing apparatus 320 functions as both a modification layer forming apparatus and an interface processing apparatus.

[0133] When processing the interface between the wafer W to be processed and the support wafer S with the processing apparatus 320, the inside of the wafer W to be processed or the inside of the device layer D is modified. That is, the interfaces in the present embodiment include the inside of the wafer W to be processed and the inside of the device layer D.

[0134] When modifying the inside of the wafer W to be processed as shown in Fig. 26, in the peripheral portion We (outside the modified layer M), a modified surface R4 is formed in the vicinity of the unprocessed surface Wn. As this processing method, as shown in Fig. 27, laser light L is irradiated from the laser head 321 toward the inside of the wafer W to be processed. The laser light L passes through the inside of the wafer W to be processed and is focused, and the focused portion is modified. Then, while rotating the chuck 100 by the rotation mechanism 102, the laser head 321 is moved radially outward by the movement mechanism 322, and the laser light L is irradiated from the laser head 321 toward the inside of the wafer W to be processed. Then, the modified surface R4 is formed. When forming the modified surface R4, the chuck 100 may be moved radially by the movement mechanism 101, or both the laser head 321 and the chuck 100 may be moved.

[0135] Note that when forming the modified surface R4 inside the wafer W to be processed in this way, after removing the peripheral portion We, a part of the wafer W to be processed remains on the support wafer S. Therefore, after removing the peripheral portion We, a part of the remaining wafer W to be processed may be etched and removed.

[0136] When modifying the inside of the device layer D as shown in Fig. 28, in the peripheral portion We (outside the modified layer M), a modified surface R5 is formed inside the device layer D. As this processing method, for example, there are three methods as shown in Fig. 29.

[0137] The first processing method is a method of positioning the focus point of the laser beam L from the laser head 321 above the device layer D inside the wafer W to be processed, as shown in Fig. 29(a). In such a case, the energy of the laser beam L is reduced so that the wafer W to be processed is not modified even when the laser beam L is focused. Then, the laser beam L is once focused inside the wafer W to be processed, but the further defocused and spread laser beam L passes through the wafer W to be processed and irradiates the device layer D. The laser beam L is absorbed by the device layer D, and ablation occurs in the device layer D. Then, while rotating the chuck 100 by the rotation mechanism 102, the laser head 321 is moved radially outward by the movement mechanism 322, and the laser beam L is irradiated from the laser head 321. Then, a modified surface R5 is formed on the device layer D. When forming the modified surface R5, the chuck 100 may be moved radially by the movement mechanism 101, or both the laser head 321 and the chuck 100 may be moved.

[0138] The second processing method is a method of positioning the focus point of the laser beam L from the laser head 321 inside the device layer D, as shown in Fig. 29(b). In such a case, the laser beam L passes through the wafer W to be processed and irradiates the device layer D, and ablation occurs in the device layer D. Then, while rotating the chuck 100 by the rotation mechanism 102, the laser head 321 is moved radially outward by the movement mechanism 322, and the laser beam L is irradiated from the laser head 321. Then, a modified surface R5 is formed on the device layer D. When forming the modified surface R5, the chuck 100 may be moved radially by the movement mechanism 101, or both the laser head 321 and the chuck 100 may be moved.

[0139] The third processing method is a method of positioning the focus point of the laser beam L from the laser head 321 below the device layer D as shown in FIG. 29(c). In such a case, the laser beam L passes through the wafer W to be processed and irradiates the device layer D, causing ablation of the device layer D. Since the laser beam L is absorbed by the device layer D, it does not focus below the device layer D. Then, while rotating the chuck 100 by the rotation mechanism 102, the laser beam L is irradiated from the laser head 321 while moving the laser head 321 radially outward by the moving mechanism 322. Then, a modified surface R5 is formed on the device layer D. When forming the modified surface R5, the chuck 100 may be moved radially by the moving mechanism 101, or both the laser head 321 and the chuck 100 may be moved.

[0140] Note that when forming the modified surface R5 on the device layer D, the ablation effect on the device layer D at the peripheral portion We may affect the device layer D at the central portion Wc inside it. Therefore, as shown in FIG. 14(d), it is preferable to form the modified layer M4 on the device layer D and then form the modified surface R5. In such a case, the modified layer M4 serves to block the influence of ablation, and it is possible to reliably prevent the influence of the ablation from reaching the central portion Wc.

[0141] Next, the wafer processing performed using the substrate processing system 1 provided with the above processing apparatus 320 will be described. In this embodiment, detailed descriptions of the same processes as those in the first embodiment are omitted.

