Processing methods
The method fixes SiC wafers to a transparent plate, uses laser thinning and cutting, and transfers them to minimize damage, enabling precise division and assembly into devices.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- DISCO CORP
- Filing Date
- 2024-11-21
- Publication Date
- 2026-06-02
AI Technical Summary
SiC wafers face damage risks during grinding and cutting due to their hardness, leading to chipping and cracking, especially when thinning to 100 μm or less, and adhering to tapes causes further issues.
A processing method involving fixing the SiC wafer surface to a transparent plate via a transparent material, thinning with laser processing, cutting with a cutting blade, and imaging through the transparent components to minimize damage, followed by transfer and stacking steps.
The method effectively suppresses damage to SiC wafers during processing, ensuring precise division and assembly into devices without tape adhesion.
Smart Images
Figure 2026089935000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a processing method.
Background Art
[0002] For example, a wafer made of SiC has a high load during grinding due to its hardness. When grinding with the surface protected by a tape made of resin, the tape is deformed by the pressing force during grinding, and chipping and cracking are likely to occur. Therefore, it is widely practiced to grind in a state fixed on a hard plate instead of using a tape.
[0003] On the other hand, when SiC is cut with a cutting blade from the Si surface where the device is formed on the surface toward the C surface on the back side, large chipping and cracking occur. Therefore, the surface side is adhered to a tape, and for example, a cutting device (see, for example, Patent Document 1 and Patent Document 2) is used to hold and cut the Si surface side on the surface with a holding table.
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, when the wafer is ground and thinned to, for example, 100 μm or less, there is a risk of damage when peeling from the hard plate and adhering the surface side to a tape. Improvement is eagerly desired for the damage before processing the wafer into devices.
[0006] An object of the present invention is to provide a processing method capable of suppressing damage to a wafer before processing.
Means for Solving the Problems
[0007] To solve the above-mentioned problems and achieve the objective, the processing method of the present invention is characterized by comprising: a fixing step of fixing the surface side of a wafer on which a plurality of devices are formed on its surface to a transparent plate via a transparent fixing material; a thinning step of thinning the wafer fixed to the transparent plate to a predetermined thickness; a holding step of holding the transparent plate with a holding table having at least a transparent portion after performing the thinning step; a processing step of processing the wafer held by the holding table; and an imaging step of imaging the surface side through the transparent portion of the holding table, the fixing material, and the transparent plate at least one of the following: before, after, or during the processing step.
[0008] The above processing method may include a processing step in which the wafer is divided into the plurality of devices, and a transfer step in which, after the processing step, a support member is attached to the back surface of the wafer divided into the plurality of devices, and the transparent plate is removed from the wafer divided into the plurality of devices.
[0009] In the above processing method, the wafer has a substrate and a device layer formed on the surface of the substrate, and the device is formed in each region partitioned by a plurality of intersecting division lines, and in the processing step, the substrate may be cut with a cutting blade along the division lines to form cutting grooves, and then the device layer may be divided by irradiating a laser beam along the cutting grooves.
[0010] The above processing method includes a transfer step in which, after the processing step, a support member is fixed to the back surface of the wafer divided into the plurality of devices and the transparent plate is removed from the wafer divided into the plurality of devices; a stacking step in which, after the transfer step, the surface sides of the devices are stacked on a second wafer; and a filling step in which, after the stacking step, a filler is filled from the back side of the devices, at least between the devices, wherein in the processing step, the cutting groove and the laser processing groove are formed such that the width of the laser processing groove that divides the device layer is narrower than the width of the cutting groove, thereby forming a stepped portion on the side of the device where the surface side of the device is larger than the back side. [Effects of the Invention]
[0011] This invention has the effect of suppressing damage to wafers before processing. [Brief explanation of the drawing]
