Delamination method and bonded wafer

Abstract

This suppresses device damage when forming a processed layer using a laser beam. [Solution] The second bonding film 22 of the second wafer 20 has a SiCN film 23, and a processed layer 31 is formed within the SiCN film 23 by irradiating the SiCN film 23 with a laser beam LB. Since the SiCN film 23 can absorb the laser beam LB well, the laser beam LB does not easily pass through the SiCN film 23. Therefore, without increasing the thickness of the SiCN film 23, it is possible to suppress the destruction of the second device 24 and the first device 13 located below the SiCN film 23 by irradiation with the laser beam LB.

Description

Technical Field

[0001] The present invention relates to a peeling method and a bonded wafer.

Background Art

[0002] In the technique disclosed in Patent Document 1, after bonding two wafers, one of the wafers is ground and removed, so that the devices of one wafer are transferred to the other wafer to manufacture a stacked wafer. In this grinding, about 10 μm of one wafer remains. Therefore, the thickness of the stacked wafer increases.

[0003] Also, as disclosed in Patent Document 2, there is a method of peeling one wafer by forming a processing layer on an insulating film disposed between two wafers with a laser beam having a wavelength that is permeable to one of the wafers.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique of Patent Document 2, in order not to damage the device, it is necessary to increase the film thickness of the insulating film, which reduces the productivity.

[0006] Therefore, an object of the present invention is to suppress damage to the device caused by the transmitted light that has passed through the insulating film when forming a processing layer with a laser beam in the insulating film disposed between the wafer and the device.

Means for Solving the Problems

[0007] The present invention provides a peeling method (this peeling method) for peeling a second wafer from a bonded wafer, which is formed by bonding the surfaces of a first wafer and a second wafer, on which a device is formed, via a first bonding film provided on the surface of the first wafer and a second bonding film provided on the surface of the second wafer, wherein the second wafer comprises a SiCN film as part of the second bonding film, and includes a laser processing step of forming a processed layer in the SiCN film by irradiating the bonded wafer from the second wafer side with a laser beam having a wavelength that is transparent to the second wafer, and a peeling step of peeling the second wafer from the bonded wafer at the processed layer.

[0008] In this delamination method, the second bonding film of the second wafer may include a device formed on the SiCN film.

[0009] In this delamination method, the second bonding film of the second wafer may include a metal film formed between the SiCN film and the device.

[0010] In this peeling method, the second bonding film of the second wafer may include an SiO2 film or a SiN film formed between the SiCN film and the metal film.

[0011] In this stripping method, the wavelength range of the laser beam is 1064 to 5000 nm, and the dose range of the laser beam is 0.1389 J / mm². 2 More than 0.7J / mm 2 The following is also acceptable.

[0012] The bonded wafer of the present invention (the bonded wafer) includes a first wafer having a device and a first bonding film formed on its surface, and a second wafer having a second bonding film formed on its surface, wherein the surfaces of the first wafer and the second wafer are bonded together via the first bonding film and the second bonding film, and the second bonding film includes a SiCN film formed on the surface of the second wafer and a device formed on the SiCN film.

[0013] In this bonded wafer, the second bonding film of the second wafer may include a metal film formed between the SiCN film and the device.

[0014] In this bonded wafer, the second bonding film of the second wafer may include a SiO2 film or a SiN film formed between the SiCN film and the metal film.

Advantages of the Invention

[0015] In this peeling method, the second bonding film disposed between the first wafer and the second wafer has a SiCN film. In the laser processing step, by irradiating the SiCN film with a laser beam from the second wafer side, a processed layer is formed in the SiCN film. Here, since the SiCN film can absorb the laser beam well, it is difficult for the laser beam to pass through the SiCN film. Therefore, without increasing the thickness of the SiCN film, it is possible to suppress the device, which is a fine wiring layer disposed below the SiCN film, from being damaged by the irradiation of the laser beam (escaping light) that has passed through the SiCN film 23.