[0142] First, the wafer W to be processed in the cassette Cw is taken out by the wafer transfer device 22 and transferred to the bonding device 30. Subsequently, the support wafer S in the cassette Cs is also taken out by the wafer transfer device 22 and transferred to the bonding device 30. In the bonding device 30, as shown in FIG. 30(a), the wafer W to be processed and the support wafer S are bonded to form a polymerized wafer T.

[0143] Next, the polymerized wafer T is transported to the processing device 320 by the wafer transfer device 22. In the processing device 320, the laser head 103 is moved above the peripheral edge We. Then, while rotating the chuck 100, laser light is irradiated from the laser head 103 into the interior of the wafer W to be processed, and a modified layer M is formed at a predetermined position inside the wafer W to be processed as shown in Fig. 30(b).

[0144] Subsequently, in the processing device 320, the laser head 103 is retracted, and the laser head 321 is moved above the peripheral edge We. Then, while rotating the chuck 100, the laser head 321 is moved radially outward while irradiating laser light from the laser head 321. As a result, a modified surface R4 or R5 is formed inside the wafer W to be processed or on the device layer D as shown in Fig. 30(c).

[0145] Note that the formation order of the modified layer M shown in Fig. 30(b) and the modified surface R4 or R5 shown in Fig. 30(c) may be reversed.

[0146] Next, the polymerized wafer T is transported to the processing device 32 by the wafer transfer device 22. In the processing device 32, as shown in Fig. 30(d), the processed surface Wg of the wafer W to be processed is ground to the target thickness. As the grinding of the processed surface Wg progresses, as shown in Fig. 30(e), the peripheral edge We of the wafer W to be processed is peeled off and removed based on the modified layer M and the crack C. At this time, since the modified surface R4 or R5 is formed at the interface between the wafer W to be processed and the support wafer S and the bonding force is reduced, the peripheral edge We can be appropriately removed.

[0147] Thereafter, the polymerized wafer T that has undergone all the processes is transported to the cassette Ct on the cassette mounting table 10 by the wafer transfer device 22. Thus, a series of wafer processes in the substrate processing system 1 is completed.

[0148] Also in this embodiment, the same effects as those of the first and second embodiments can be achieved. Moreover, in the processing device 320, since the same chuck 100 is used to form the modified layer M and the modified surfaces R4 or R5, the wafer W to be processed does not become eccentric during the processing by the laser head 103 and the processing by the laser head 321. As a result, the position of the modified layer M can be made to coincide with the inner peripheral position of the modified surface R4 or R5, and the peripheral portion We can be removed more appropriately.

[0149] Note that in the processing device 320, the laser head 103 and the laser head 321 do not necessarily need to be provided separately, and may be a common head. Also, the laser head 103 and the laser head 321 in the processing device 320 may be provided in different devices, and may be provided in the modified layer forming device 31 and the interface processing device, respectively.

[0150] Also, this embodiment can be applied even when a second wafer W2 to be processed is further laminated on the polymerized wafer T as shown in FIG. 12. At this time, when the position of the peripheral portion We removed by the second wafer W2 to be processed coincides with the position of the polymerized wafer T, the formation of the modified surface R4 or R5 can be omitted.

[0151] Also, this embodiment can be applied even when the peripheral portion We removed by the upper second wafer W2 to be processed is made inside the peripheral portion We removed by the lower first wafer W1 to be processed as shown in FIG. 13. However, in this case, in the second wafer W2 to be processed, it is preferable that the modified surface R4 or R5 is formed on the peripheral portion We removed from the first wafer W1 to be processed.

[0152] In the above embodiments, it is preferable that the position of the modified groove R1 formed in the wafer W to be processed before bonding, the inner peripheral position of the modified surface R3, or the inner peripheral positions of the modified surfaces R4 and R5 formed in the wafer W to be processed after bonding all coincide with the position of the modified layer M.

[0153] In explaining this reason, as an example, FIG. 31 shows a case where the wafer to be processed W is eccentrically bonded to the polymerized wafer T, and the position of the modified layer M and the inner peripheral position of the modified surface R4 are shifted. In such a case, as shown in FIG. 31, there are a place where the modified layer M is located radially inside the inner periphery of the modified surface R4 and a place where the modified layer M is located radially outside the inner periphery of the modified surface R4.