[0012] [Figure 1] Figure 1 is a schematic perspective view showing the wafer to be processed in the processing method according to Embodiment 1. [Figure 2] Figure 2 is a flowchart showing the flow of the processing method according to Embodiment 1. [Figure 3] Figure 3 is a schematic cross-sectional view showing the wafer after the fixing step of the processing method shown in Figure 2. [Figure 4] Figure 4 is a schematic diagram showing the configuration of a laser beam irradiation unit that irradiates a wafer with a laser beam during the thinning step of the processing method shown in Figure 2. [Figure 5] Figure 5 is a schematic cross-sectional view showing the delamination layer formed inside the wafer during the thinning step of the processing method shown in Figure 2. [Figure 6] Figure 6 is a schematic side view showing a partial cross-section of the wafer separation process during the thinning step of the processing method shown in Figure 2. [Figure 7] Figure 7 is a schematic side view showing a partial cross-section of the cleaning step of the processing method shown in Figure 2. [Figure 8] FIG. 8 is a perspective view schematically showing a cutting device for imaging a wafer in an imaging step of the processing method shown in FIG. 2. [Figure 9] FIG. 9 is a side cross-sectional view schematically showing a state in which a wafer is being imaged in an imaging step of the processing method shown in FIG. 2. [Figure 10] FIG. 10 is a side cross-sectional view schematically showing a state in which a wafer is being cut in a processing step of the processing method shown in FIG. 2. [Figure 11] FIG. 11 is a side cross-sectional view schematically showing a state in which a wafer is being imaged during cutting in a processing step of the processing method shown in FIG. 2. [Figure 12] FIG. 12 is a cross-sectional view schematically showing a state in which a wafer is being laser processed during a processing step of the processing method shown in FIG. 2. [Figure 13] FIG. 13 is a cross-sectional view schematically showing a device after a processing step of the processing method shown in FIG. 2. [Figure 14] FIG. 14 is a cross-sectional view schematically showing a transfer step of the processing method shown in FIG. 2. [Figure 15] FIG. 15 is a cross-sectional view schematically showing a device after a stacking step of the processing method shown in FIG. 2. [Figure 16] FIG. 16 is a cross-sectional view schematically showing a device after a filling step of the processing method shown in FIG. 2. [Figure 17] FIG. 17 is a cross-sectional view schematically showing a planarization step of the processing method shown in FIG. 2. [Figure 18] FIG. 18 is a cross-sectional view schematically showing a thinning step of a processing method according to a modification of Embodiment 1 in a partial cross-section.
BEST MODE FOR CARRYING OUT THE INVENTION
[0013] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. In addition, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.
[0014] [Embodiment 1] The processing method according to Embodiment 1 of the present invention will be described based on the drawings. Figure 1 is a schematic perspective view showing the wafer to be processed in the processing method according to Embodiment 1. Figure 2 is a flowchart showing the flow of the processing method according to Embodiment 1.
[0015] (wafer) The processing method according to Embodiment 1 is a method for processing the wafer 1 shown in Figure 1. In Embodiment 1, the wafer 1 to be processed is a disc-shaped semiconductor wafer having a substrate 2 made of SiC and a device layer 3 formed on the surface of the substrate 2. As shown in Figure 1, the wafer 1 has a plurality of intersecting division lines 5 set on its surface 4, and a device 6 is formed in each region partitioned by the division lines 5. The device 6 is, for example, an integrated circuit such as an IC (Integrated Circuit) or an LSI (Large Scale Integration), or a memory (semiconductor memory device).
[0016] The processing method according to Embodiment 1, as shown in Figure 2, comprises a fixing step 1001, a thinning step 1002, a washing step 1003, a holding step 1004, an imaging step 1005, a processing step 1006, a transfer step 1007, a stacking step 1008, a filling step 1009, and a planarization step 1010.
[0017] (Fixed step) Figure 3 is a schematic cross-sectional view showing the wafer after the fixing step of the processing method shown in Figure 2. The fixing step 1001 is a step in which the surface 4 side of the wafer 1, on which a plurality of devices 6 are formed, is fixed to the transparent plate 20 via a transparent fixing material 21. In Embodiment 1, in the fixing step 1001, as shown in Figure 3, the surface 4 side of the wafer 1 is fixed to the thick, disc-shaped transparent plate 20 via a transparent fixing material 21.
[0018] The fixing material 21 is made of a material that is not translucent, such as an adhesive, wax, or double-sided tape that is transparent to visible light and does not contain pigments.
[0019] The transparent plate 20 is formed in a disc shape with the same diameter as the wafer 1 but thicker than the wafer 1, and is made of, for example, glass. The transparent plate 20 has a fixing material 21 laminated over its entire surface 4, fixing the surface 4 side of the wafer 1. For this reason, in Embodiment 1, the entire surface 4 of the wafer 1 is fixed to the transparent plate 20 via the fixing material 21.