Brief Description of the Drawings

[0016] [Figure 1] It is a cross-sectional view showing the preparation step. [Figure 2] It is a cross-sectional view showing the bonding step. [Figure 3] It is a cross-sectional view showing the laser processing step. [Figure 4] It is a cross-sectional view showing the peeling step. [Figure 5] It is a cross-sectional view showing another preparation step. [Figure 6] It is a cross-sectional view showing another bonding step. [Figure 7] It is a cross-sectional view showing another laser processing step. [Figure 8] It is a cross-sectional view showing another peeling step. [Figure 9] It is a cross-sectional view showing still another preparation step. [Figure 10] It is a cross-sectional view showing still another bonding step. [Figure 11] It is a cross-sectional view showing another laser processing step. [Figure 12] It is a cross-sectional view showing another peeling step. [Figure 13] It is a cross-sectional view showing another preparation step. [Figure 14] It is a cross-sectional view showing another bonding step. [Figure 15] It is a cross-sectional view showing a grinding step. [Figure 16] It is a cross-sectional view showing another laser processing step. [Figure 17] It is a cross-sectional view showing another peeling step.

Mode for Carrying Out the Invention

[0017] The wafer forming method according to the present embodiment includes a wafer manufacturing method for manufacturing a bonded wafer including a first wafer and a second wafer, and a peeling method for peeling the second wafer from the bonded wafer.

[0018] 〔Wafer Manufacturing Method; Preparation Step〕 First, the wafer manufacturing method will be described. In the wafer manufacturing method, first, a preparation step is performed. In this step, as shown in FIG. 1, a first wafer 10 and a second wafer 20 are prepared.

[0019] The first wafer 10 is a wafer made of, for example, silicon or glass. On the surface 11 of the first wafer 10, a plurality of first devices 13 and a first bonding film (SiO2 film) 14 covering the first devices 13 are formed.

[0020] The second wafer 20 is a wafer made of, for example, silicon. The second wafer 20 has a second bonding film 22 on its surface 21 and includes a SiCN film (second insulating film) 23 as a part of the second bonding film 22.

[0021] The second bonding film 22 has a SiCN film 23 formed over the entire surface 21 of the second wafer 20, a plurality of second devices 24 formed on the SiCN film 23, and a first insulating film (SiO2 film) 25 formed on the SiCN film 23 so as to cover the second devices 24. In the example shown in Figure 1, the second devices 24 are formed (stacked) on the surface of the SiCN film 23.

[0022] [Wafer manufacturing method; bonding process] After the preparation process, a bonding process is carried out. In this process, as shown in Figure 2, the surfaces of the first wafer 10, on which the first device 13 is formed on its surface 11, and the second wafer 20 are bonded together via a first bonding film 14 provided on the surface 11 of the first wafer 10 and a second bonding film 22 provided on the surface 21 of the second wafer 20. This forms a bonded wafer 30.

[0023] Specifically, as shown in Figure 2, the surface 21 side (the side on which the second bonding film 22 is located) of the second wafer 20 is bonded to the surface 11 of the first wafer 10, which is placed on the bonding table 3. In this process, for example, the first bonding film 14 on the first wafer 10 and the first insulating film 25 of the second bonding film 22 on the second wafer 20 are bonded together by plasma-activated bonding (surface-activated bonding), which is a direct bonding method. That is, the surfaces of the first bonding film 14 and the first insulating film 25 are activated by irradiation with a rare gas plasma, and by pressing these surfaces together, the first bonding film 14 and the first insulating film 25 are bonded (bonded) to each other. As a result, the first wafer 10 and the second wafer 20 are joined to each other via the first bonding film 14 and the second bonding film 22, thereby manufacturing a bonded wafer 30.

[0024] Thus, the bonded wafer 30 includes a first wafer 10 on which a first device 13 and a first bonding film 14 are formed on its surface 11, and a second wafer 20 on which a second bonding film 22 is formed on its surface 21. The surfaces of the first wafer 10 and the second wafer 20 are bonded together via the first bonding film 14 and the second bonding film 22. The second bonding film 22 includes a SiCN film 23 formed on the surface 21 of the second wafer 20, and a second device 24 formed on the SiCN film 23.

[0025] The joining table 3 described above may also be the chuck table 40 of the laser processing apparatus 4 shown below (see Figure 3).

[0026] [Removal method; laser processing process] Next, a method for delaminating the bonded wafer 30 will be described. This delamination method involves separating the second wafer 20 from the first wafer 10 (bonded wafer 30) while leaving the second device 24 of the second wafer 20 attached to the first wafer 10.