[0154] When the modified layer M is located radially inside the inner periphery of the modified surface R4 as shown in FIG. 32(a), when grinding the processed surface Wg of the wafer to be processed W to remove the peripheral portion We as shown in FIG. 32(b), the width D1 of the removed peripheral portion may be smaller than the target width D2 of the peripheral portion We to be removed. In addition, since the removed peripheral portion peels off without passing through the modified layer M and the crack C, the outer surface of the wafer to be processed W after removing the peripheral portion may become rough.

[0155] Note that even when the modified layer M is located radially inside the inner periphery of the modified surface R4, if the distance between the modified layer M and the inner periphery of the modified surface R4 is sufficiently small, the bonding force between the wafer to be processed W and the support wafer S becomes sufficiently small, so that the peripheral portion We can be removed.

[0156] When the modified layer M is located radially outside the inner periphery of the modified surface R4 as shown in FIG. 33(a), when grinding the processed surface Wg of the wafer to be processed W to remove the peripheral portion We as shown in FIG. 33(b), the modified surface R4 remains between the wafer to be processed W and the device layer D. In a portion where this modified surface R4 exists, the wafer to be processed W and the device layer D may peel off, and chipping may occur.

[0157] As methods for eliminating such a shift in the position of the modified layer M and the inner peripheral position of the modified surface R4, the following two methods can be considered. The first shift elimination method is a method of detecting the eccentricity of the wafer to be processed W in the polymerized wafer T and adjusting the position of the modified layer M or the inner peripheral position of the modified surface R4 based on the detection result. The second shift elimination method is a method of detecting the position of the modified layer M or the inner peripheral position of the modified surface R4 and adjusting the position of the modified surface R4 or the modified layer M formed in subsequent processing based on the detection result.

[0158] When executing the above two misalignment elimination methods, for example, the processing device 330 shown in FIG. 34 is used. The processing device 330 is provided, for example, instead of the processing device 320 at the processing station 3 of the substrate processing system 1. The processing device 330 has, in the configuration of the processing device 320, an eccentricity detection unit 331 for executing the first misalignment elimination method and a position detection unit 332 for executing the second misalignment elimination method.

[0159] The first misalignment elimination method will be described. The eccentricity detection unit 331 is disposed above the central portion of the chuck 100. Note that the eccentricity detection unit 331 is configured to be movable in the X-axis direction, Y-axis direction, and Z-axis direction by a moving mechanism (not shown). The eccentricity detection unit 331 has, for example, a CCD camera. Then, the eccentricity detection unit 331 images at least three points on the outer peripheral portion of the polymerization wafer T held by the chuck 100, specifically. Then, the deviation of the center of the wafer W to be processed with respect to the rotation center of the chuck 100, that is, the eccentricity of the wafer W to be processed in the polymerization wafer T is detected. Note that the configuration of the eccentricity detection unit 331 is not limited to this embodiment, and it may have, for example, an IR camera. In such a case, the eccentricity detection unit 331 images, for example, the alignment marks formed on the wafer W to be processed, and detects the eccentricity of the wafer W to be processed in the polymerization wafer T.

[0160] The first misalignment elimination method is performed using the detection result of the eccentricity detection unit 331. Here, the description will be made along the case where the wafer processing shown in FIG. 30 is performed in the substrate processing system 1.

[0161] First, in the bonding device 30, as shown in FIG. 30(a), the wafer W to be processed and the support wafer S are bonded to form the polymerization wafer T. Next, the polymerization wafer T is transferred to the processing device 330. In the processing device 330, after the polymerization wafer T is held by the chuck 100, the polymerization wafer T is imaged by the eccentricity detection unit 331, and the eccentricity of the wafer W to be processed in the polymerization wafer T is detected. The detection result of the eccentricity detection unit 331 is output to the control device 40.

[0162] In the control device 40, based on the detection result of the eccentricity detection unit 331, that is, the eccentricity 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 FIG. 30(b). Further, 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 FIG. 30(c).

[0163] As described above, based on the detection result of the eccentricity of the wafer W to be processed by the eccentricity detection unit 331, by adjusting the central axis of the chuck 100, the irradiation axis of the laser head 103, or the irradiation axis of the laser head 321, the position of the modified layer M and the inner peripheral position of the modified surface R4 can be made to coincide.