[0020] (Thinning step) Figure 4 is a schematic diagram showing the configuration of a laser beam irradiation unit that irradiates a wafer with a laser beam in the thinning step of the processing method shown in Figure 2. Figure 5 is a schematic cross-sectional view showing the delamination layer formed inside the wafer in the thinning step of the processing method shown in Figure 2. Figure 6 is a schematic side view showing a partial cross-section of the wafer separation state in the thinning step of the processing method shown in Figure 2.
[0021] The thinning step 1002 is a step in which the wafer 1 fixed to the transparent plate 20 is thinned to a predetermined thickness. In Embodiment 1, in the thinning step 1002, the laser processing apparatus 30 shown in Figure 4 irradiates the back surface 7 side of the wafer 1 fixed to the transparent plate 20 with a laser beam 32 from the laser beam irradiation unit 31 to form a delamination layer 324, which is a separation starting point, inside the wafer 1.
[0022] As shown in Figure 4, the laser beam irradiation unit 25 includes a laser oscillator 33 that emits a laser beam 32, an attenuator 34, a spatial light modulator 35, a mirror 36, and an irradiation head 37.
[0023] The laser oscillator 33 has, for example, Nd:YAG as the laser medium and emits a pulsed laser beam 32 with a wavelength that penetrates SiC (for example, 1064 nm). The attenuator 34 adjusts the laser beam 32 emitted by the laser oscillator 33 and supplies it to the spatial light modulator 35.
[0024] The spatial light modulator 35 branches the laser beam 32. In Embodiment 1, for example, the spatial light modulator 35 branches the laser beam 32 so that the laser beam 32 emitted from the irradiation head 37 (described later) forms a plurality (for example, five) of focal points 321 that are arranged at equal intervals along the Y-axis.
[0025] The mirror 36 reflects the laser beam 32, which has been branched by the spatial light modulator 35, toward the irradiation head 37. The irradiation head 37 houses a focusing lens (not shown) and the like for focusing the laser beam 32. The irradiation head 37 emits the laser beam 32, which has been focused by the focusing lens, toward the holding surface side of the holding table that holds the wafer 1.
[0026] In Embodiment 1, in the thinning step 1002, the laser processing apparatus 30 holds the transparent plate 20 on the holding surface of the holding table, sets the focusing point 321 to a predetermined depth corresponding to the thickness of the wafer 1 to be thinned from the back surface 7, and irradiates the wafer 1 with the laser beam 32 while moving the holding table and the irradiation head 37 relative to each other in the X-axis direction.
[0027] The laser beam 32 is then branched, and each of its multiple focal points 321 is positioned inside the wafer 1 for irradiation. As shown in Figure 5, a modified region 322 in which the SiC crystal structure is disordered is formed inside the wafer 1, centered around each of the multiple focal points 321. In other words, with a single irradiation of the laser beam 32 moving in the X-axis direction relative to the wafer 1, multiple modified regions 322 aligned along the Y-axis are formed.
[0028] At this time, cracks 323 extend from each of the multiple modified regions 322 along a predetermined crystal plane, and the cracks 323 connect adjacent modified regions 322. As a result, a delamination layer 324 is formed inside the wafer 1, which includes the multiple modified regions 322 and the cracks 323 that propagate from each of the multiple modified regions 322.
[0029] In Embodiment 1, in the thinning step 1002, when the laser processing apparatus 30 forms a delamination layer 324 inside the wafer 1 along its entire length in the X-axis direction, the irradiation of the laser beam 32 is stopped and the wafer 1 and the irradiation head 37 are moved a predetermined distance in the Y-axis direction (hereinafter referred to as index feeding). In Embodiment 1, in the thinning step 1002, the operation of the laser processing apparatus 30 irradiating the entire length of the wafer 1 along the X-axis direction with the laser beam 32 and index feeding are repeated until a delamination layer 324 is formed over the entire surface of the wafer 1 at a predetermined depth from the back surface 7.
[0030] In Embodiment 1, in the thinning step 1002, as shown in Figure 6, the peeling device 40 holds the transparent plate 20 on the holding surface 42 of the support base 41. In Embodiment 1, in the thinning step 1002, as shown in Figure 6, the peeling device 40 supplies pure water 43 from a nozzle 45 to the back surface 7 side of the wafer 1, and applies ultrasonic waves to the back surface 7 of the wafer 1 via the pure water 43 from an ultrasonic vibration unit 44, thereby separating the back surface 7 side of the wafer 1 starting from the peeling layer 324 and thinning the wafer 1 fixed to the transparent plate 20.