[0027] In the delamination method, a laser processing step is first performed. In this step, a laser beam with a wavelength that is transparent to the second wafer 20 is irradiated onto the bonded wafer 30 from the second wafer 20 side, thereby forming a processed layer within the SiCN film 23.

[0028] Specifically, first, an operator or a transport device (not shown) places the bonded wafer 30 on the holding surface 42 of the chuck table 40 of the laser processing apparatus 4, with the second wafer 20 facing upwards, as shown in Figure 3. Then, the control unit 45 of the laser processing apparatus 4 connects the holding surface 42 to a suction source (not shown), causing the first wafer 10 of the bonded wafer 30 to be held by suction on the holding surface 42 of the chuck table 40.

[0029] Next, as shown in Figure 3, the control unit 45 positions the laser irradiation unit 41, which is provided in the laser processing apparatus 4, above the chuck table 40.

[0030] In the laser processing apparatus 4, the chuck table 40 and the laser irradiation unit 41 are provided to be able to move relative to each other in the horizontal direction. In this embodiment, the chuck table 40 is movable in the X-axis direction and can rotate horizontally by a table movement mechanism 43. In addition, the laser irradiation unit 41 is movable in the Y-axis direction by a laser movement mechanism 44.

[0031] Furthermore, the laser irradiation unit 41 is configured to irradiate the second wafer 20 with a laser beam LB having a penetrating wavelength. Specifically, the wavelength of the laser beam LB is in the range of 1064 to 5000 nm, for example, 1342 nm. The dose range of the laser beam LB is, for example, 0.1389 J / mm². 2 More than 0.7J / mm 2 The following applies:

[0032] The control unit 45 then adjusts the positions of the laser irradiation unit 41 and the chuck table 40 using the table movement mechanism 43 and the laser movement mechanism 44, while confirming the relative position of the laser irradiation unit 41 and the bonded wafer 30 with the camera 46, thereby positioning the processing start position on the bonded wafer 30 directly below the laser irradiation unit 41. The control unit 45 also adjusts the focusing of the laser irradiation unit 41 so that the focal point of the laser beam LB emitted from the laser irradiation unit 41 is positioned within the SiCN film 23 of the second bonding film 22 of the second wafer 20 on the bonded wafer 30.

[0033] Next, the control unit 45 irradiates the bonded wafer 30 with a laser beam LB from the laser irradiation unit 41 and, as shown by arrow 301, moves the bonded wafer 30 along the X-axis direction with respect to the focal point of the laser beam LB by using the table moving mechanism 43 for processing and feeding. The speed of this movement is, for example, 120 mm / second. As a result, the SiCN film 23 is irradiated with the laser beam LB along the X-axis direction.

[0034] Subsequently, the control unit 45 changes the position of the laser irradiation unit 41 in the Y-axis direction using the laser movement mechanism 44, and irradiates the SiCN film 23 of the bonded wafer 30 with the laser beam LB along the X-axis direction. As a result, the laser beam LB is irradiated onto almost the entire surface of the SiCN film 23, and a processed layer (exfoliated layer) 31 is formed within the SiCN film 23. This processed layer 31 is a layer in which Si, C, and N are formed by the destruction of the parts of the SiCN film 23 that were irradiated with the laser beam LB. Alternatively, a processed layer 31 may be formed within the SiCN film 23 by irradiating the SiCN film 23 with a laser beam LB in a helical pattern.

[0035] [Peeling method; peeling process] After the laser processing step, a delamination step is performed. In this step, the second wafer 20 is separated from the bonded wafer 30 at the processing layer 31.

[0036] Specifically, as shown in Figure 4, the control unit 45 controls the moving mechanism 49 to position the suction table 47, which is provided in the laser processing apparatus 4, above the chuck table 40 and lower it, thereby bringing the holding surface 48 on the lower surface of the suction table 47 into contact with the second wafer 20, which is the upper surface of the bonded wafer 30 held by the chuck table 40.

[0037] Next, the control unit 45 connects the holding surface 48 to the suction source 200. As a result, the second wafer 20 is held by suction on the holding surface 48 of the suction table 47. Subsequently, the control unit 45 controls the moving mechanism 49 to raise the suction table 47 as shown by arrow 302. As a result, the second wafer 20 is separated from the bonded wafer 30 (first wafer 10) at the processing layer 31 formed on the SiCN film 23.