[0164] Note that the eccentricity detection unit 331 may be provided in an eccentricity detection device (not shown) outside the processing device 320. In such a case, when the polymerized wafer T is transported from the eccentricity detection device to the processing device 320 by the wafer transfer device 22, the polymerized wafer T is transported so that the center of the wafer W to be processed coincides with the center of the chuck 100 based on the detection result of the eccentricity of the wafer W to be processed by the eccentricity detection unit 331. Then, as shown in FIG. 30(b), a modified layer M can be appropriately formed on the wafer W to be processed, and as shown in FIG. 30(c), a modified surface R4 can be appropriately formed inside the wafer W to be processed or in the device layer. Therefore, the position of the modified layer M and the inner peripheral position of the modified surface R4 can be made to coincide.

[0165] Further, the eccentricity detection unit 331 may detect the eccentricity of the second wafer W2 to be further laminated and bonded to the polymerized wafer T. Even in such a case, based on the detection result of the eccentricity of the second wafer W2 with respect to the polymerized wafer T, the position of the modified layer M and the inner peripheral position of the modified surface R4 can be made to coincide.

[0166] A second method for eliminating misalignment will be described. The position detection unit 332 is disposed above the outer peripheral portion of the chuck 100. Note that the position detection unit 332 is configured to be movable in the X-axis direction, Y-axis direction, and Z-axis direction by a moving mechanism (not shown). For the position detection unit 332, an IR camera using, for example, infrared rays is used. Then, the position detection unit 332 detects the position of the modified layer M formed on the wafer W to be processed or the inner peripheral position of the modified surface R4 with respect to the polymerized wafer T held by the chuck 100.

[0167] The second misalignment elimination method is performed using the detection result of the position detection unit 332. Here, a description will be given along the case where wafer processing shown in FIG. 30 is performed in the substrate processing system 1.

[0168] First, in the bonding apparatus 30, as shown in FIG. 30(a), the wafer W to be processed and the support wafer S are bonded to form the polymerized wafer T. Next, the polymerized wafer T is transported to the processing apparatus 330. In the processing apparatus 330, a modified layer M is formed on the wafer W to be processed as shown in FIG. 30(b) using the laser head 103.

[0169] When the modified layer M is formed on the wafer W to be processed, the modified layer M inside the wafer W to be processed is imaged using infrared rays by the position detection unit 332, and the position of the modified layer M is detected. The detection result of the position detection unit 332 is output to the control device 40.

[0170] Based on the detection result of the position detection unit 332, that is, the position of the modified layer M, the control device 40 adjusts the central axis of the chuck 100 or the irradiation axis of the laser head 321. Then, as shown in FIG. 30(c), a modified surface R4 can be appropriately formed on the wafer W to be processed. As a result, the position of the modified layer M and the inner peripheral position of the modified surface R4 can be made to coincide.

[0171] Note that the order of forming the modified layer M shown in FIG. 30(b) and forming the modified surface R4 shown in FIG. 30(c) may be reversed. In such a case, after forming the modified surface R4 on the wafer W to be processed, the modified surface R4 is imaged using infrared rays by the position detection unit 332, and the inner peripheral position of the modified surface R4 is detected. The detection result of the position detection unit 332 is output to the control device 40.

[0172] Based on the detection result of the position detection unit 332, that is, the inner peripheral position of the modified surface R4, the control device 40 adjusts the central axis of the chuck 100 or the irradiation axis of the laser head 103. Then, 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 peripheral position of the modified surface R4.

[0173] Also, in the above embodiment, the position detection unit 332 detects the position of the modified layer M formed on the wafer W to be processed after bonding or the inner peripheral position of the modified surface R4, but it may also detect the position of the modified layer M formed on the wafer W to be processed before bonding or the inner peripheral position of the modified surface R4. Even in such a case, after the detection by the position detection unit 332, the modified surface R4 or the modified layer M can be appropriately formed to make the position of the modified layer M coincide with the inner peripheral position of the modified surface R4.

[0174] In short, regardless of whether the formation of the modified layer M or the formation of the modified surface R4 is performed first, by detecting the position of the modified layer M or the inner peripheral position of the modified surface R4 with the position detection unit 332, the modified surface R4 or the modified layer M can be appropriately formed thereafter, and the position of the modified layer M can be made to coincide with the inner peripheral position of the modified surface R4.

[0175] Next, a substrate processing system according to the third embodiment of the present invention will be described. FIG. 35 is a plan view schematically showing the outline of the configuration of a substrate processing system 400 according to the third embodiment.

[0176] The substrate processing system 400 has a configuration in which a loading / unloading station 401 where a cassette Ct capable of accommodating a plurality of polymerization wafers T can be loaded and unloaded to / from the outside, for example, and a processing station 402 equipped with various processing apparatuses for performing predetermined processing on the polymerization wafers T are integrally connected.