[0031] (Washing step) Figure 7 is a schematic side view showing a partial cross-section of the cleaning step of the processing method shown in Figure 2. The cleaning step 1003 is a step of cleaning the wafer 1 after the thinning step 1002. In Embodiment 1, in the cleaning step 1003, the cleaning apparatus 50 supports the outer edge of the transparent plate 20 with a plurality of support rollers 51, and rotates the support rollers 51 to rotate the wafer 1 around its axis.
[0032] In Embodiment 1, in cleaning step 1003, the cleaning device 50 supplies cleaning solution 53 (pure water in Embodiment 1) from the cleaning nozzle 52 to the back surface 7 of the wafer 1 and the surface 4 of the transparent plate 20, as shown in Figure 7. In this invention, in cleaning step 1003, the wafer 1 and the transparent plate 20 may be cleaned simultaneously or sequentially.
[0033] (Imaging step) Figure 8 is a schematic perspective view showing a cutting apparatus that images a wafer in the imaging step of the processing method shown in Figure 2. Figure 9 is a schematic side cross-sectional view showing the state of imaging a wafer in the imaging step of the processing method shown in Figure 2. The imaging step 1005 is a step in which the surface 4 side is imaged through the transparent portion 62 of the holding table 61, the fixing material 21 and the transparent plate 20, at least one of the following: before, after, or during the processing step 1006.
[0034] In Embodiment 1, during the imaging step 1005, the cutting apparatus 60 shown in Figures 8 and 9 holds the transparent plate 20 by suction on the surface of the transparent portion 62 of the holding table 61, which is made of glass or the like. In Embodiment 1, during the imaging step 1005, as shown in Figure 9, the cutting apparatus 60 uses an imaging unit 63 to image the surface 4 side of the wafer 1 through the transparent portion 62 of the holding table 61, the fixing material 21, and the transparent plate 20. In Embodiment 1, during the imaging step 1005, the cutting apparatus 60 detects the planned division line 5 and performs alignment to align the planned division line 5 with the cutting edge 65 of the cutting blade 64 (shown in Figure 10).
[0035] (Processing step) Figure 10 is a schematic side cross-sectional view showing the wafer being cut during the processing step of the processing method shown in Figure 2. Figure 11 is a schematic side cross-sectional view showing the wafer being imaged during the cutting process in the processing step of the processing method shown in Figure 2. Figure 12 is a schematic cross-sectional view showing the wafer being laser-processed during the processing step of the processing method shown in Figure 2. Figure 13 is a schematic cross-sectional view showing the device after the processing step of the processing method shown in Figure 2.
[0036] The processing step 1006 is a step in which the wafer 1 held by the holding table 61 is processed. In Embodiment 1, in processing step 1006, as shown in Figure 10, the cutting device 60 moves the cutting edge 65 of the cutting blade 64 and the wafer 1 relative to each other along the planned division line 5, and cuts the cutting edge 65 of the cutting blade 64 from the back surface 7 side of the wafer 1 to the center in the thickness direction, thereby forming a cutting groove 10 in the wafer 1. In Embodiment 1, during processing step 1006, at a predetermined timing, as shown in Figure 11, the cutting device 60 images the surface 4 side through the transparent part 62 of the holding table 61, the fixing material 21 and the transparent plate 20, and performs a well-known kerf check.
[0037] In Embodiment 1, in processing step 1006, once cutting grooves 10 are formed on the back surface 7 along all planned division lines 5, as shown in Figure 12, the laser processing apparatus 70 holds a transparent plate 20 on the holding surface of a holding table (not shown), sets a focusing point 72 from the laser beam irradiation unit 71 to the bottom surface of the cutting grooves 10, and irradiates the wafer 1 with a laser beam 73 of an absorbing wavelength while relatively moving the laser beam irradiation unit 71 and the wafer 1 along the planned division lines 5. In Embodiment 1, in processing step 1006, the laser processing apparatus 70 ablates the bottom of the cutting grooves 10 to divide the wafer 1 into multiple devices 6 (shown in Figure 13).
[0038] Thus, in Embodiment 1, in processing step 1006, the base material 2 is cut with a cutting blade 64 along the planned division line 5 to form a cutting groove 10, and then a laser beam 73 is irradiated along the cutting groove 10 to divide the device layer 3. In Embodiment 1, in processing step 1006, the cutting groove 10 and the laser processing groove are formed such that the width of the laser processing groove that divides the device layer 3 is narrower than the width of the cutting groove 10, so that a stepped portion 9 is formed on the side surface 4 side of the device 6, which is larger than the back surface 7 side, as shown in Figure 13.