[0038] As a result, the second device 24 is transferred from the second wafer 20 to the first wafer 10, forming a first wafer 10 equipped with two types of devices (first device 13 and second device 24).

[0039] As described above, in this embodiment, the second bonding film 22 of the second wafer 20 has a SiCN film 23, and as shown in Figure 3, in the laser processing process, a laser beam LB is irradiated onto the SiCN film 23 to form a processed layer 31 within the SiCN film 23. Here, since the SiCN film 23 is capable of absorbing the laser beam LB well, the laser beam LB does not easily pass through the SiCN film 23. Therefore, without increasing the thickness of the SiCN film 23, it is possible to suppress the destruction of the second device 24 and the first device 13, which are fine wiring layers located below the SiCN film 23, by irradiation with laser beam LB (pass-through light) that has passed through the SiCN film 23. In other words, it is possible to suppress damage to the second device 24 and the first device 13 while avoiding a decrease in productivity due to increasing the thickness of the SiCN film 23.

[0040] Furthermore, in this embodiment, the wavelength of the laser beam LB used in the laser processing process is within the range of 1064 to 5000 nm. Laser beam LB having a wavelength in this range is easily transmitted through the second wafer 20 and absorbed by the SiCN film 23. Therefore, it is possible to further suppress the irradiation of the second device 24 by laser beam LB that passes through the SiCN film 23 without being absorbed (ejected light).

[0041] Furthermore, in this embodiment, the dose range of the laser beam LB is 0.1389 J / mm². 2 More than 0.7J / mm 2 The following is the case. In this regard, if the dose of the laser beam LB is large, damage may occur to the silicon second wafer 20, which is located above the target film, the SiCN film 23, due to the laser beam LB. If the second wafer 20 is damaged, its surface will need to be treated when the second wafer 20 is reused after being peeled off. Furthermore, if the damage to the second wafer 20 is too great, it may crack during the peeling process, making it difficult to peel off the second wafer 20.

[0042] Furthermore, if the dose of the laser beam LB is too small, it becomes difficult to form multiple interconnected streaky processing layers within the SiCN film 23 using the laser beam LB. This makes it difficult to form the processing layer 31 over the entire surface of the SiCN film 23, and thus difficult to peel off the second wafer 20.

[0043] Therefore, in this embodiment, the dose amount of the laser beam LB is 0.1389 J / mm². 2 ~0.7 J / mm 2 By setting the laser beam LB to this range, it is possible to form a processed layer 31 over the entire surface of the SiCN film 23 using the laser beam LB while suppressing damage to the second wafer 20 by the laser beam LB.

[0044] In the wafer forming method according to this embodiment, as shown in Figure 5, the second bonding film 22 of the second wafer 20 may further include a metal film 26 formed between the SiCN film 23 and the second device 24, in addition to the SiCN film 23, the second device 24, and the first insulating film 25 described above.

[0045] In other words, in this configuration, as shown in Figure 5, a first wafer 10 similar to that shown in Figure 1 and a second wafer 20 containing a metal film 26 are prepared in the preparation step of the wafer manufacturing method.

[0046] Subsequently, in the bonding process of the wafer manufacturing method, as shown in Figure 6, the surfaces of the first wafer 10 and the second wafer 20 are bonded together via a first bonding film 14 provided on the surface 11 of the first wafer 10 and a second bonding film 22 provided on the surface 21 of the second wafer 20. Specifically, as described above using Figure 3, the first bonding film 14 of the first wafer 10 and the first insulating film 25 of the second bonding film 22 of the second wafer 20 are bonded together, for example, by plasma-activated bonding. This results in the production of a bonded wafer 30 as shown in Figure 6.

[0047] In this configuration, the bonded wafer 30 includes a first wafer 10 on which a first bonding film 14 and a first device 13 are formed on its surface 11, and a second wafer 20 on which a second bonding film 22 is formed on its surface 21. The surfaces of the first wafer 10 and the second wafer 20 are bonded together via the first bonding film 14 and the second bonding film 22. The second bonding film 22 comprises a SiCN film 23 formed on the surface 21 of the second wafer 20, a second device 24 formed on the SiCN film 23, and a metal film 26 formed between the SiCN film 23 and the second device 24.