[0177] The loading / unloading station 401 is provided with a cassette mounting table 410. In the illustrated example, a plurality of, for example, four cassettes Ct can be mounted in a row in the Y-axis direction on the cassette mounting table 410. Note that the number of cassettes Ct mounted on the cassette mounting table 410 is not limited to the present embodiment and can be arbitrarily determined.

[0178] The loading / unloading station 401 is provided with a wafer transfer region 420 adjacent to the cassette mounting table 410. In the wafer transfer region 420, a wafer transfer device 422 that is movable on a transfer path 421 extending in the Y-axis direction is provided. The wafer transfer device 422 has, for example, two transfer arms 423, 423 that hold and transfer the polymerization wafer T. Each transfer arm 423 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. Note that the configuration of the transfer arm 423 is not limited to the present embodiment and can take any configuration.

[0179] The processing station 402 is provided with a wafer transfer region 430. In the wafer transfer region 430, a wafer transfer device 432 that is movable on a transfer path 431 extending in the X-axis direction is provided. The wafer transfer device 432 is configured to be able to transfer the polymerization wafer T to a transition device 434, wet etching devices 440, 441, and a processing device 450, which will be described later. The wafer transfer device 432 has, for example, two transfer arms 433, 433 that hold and transfer the polymerization wafer T. Each transfer arm 433 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. Note that the configuration of the transfer arm 433 is not limited to the present embodiment and can take any configuration.

[0180] Between the wafer transfer area 420 and the wafer transfer area 430, a transition device 434 for transferring the polymerized wafer T is provided.

[0181] On the positive Y-axis side of the wafer transfer area 430, wet etching devices 440 and 441 are arranged side by side in this order in the X-axis direction from the loading / unloading station 401 side. In the wet etching devices 440 and 441, wet etching is performed on the processed surface Wg of the wafer W to be processed with a chemical solution such as hydrofluoric acid.

[0182] On the positive X-axis side of the wafer transfer area 430, a processing device 450 is arranged. In the processing device 450, processing operations such as grinding and cleaning are performed on the wafer W to be processed. The processing device 450 includes a rotary table 460, a transfer unit 470, a processing unit 480, a first cleaning unit 490, a second cleaning unit 500, a rough grinding unit 510, a medium grinding unit 520, and a finish grinding unit 530.

[0183] The rotary table 460 is configured to be rotatable by a rotation mechanism (not shown). Four chucks 461 for adsorbing and holding the polymerized wafer T are provided on the rotary table 460. The chucks 461 are evenly arranged on the same circumference as the rotary table 460, that is, at intervals of 90 degrees. The four chucks 461 can be moved to the transfer position A0 and the processing positions A1 to A3 when the rotary table 460 rotates. In addition, each of the four chucks 461 is configured to be rotatable by a rotation mechanism (not shown) around the vertical axis.

[0184] In this embodiment, the delivery position A0 is located on the negative X-axis side and the negative Y-axis side of the rotary table 460. On the negative X-axis side of the delivery 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 and arranged in this order from above. The first processing position A1 is located on the positive X-axis side and the negative Y-axis side of the rotary table 460, where the rough grinding unit 510 is arranged. The second processing position A2 is located on the positive X-axis side and the positive Y-axis side of the rotary table 460, where the semi-finishing grinding unit 520 is arranged. The third processing position A3 is located on the negative X-axis side and the positive Y-axis side of the rotary table 460, where the finish grinding unit 530 is arranged.

[0185] The transfer unit 470 is an articulated robot having a plurality of, for example, three arms 471. Each of the three arms 471 is configured to be rotatable. A transfer pad 472 for adsorbing and holding the polymer wafer T is attached to the tip arm 471. Further, the base end arm 471 is attached to a moving mechanism 473 that moves the arm 471 in the vertical direction. And the transfer unit 470 having such a configuration can transfer the polymer wafer T to the delivery position A0, the processing unit 480, the first cleaning unit 490, and the second cleaning unit 500.

[0186] In the processing unit 480, the horizontal orientation of the polymer wafer T before the grinding process is adjusted. For example, while rotating the polymer wafer T held by the chuck 100, the position of the notch portion of the wafer W to be processed is detected by a detection unit (not shown), and the position of the notch portion is adjusted to adjust the horizontal orientation of the polymer wafer T.