[0039] (Transfer step) Figure 14 is a schematic cross-sectional view showing the transfer step of the processing method shown in Figure 2. Note that the stepped portion 9 is omitted in Figure 14. The transfer step 1007 is a step in which, after the processing step 1006, a tape 22, which is a support member, is attached (fixed) to the back surface 7 of the wafer 1 which has been divided into multiple devices 6, and the transparent plate 20 is removed from the wafer 1 which has been divided into multiple devices 6. In Embodiment 1, in the transfer step 1007, as shown in Figure 14, an annular frame 23 is attached to the outer edge, the back surface 7 of the wafer 1 is attached to the center of a disc-shaped tape 22 which has a larger diameter than the wafer 1, and the transparent plate 20 is peeled off from the front surface 4 side of the wafer 1.
[0040] If bumps are formed on the surface side of device 6, an insulating film for bump sealing called NCF (Non-Conductive Film) may be attached to the surface of device 6, and the NCF may be broken along device 6 by expanding the tape to form a device 6 with NCF.
[0041] (Lamination step) Figure 15 is a schematic cross-sectional view showing the device after the lamination step of the processing method shown in Figure 2. Note that the stepped portion 9 is omitted in Figure 15. The lamination step 1008 is a step in which, after performing the transfer step 1007, multiple layers of the surface 4 side of the device 6 are laminated onto the second wafer 1-2. Note that the second wafer-2 has substantially the same configuration as wafer 1, so the same parts as wafer 1 are described by adding "-2" to the end of the reference numeral of wafer 1.
[0042] In Embodiment 1, in the stacking step 1008, as shown in Figure 15, the surface 4 side of device 6 is stacked on each device 6-2 of the second wafer 1-2. In the case of device 6 with NCF, device 6 is stacked on the second wafer 1-2 together with the NCF.
[0043] (Filling step) Figure 16 is a schematic cross-sectional view showing the device after the filling step of the processing method shown in Figure 2. Note that the stepped portion 9 is omitted in Figure 16. The filling step 1009 is a step in which, after performing the lamination step 1008, a filler material is filled between the devices 6 from the back surface 7 side of the devices 6. In Embodiment 1, in the filling step 1009, as shown in Figure 16, an oxide film 24 as a filler material is formed on the surface 4 of the second wafer 1-2, and the oxide film 24, which is the filler material, is filled between the separated devices 6.
[0044] (Flattening step) Figure 17 is a schematic cross-sectional view showing the planarization step of the processing method shown in Figure 2. Note that the stepped portion 9 is omitted in Figure 17. The planarization step 1010 is a step in which the surface of the filler material is flattened after the filling step 1009. In Embodiment 1, in the planarization step 1010, as shown in Figure 17, the grinding device 80 holds the back surface 7-2 side of the second wafer 1-2 by suction to the holding surface 82 of the holding table 81.
[0045] In Embodiment 1, in the planarization step 1010, the grinding device 80, as shown in Figure 17, rotates the grinding wheel 83 around its axis with the spindle 85 and rotates the holding table 81 around its axis while supplying grinding water, and brings the grinding wheel 84 into contact with the oxide film 24, which is the filler, and brings it closer to the holding table 81 at a predetermined feed rate, thereby grinding the surface of the oxide film 24 with the grinding wheel 84 and planarizing the surface of the oxide film 24.
[0046] After planarizing the oxide film 24, which is the filler, other devices are stacked on top of it, and finally the second wafer 1-2 is fragmented to form a stacked device.
[0047] The processing method according to Embodiment 1 described above involves thinning the wafer 1 while it is fixed to the transparent plate 20 via a transparent fixing material 21, and then processing the wafer 1 on the transparent plate 20 in processing step 1006 without reattaching it to tape.
[0048] As a result, the processing method according to Embodiment 1 has the effect of suppressing damage to the wafer 1 before processing to be divided into devices 6.
[0049] [Variation] A processing method relating to a modified example of Embodiment 1 will be described based on the drawings. Figure 18 is a schematic cross-sectional view showing a thinning step of the processing method relating to a modified example of Embodiment 1 in a partial cross-section. Note that in Figure 18, the same reference numerals are used for the same parts as in Embodiment 1, and their description is omitted.