[0048] Furthermore, in the laser processing step for the delamination method of the bonded wafer 30, a laser beam LB having a wavelength that is transparent to the second wafer 20 is irradiated onto the bonded wafer 30 from the second wafer 20 side, similar to the laser processing step shown with reference to Figure 3, to form a processed layer 31 within the SiCN film 23. That is, as shown in Figure 7, the laser beam LB is irradiated onto almost the entire surface of the SiCN film 23 of the second wafer 20, and a processed layer 31 is formed within the SiCN film 23.

[0049] Subsequently, in the peeling step of the peeling method, the second wafer 20 is peeled from the bonded wafer 30 at the processed layer 31, similar to the peeling step shown in Figure 4. That is, as shown in Figure 8, the second wafer 20 is held by the suction table 47 of the laser processing apparatus 4, and by raising the suction table 47, the second wafer 20 is peeled from the bonded wafer 30 (first wafer 10) at the processed layer 31 formed on the SiCN film 23. This results in the formation of a first wafer 10 having two types of devices (first device 13 and second device 24) on its surface.

[0050] In this configuration, a metal film 26 is positioned below the SiCN film 23 during the laser processing step. This allows the laser beam LB that has passed through the SiCN film 23 to be reflected (shielded) by the metal film 26. Therefore, it is possible to suppress the irradiation of the second device 24 below the metal film 26 with the laser beam LB.

[0051] Furthermore, in the wafer forming method according to this embodiment, as shown in Figure 9, the second bonding film 22 of the second wafer 20 may further have a third insulating film 27 (SiO2 film or SiN film) formed between the SiCN film 23 and the metal film 26, in addition to the SiCN film 23, second device 24, first insulating film 25 and metal film 26 described above.

[0052] In other words, in this configuration, as shown in Figure 9, in the preparation step of the wafer manufacturing method, a first wafer 10 similar to that shown in Figure 1 and a second wafer 20 containing a metal film 26 and a third insulating film 27 are prepared.

[0053] Subsequently, in the bonding process of the wafer manufacturing method, as shown in Figure 10, the surfaces of the first wafer 10 and the second wafer 20 are bonded together via a first bonding film 14 provided on the surface 11 of the first wafer 10 and a second bonding film 22 provided on the surface 21 of the second wafer 20. Specifically, as described above using Figure 3, the first bonding film 14 of the first wafer 10 and the first insulating film 25 of the second bonding film 22 of the second wafer 20 are bonded together, for example, by plasma-activated bonding. This results in the production of a bonded wafer 30 as shown in Figure 10.

[0054] In this configuration, the bonded wafer 30 includes a first wafer 10 on which a first bonding film 14 and a first device 13 are formed on its surface 11, and a second wafer 20 on which a second bonding film 22 is formed on its surface 21. The surfaces of the first wafer 10 and the second wafer 20 are bonded together via the first bonding film 14 and the second bonding film 22. The second bonding film 22 comprises a SiCN film 23 formed on the surface 21 of the second wafer 20, a second device 24 formed on the SiCN film 23, a metal film 26 formed between the SiCN film 23 and the second device 24, and a third insulating film 27 (SiO2 film or SiN film) formed between the SiCN film 23 and the metal film 26.

[0055] Furthermore, in the laser processing step for the delamination method of the bonded wafer 30, a laser beam LB having a wavelength that is transparent to the second wafer 20 is irradiated onto the bonded wafer 30 from the second wafer 20 side, similar to the laser processing step shown with reference to Figure 3, to form a processed layer 31 within the SiCN film 23. That is, as shown in Figure 11, the laser beam LB is irradiated onto almost the entire surface of the SiCN film 23 of the second wafer 20, and a processed layer 31 is formed within the SiCN film 23.

[0056] Subsequently, in the peeling step of the peeling method, the second wafer 20 is peeled from the bonded wafer 30 at the processed layer 31, similar to the peeling step shown in Figure 4. That is, as shown in Figure 12, the second wafer 20 is held by suction using the suction table 47 of the laser processing apparatus 4, and by raising the suction table 47, the second wafer 20 is peeled from the bonded wafer 30 (first wafer 10) at the processed layer 31 formed on the SiCN film 23. This results in the formation of a first wafer 10 having two types of devices (first device 13 and second device 24) on its surface.