[0187] Further, the processing unit 480 has the configuration of the processing apparatus 320, that is, the chuck 100, the moving mechanism 101, the rotating mechanism 102, the laser head 103, the moving mechanism 104, the elevating mechanism 105, the laser head 321, the moving mechanism 322, and the elevating mechanism 323. In the processing unit 480, a modified layer M is formed on the wafer W to be processed by the laser head 103, and a modified surface R4 or R5 is formed on the wafer W to be processed by the laser head 321. When the modified layer M is previously formed on the wafer W to be processed, only the modified surface R4 or R5 is formed in the processing unit 480. Conversely, when the modified surface R4 or R5 is previously formed on the wafer W to be processed, only the modified layer M is formed in the processing unit 480.

[0188] In the first cleaning unit 490, the processed surface Wg of the wafer W after the grinding process is cleaned, and more specifically, spin cleaning is performed. For example, while rotating the polymer wafer T held by a spin chuck (not shown), a cleaning liquid is supplied from a cleaning liquid nozzle (not shown) to the processed surface Wg. Then, the supplied cleaning liquid diffuses on the processed surface Wg, and the processed surface Wg is cleaned.

[0189] In the second cleaning unit 500, the non-bonding surface Sn of the support wafer S in a state where the wafer W to be processed after the grinding process is held by the transfer pad 472 is cleaned, and the transfer pad 472 is also cleaned.

[0190] In the rough grinding unit 510, the processed surface Wg of the wafer W to be processed is roughly ground. The rough grinding unit 510 has a rough grinding section 511. The rough grinding section 511 has the grinding wheel 112, the spindle 113, and the drive section 114 shown in FIG. 6. The rough grinding section 511 is configured to be movable in the vertical direction and the horizontal direction along the support column 512.

[0191] In the intermediate grinding unit 520, the processed surface Wg of the wafer W to be processed is intermediate ground. The intermediate grinding unit 520 has an intermediate grinding section 521. The intermediate grinding section 521 has the grinding wheel 112, the spindle 113, and the drive section 114 shown in FIG. 6. Further, the intermediate grinding section 521 is configured to be movable in the vertical direction and the horizontal direction along the support column 522. Note that the grain size of the abrasive grains of the grinding wheel 112 of the intermediate grinding section 521 is smaller than the grain size of the abrasive grains of the grinding wheel 112 of the rough grinding section 511.

[0192] In the finish grinding unit 530, the processed surface Wg of the wafer W to be processed is finish ground. The finish grinding unit 530 has a finish grinding section 531. The finish grinding section 531 has the grinding wheel 112, the spindle 113, and the drive section 114 shown in FIG. 6. Further, the finish grinding section 531 is configured to be movable in the vertical direction and the horizontal direction along the support column 532. Note that the grain size of the abrasive grains of the grinding wheel 112 of the finish grinding section 531 is smaller than the grain size of the abrasive grains of the grinding wheel 112 of the intermediate grinding section 521.

[0193] Next, the wafer processing performed using the substrate processing system 400 configured as described above will be described. In the present embodiment, the description will be made along the case of performing the wafer processing shown in FIG. 30.

[0194] First, a cassette Ct containing a plurality of polymer wafers T is placed on the cassette mounting table 410 of the loading / unloading station 401. Note that in the present embodiment, the wafer W to be processed and the support wafer S are bonded as shown in FIG. 30(a) in a bonding apparatus (not shown) outside the substrate processing system 400.

[0195] Next, the polymer wafer T in the cassette Ct is taken out by the wafer transfer device 422 and transferred to the transition device 434. Subsequently, the polymer wafer T of the transition device 434 is taken out by the wafer transfer device 432 and transferred to the processing device 450.

[0196] The polymerized wafer T conveyed to the processing apparatus 450 is delivered to the processing unit 480. In the processing unit 480, the horizontal orientation of the wafer W to be processed is adjusted by a detection unit (not shown). In the processing unit 480, further, after forming the modified layer M on the wafer W to be processed as shown in FIG. 30(b) using the laser head 103, the modified surface R4 or R5 is formed on the wafer W to be processed as shown in FIG. 30(c) using the laser head 321.

[0197] Next, the polymerized wafer T is conveyed by the transfer unit 470 from the processing unit 480 to the delivery position A0 and delivered to the chuck 461 at the delivery position A0. Thereafter, the chuck 461 is moved to the first processing position A1. Then, the processing surface Wg of the wafer W to be processed is roughly ground as shown in FIG. 30(d) by the rough grinding unit 510. Then, as shown in FIG. 30(e), the peripheral portion We of the wafer W to be processed is peeled off and removed based on the modified layer M and the crack C. At this time, since the modified surface R4 or R5 is formed at the interface between the wafer W to be processed and the support wafer S and the bonding force is reduced, the peripheral portion We can be appropriately removed.