[0050] The processing method according to a modified example of Embodiment 1 is the same as Embodiment 1, comprising a fixing step 1001, a thinning step 1002, a washing step 1003, a holding step 1004, an imaging step 1005, a processing step 1006, a transfer step 1007, a stacking step 1008, a filling step 1009, and a planarization step 1010, except that the thinning step 1002 is different.
[0051] In a modified example of Embodiment 1, in the thinning step 1002, as shown in Figure 18, the grinding device 80 holds the transparent plate 20 side by suction to the holding surface 82 of the holding table 81. In a modified example of Embodiment 1, in the thinning step 1002, as shown in Figure 18, the grinding device 80 rotates the grinding wheel 83 around its axis using the spindle 85 and rotates the holding table 81 around its axis while supplying grinding water, and brings the grinding wheel 84 into contact with the back surface 7 of the wafer 1 and brings it closer to the holding table 81 at a predetermined feed rate, thereby grinding the back surface 7 of the wafer 1 with the grinding wheel 84 and thinning the wafer 1.
[0052] In the modified version of Embodiment 1, the wafer 1 is thinned while fixed to the transparent plate 20 via a transparent fixing material 21, and then processed on the transparent plate 20 in processing step 1006 without reattaching it to tape. This method has the effect of suppressing damage to the wafer 1 during processing, similar to Embodiment 1.
[0053] It should be noted that the present invention is not limited to the embodiments described above. That is, it can be implemented with various modifications without departing from the core of the present invention. In addition, in the present invention, the imaging step 1005 may be performed after the cutting process in the processing step 1006. Furthermore, in the present invention, in addition to irradiating the wafer 1 with the laser beam 73 after the cutting process in the processing step 1006, the wafer 1 may be divided into individual devices 6 by cutting, the wafer 1 may be divided into individual devices 6 by irradiating it with the laser beam 73, or a modified layer may be formed on the wafer 1 by irradiating it with a laser beam of a wavelength that is transparent to the wafer 1. [Explanation of Symbols]
[0054] 1 wafer 1-2 Second wafer 2 Base material 3-device layer 4 surface Planned division lines (5 divisions) 6 devices 7 Back side 10 Cutting groove 20 transparent plates 21 Fixing material 22 Tape (support member) 24. Oxide film (filler) 61 Holding Table 62 Transparent part 73 Laser beams 1001 Fixed step 1002 Thinning step 1004 Holding step 1005 Imaging step 1006 Machining Steps 1007 Transfer Step 1008 Lamination Step 1009 Filling step
Claims
1. A fixing step involves fixing the surface side of a wafer on which multiple devices are formed to a transparent plate via a transparent fixing material, A thinning step in which the wafer fixed to the transparent plate is thinned to a predetermined thickness, After performing the thinning step, the holding step involves holding the transparent plate on a holding table having at least a portion of the transparent area, A processing step of processing the wafer held in the holding table, A processing method comprising: an imaging step of imaging the surface side of the holding table through the transparent portion, the fixing material, and the transparent plate at least either before, after, or during the processing step.
2. In this processing step, the wafer is divided into the multiple devices, The processing method according to claim 1, further comprising a transfer step of attaching a support member to the back surface of the wafer divided into the plurality of devices after the processing step, and removing the transparent plate from the wafer divided into the plurality of devices.
3. The wafer has a substrate and a device layer formed on the surface of the substrate, and the device is formed in each region partitioned by a plurality of intersecting division lines. The processing method according to claim 1, wherein in the processing step, the substrate is cut with a cutting blade along the planned division line to form a cutting groove, and then a laser beam is irradiated along the cutting groove to divide the device layer.
4. After the processing step, a transfer step is performed in which a support member is fixed to the back surface of the wafer which has been divided into multiple devices, and the transparent plate is removed from the wafer which has been divided into multiple devices. After performing the transfer step, a lamination step is performed in which multiple layers of the surface side of the device are stacked on a second wafer, The process includes a filling step, in which, after performing the lamination step, a filler material is filled at least between the devices from the back side of the devices, The processing method according to claim 3, wherein in the processing step, the cutting groove and the laser processing groove are formed such that the width of the laser processing groove that divides the device layer is narrower than the width of the cutting groove, thereby forming a stepped portion on the side surface of the device where the surface side is larger than the back side.