[0057] In this configuration, during the laser processing step, the third insulating film 27 and the metal film 26 are arranged in this order below the SiCN film 23. As a result, the third insulating film 27 isolates the SiCN film 23 and the metal film 26, thereby suppressing the transfer of heat generated in the SiCN film 23 by irradiation with the laser beam LB to the metal film 26.

[0058] Furthermore, in this configuration, the laser beam LB that has passed through the SiCN film 23 can also be shielded by the third insulating film 27. Therefore, damage to the metal film 26 due to irradiation with the laser beam LB can be suppressed, and irradiation of the second device 24 and the first device 13 with the laser beam LB can also be suppressed.

[0059] Furthermore, in the wafer formation method according to this embodiment, as shown in Figure 13, the second bonding film 22 of the second wafer 20 has the SiCN film 23 described above, but does not necessarily have the second device 24, the first insulating film 25, the metal film 26, and the third insulating film 27.

[0060] In other words, in this configuration, as shown in Figure 13, in the preparation step of the wafer manufacturing method, a first wafer 10 similar to that shown in Figure 1 and a second wafer 20 having a SiCN film 23 as the second bonding film 22 are prepared.

[0061] Subsequently, in the bonding process of the wafer manufacturing method, as shown in Figure 14, the surfaces of the first wafer 10 and the second wafer 20 are bonded together via a first bonding film 14 provided on the surface 11 of the first wafer 10 and a second bonding film 22 provided on the surface 21 of the second wafer 20. Specifically, as described above using Figure 3, for example, the SiCN films 23 of the first bonding film 14 on the first wafer 10 and the second bonding film 22 on the second wafer 20 are activated by irradiation with a rare gas plasma, and these surfaces are bonded together by plasma-activated bonding. As a result, a bonded wafer 30 as shown in Figure 14 is manufactured.

[0062] In this configuration, the bonded wafer 30 includes a first wafer 10 on which a first bonding film 14 and a first device 13 are formed on its surface 11, and a second wafer 20 on which a second bonding film 22 is formed on its surface 21. The surfaces of the first wafer 10 and the second wafer 20 are bonded together via the first bonding film 14 and the second bonding film 22, and the second bonding film 22 comprises a SiCN film 23 formed on the surface 21 of the second wafer 20.

[0063] Furthermore, in this configuration, the wafer manufacturing method of the wafer formation method includes the following grinding step (wafer backside grinding step) as a step performed after the bonding step.

[0064] [Wafer manufacturing method; grinding process] In this grinding process, the first wafer 10 of the bonded wafer 30 is ground to have a predetermined thickness. Specifically, first, an operator or a transport device (not shown) places the bonded wafer 30 on the holding surface 52 of the chuck table 50 of the grinding device 5 with the first wafer 10 facing upwards, as shown in Figure 15. Then, the control unit 55 of the grinding device 5 connects the holding surface 52 to a suction source (not shown), so that the second wafer 20 of the bonded wafer 30 is held by suction on the holding surface 52 of the chuck table 50.

[0065] Next, the control unit 55 positions the grinding mechanism 60 provided in the grinding device 5 above the chuck table 50. The grinding mechanism 60 includes a spindle 61, a spindle motor 62 for rotating the spindle 61, a grinding wheel 63 connected to the lower end of the spindle 61, and a lifting mechanism 66 for raising and lowering the spindle 61. The grinding wheel 63 includes an annular wheel base 64 and a plurality of grinding wheels 65 provided on the lower surface of the wheel base 64.

[0066] The control unit 55 then rotates the chuck table 50 holding the bonded wafer 30 using the rotation mechanism 51, and rotates the spindle 61 and grinding wheel 63 using the spindle motor 62. Furthermore, the control unit 55 lowers the spindle 61 using the lifting mechanism 66, bringing the grinding wheel 65 of the rotating grinding wheel 63 into contact with the first wafer 10 on the upper surface of the bonded wafer 30, and grinds the first wafer 10 to a predetermined thickness.

[0067] Following this grinding process, the laser processing step of the peeling method described above is performed. In this laser processing step, similar to the laser processing step shown with reference to Figure 3, a laser beam LB having a wavelength that is transparent to the second wafer 20 is irradiated onto the bonded wafer 30 from the second wafer 20 side to form a processed layer 31 within the SiCN film 23.