[0198] 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 intermediate ground by the intermediate grinding unit 520. In the rough grinding unit 510 described above, when the peripheral portion We cannot be completely removed, the peripheral portion We is completely removed by this intermediate grinding unit 520. That is, the peripheral portion We may be removed in two steps of the rough grinding unit 510 and the intermediate grinding unit 520. In such a case, the size of the peripheral portion We to be removed can be gradually reduced. That is, the peripheral portion We removed by each grinding unit 510, 520 becomes smaller.

[0199] Next, the chuck 461 is moved to the third processing position A3. Then, the processing surface Wg of the wafer W to be processed is finish ground by the finish grinding unit 530.

[0200] Next, the chuck 461 is moved to the transfer position A0. Here, using a cleaning liquid nozzle (not shown), the processed surface Wg of the wafer W to be processed is roughly cleaned with the cleaning liquid. At this time, cleaning is performed to remove some of the dirt on the processed surface Wg.

[0201] Next, the polymer wafer T is conveyed from the transfer position A0 to the second cleaning unit 500 by the conveying unit 470. Then, in the second cleaning unit 500, with the wafer W to be processed held by the conveying pad 472, the non-bonding surface Sn of the support wafer S is cleaned and dried.

[0202] Next, the polymer wafer T is conveyed from the second cleaning unit 500 to the first cleaning unit 490 by the conveying unit 470. Then, in the first cleaning unit 490, using a cleaning liquid nozzle (not shown), the processed surface Wg of the wafer W to be processed is finish-cleaned with the cleaning liquid. At this time, the processed surface Wg is cleaned and dried to a desired cleanliness.

[0203] Next, the polymer wafer T is sequentially conveyed by the wafer conveying device 432 to the wet etching devices 440 and 441, and the processed surface Wg is wet-etched in two steps.

[0204] Thereafter, the polymer wafer T that has undergone all the processes is conveyed by the wafer conveying device 432 to the transition device 434, and further conveyed by the wafer conveying device 422 to the cassette Ct on the cassette mounting table 10. Thus, a series of wafer processes in the substrate processing system 400 are completed.

[0205] Also in the above-described third embodiment, the same effects as those of the first and second embodiments can be obtained.

[0206] Note that the substrate processing system 400 of this embodiment may further include a peripheral removal device 210. The peripheral removal device 210 is provided, for example, stacked on the processing unit 480 and the first cleaning unit 490.

[0207] In such a case, after the modified layer M and the modified surfaces R4 or R5 are formed in the processing unit 480, the peripheral portion We is removed with the modified layer M as a reference in the peripheral removal device 210. Thereafter, rough grinding in the rough grinding unit 510, intermediate grinding in the intermediate grinding unit 520, finish grinding in the finish grinding unit 530, cleaning of the non-bonding surface Sn in the second cleaning unit 500, cleaning of the processed surface Wg in the first cleaning unit 490, and wet etching of the processed surface Wg in the wet etching devices 440 and 441 are sequentially performed.

[0208] In this embodiment, the laser head 103 for forming the modified layer M and the laser head 321 for forming the modified surface R4 or R5 are each provided in the processing unit 480 that aligns the polymerized wafer T. However, the device configuration is not limited to this. A modified layer forming unit including the laser head 103, the moving mechanism 104, and the elevating mechanism 105 for forming the modified layer M and an interface processing unit including the laser head 321, the moving mechanism 322, and the elevating mechanism 323 for forming the modified surface R4 or R5 may be provided separately from the processing unit 480. The modified layer forming unit and the interface processing unit can be arranged at any position as long as the transfer unit 470 can transfer the polymerized wafer T. For example, the modified layer forming unit and the interface processing unit may be provided stacked on the processing unit 480. Alternatively, they may be provided at a position adjacent to the processing unit 480 in the horizontal direction, for example, on the side opposite to the processing unit 480 with the moving mechanism 473 interposed therebetween. Note that either one of the modified layer forming unit and the interface processing unit may be arranged inside the processing device 450. Alternatively, both the modified layer forming unit and the interface processing unit may be arranged outside the processing device 50.