[0068] Specifically, as shown in Figure 16, a sheet-like support tape 33 is attached to the first wafer 10 of the bonded wafer 30 and the back surface of the ring frame 32, which has a larger diameter than the bonded wafer 30, by an operator or a processing device (not shown). This forms a work set 35 including the bonded wafer 30.

[0069] Next, the worker or a transport device (not shown) places the work set 35 on the holding surface 42 of the chuck table 40 of the laser processing device 4, with the second wafer 20 of the bonded wafer 30 facing upwards. Subsequently, as explained using Figure 3, the laser beam LB is irradiated onto almost the entire surface of the SiCN film 23 on the second wafer 20, and a processed layer 31 is formed within the SiCN film 23.

[0070] Next, in the peeling step of the peeling method, the second wafer 20 is peeled from the bonded wafer 30 at the processing layer 31, similar to the peeling step shown with reference to Figure 4. That is, as shown in Figure 17, the second wafer 20 is held by suction using the suction table 47 of the laser processing apparatus 4, and by raising the suction table 47, the second wafer 20 is peeled from the bonded wafer 30 (first wafer 10) at the processing layer 31 formed on the SiCN film 23. This results in the formation of a first wafer 10 having a predetermined thickness and equipped with the first device 13.

[0071] In this configuration, during the laser processing step, a processed layer 31 is formed within the SiCN film 23 by irradiating it with a laser beam LB. As described above, since the laser beam LB has difficulty passing through the SiCN film 23, it is possible to suppress the destruction of the first device 13 located below the SiCN film 23 by irradiation with the laser beam LB. [Explanation of Symbols]

[0072] 3: Table, 4: Laser processing machine, 5: Grinding machine, 10: First wafer, 11: Surface, 13: First device, 14: First bonding film, 20: Second wafer, 21: Surface, 22: Second bonding film, 23: SiCN film, 24: Second device, 25: First insulating film, 26: Metal film, 27: Third insulating film, 30: Bonded wafer, 31: Processed layer, 32: Ring frame, 33: Support tape, 35: Workset, 40: Chuck table, 41: Laser irradiation unit, 42: Holding surface, 43: Table movement mechanism, 44: Laser movement mechanism, 45: Control unit, 46: Camera, 47: Suction table, 48: Holding surface, 49: Moving mechanism, 50: Chuck table, 51: Rotation mechanism, 52: Holding surface, 55: Control unit, 60: Grinding mechanism, 61: Spindle, 62: Spindle motor, 63: Grinding wheel 64: Wheel base, 65: Grinding wheel, 66: Lifting mechanism, 200: Suction source, LB: Laser beam

Claims

1. A peeling method for peeling a second wafer from a bonded wafer, which is formed by bonding the surfaces of a first wafer and a second wafer, each having a device formed on its surface, via a first bonding film provided on the surface of the first wafer and a second bonding film provided on the surface of the second wafer, wherein the second wafer is peeled off the second wafer. The second wafer comprises a SiCN film as part of the second bonding film, A laser processing step in which a laser beam having a wavelength that is transparent to the second wafer is irradiated onto the bonded wafer from the second wafer side to form a processed layer in the SiCN film, A peeling step in which the second wafer is peeled off from the bonded wafer at the boundary of the processed layer, A peeling method, including

2. The second bonding film of the second wafer comprises a device formed on the SiCN film. The peeling method according to claim 1.

3. The second bonding film of the second wafer comprises a metal film formed between the SiCN film and the device. The peeling method according to claim 1.

4. The second bonding film of the second wafer is formed between the SiCN film and the metal film. ２ A film or SiN film is provided. The peeling method according to claim 3.

5. The wavelength range of the laser beam is 1064 to 5000 nm, and the dose range of the laser beam is 0.1389 J / mm². ２ 0.7J / mm or more ２ The following is: The peeling method according to claim 1.

6. A first wafer having a device and a first bonding film formed on its surface, The invention includes a second wafer on which a second bonding film is formed on its surface, The surfaces of the first wafer and the second wafer are joined together via the first bonding film and the second bonding film. The second bonding film includes a SiCN film formed on the surface of the second wafer, and a device formed on the SiCN film. Bonded wafer.

7. The second bonding film of the second wafer comprises a metal film formed between the SiCN film and the device. The bonded wafer according to claim 6.

8. The second bonding film of the second wafer is formed between the SiCN film and the metal film. ２ A film or SiN film is provided. The bonded wafer according to claim 7.

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