[0209] In addition, the substrate processing system 400 of the present embodiment may be provided with a CMP apparatus (CMP: Chemical Mechanical Polishing) for polishing the processed surface Wg of the wafer W to be processed. In such a case, a cleaning apparatus for cleaning the processed surface Wg after polishing may be provided. The CMP apparatus may be provided, for example, on the negative Y-axis side of the wafer transfer region 430 in the processing station 402. Further, the cleaning apparatus may be provided, for example, on the positive X-axis side of the wafer transfer region 430, stacked on the wet etching apparatuses 440 and 441.

[0210] In the substrate processing system 400 of the present embodiment, the bonding of the wafer W to be processed and the support wafer S was performed by a bonding apparatus outside the substrate processing system 400. However, such a bonding apparatus may be provided inside the substrate processing system 400. In such a case, cassettes Cw, Cs, and Ct capable of accommodating a plurality of wafers W to be processed, a plurality of support wafers S, and a plurality of polymerized wafers T are carried in and out at the loading / unloading station 401 of the substrate processing system 400. And these cassettes Cw, Cs, and Ct can be placed in a row in the Y-axis direction on the cassette mounting table 410.

[0211] In the above embodiments, the case of directly bonding the wafer W to be processed and the support wafer S has been described. However, the wafer W to be processed and the support wafer S may be bonded via an adhesive.

[0212] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to such examples. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope of the technical idea described in the claims, and it is naturally understood that those also belong to the technical scope of the present invention.

Description of Reference Numerals

[0213] 1 Substrate processing system 2 Loading / unloading station 3 Processing station 22 Wafer transfer apparatus 30 Bonding apparatus 31 Modification layer forming device 32 Processing device 40 Control device 100 Chuck 101 Moving mechanism 102 Rotating mechanism 103 Laser head 104 Moving mechanism 105 Lifting mechanism 200 Substrate processing system 210 Peripheral removal device 300, 310 Interface processing device 320, 330 Processing device 400 Substrate processing system 401 Loading / unloading station 402 Processing station 450 Processing device 480 Processing unit 510 Rough grinding unit 520 Medium grinding unit 530 Finishing grinding unit C Crack D Device layer Fw, Fs Oxide film M Modification layer M' Radial modification layer M'' Divided modification layer R1, R2 Modification groove R3, R4, R5 Modification surface S Support wafer T Polymerization wafer W (W1, W2) Wafer to be processed Wc Central part We Peripheral part

Claims

1. A substrate processing method for processing a substrate, comprising: preparing a polymerized substrate in which a first substrate having a plurality of films formed on a non-processed surface and a second substrate are joined; performing a modified layer forming process for forming a modified layer inside the first substrate along a boundary between a peripheral portion and a central portion of the first substrate to be removed; performing a modification process on the inside of the first substrate near the non-processed surface of the first substrate in the peripheral portion and radially outward from the boundary; removing the peripheral portion with the modified layer as a reference point.

2. In the substrate processing method according to claim 1, the modification process is performed while rotating the polymerized substrate and moving a condensing portion of a laser beam radially inside the first substrate.

3. In the substrate processing method according to claim 2, the moving of the condensing portion of the laser beam radially is performed by moving a chuck that holds the polymerized substrate radially.

4. In the substrate processing method according to any one of claims 1 to 3, in the modified layer forming process, a radially modified layer extending radially outward from the boundary is formed inside the first substrate.

5. In the substrate processing method according to any one of claims 1 to 4, after removing the peripheral portion, a part of the first substrate remains on the second substrate.

6. A substrate processing system for processing a polymerized substrate in which a first substrate having a plurality of films formed on a non-processed surface and a second substrate are joined, comprising: forming a modified layer inside the first substrate along a boundary between a peripheral portion and a central portion of the first substrate to be removed; a processing device that performs a modification process on the inside of the first substrate near the non-processed surface of the first substrate in the peripheral portion and radially outward from the boundary; a peripheral removal device that removes the peripheral portion with the modified layer as a reference point; a transfer device that transfers the polymerized substrate between the processing device and the peripheral removal device.

7. In the substrate processing system according to claim 6, in the processing device, the formation of the modified layer inside the first substrate and the modification process inside the first substrate are performed by a common laser head.

8. In the substrate processing system according to claim 7, the processing device includes a chuck that holds the polymerized substrate, In the processing device, the modification process is performed while moving the condensing portion of the laser light irradiated from the laser head in the radial direction inside the first substrate by rotating the chuck and moving it in the radial direction.

Images