Wafer processing method

Abstract

To provide a wafer processing method that does not generate residual wafer portions that become a source of contamination when chamfering the outer periphery of a wafer.SOLUTION: A method includes a wafer holding step of holding a wafer W on a chuck table 7, a chamfering portion removal step of positioning a cutting blade 83A on an outer peripheral excess area 10B of the wafer W held on the chuck table 7 and rotating the chuck table 7 while rotating the cutting blade 83A to remove the chamfered portion, and a mirror polishing step of positioning a polishing blade instead of the cutting blade 83A on the outer periphery of the wafer W held on the chuck table 7 and from which the chamfered portion 10C has been removed, and rotating the chuck table 7 while rotating the polishing blade to polish the cutting surface 10d from which the chamfered portion 10C has been removed into a mirror surface.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a wafer processing method. [Background technology]

[0002] A wafer has a plurality of devices such as ICs and LSIs formed on its surface, separated by planned dividing lines. The back surface is ground by a grinding machine to form the wafer to the desired thickness, and then the wafer is divided into individual device chips by a dicing machine, which are then used in electrical devices such as mobile phones and personal computers.

[0003] Furthermore, a chamfer is formed on the outer periphery of the wafer, and when the back surface of the wafer is ground to thin it, the chamfer becomes as sharp as a knife edge, which can injure an operator or cause cracks to form from the outer periphery of the wafer to the inside, damaging the device.

[0004] The above-mentioned problem is not limited to a single wafer, but can also occur in a bonded wafer formed by bonding two wafers together. The bonded wafer is formed by bonding together wafers on which patterns are formed by, for example, a surface activation method.

[0005] In order to address the above-mentioned problems, the present applicant has proposed a technology in which, before grinding the back surface of the wafer, a laser beam having a wavelength that is transparent to the wafer is irradiated from a focal point positioned inside the chamfer, thereby forming a ring-shaped modified layer inside the wafer and removing the chamfer (see Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-88187 Summary of the Invention [Problem to be solved by the invention]

[0007] However, as described above, when the chamfered portion is removed starting from the modified layer, a small amount of the chamfered portion may not be completely removed from the outer periphery of the wafer, and this may cause problems such as the remaining portion falling off in a later process and becoming a source of contamination, or causing chipping of the device chips when the wafer is divided into individual device chips.

[0008] The present invention has been made in view of the above-mentioned circumstances, and its main technical object is to provide a wafer processing method that solves problems such as a situation in which a small amount of the chamfered portion remains on the outer periphery of a wafer without being completely removed, and this remaining portion falls off in a subsequent process to become a source of contamination, or causes chipping of device chips when the wafer is divided into individual device chips. [Means for solving the problem]

[0009] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a method for processing a wafer having an effective area including a device area in which a plurality of devices are partitioned by planned division lines, and an outer peripheral excess area in which a chamfered portion is formed surrounding the effective area, the method comprising the steps of: preparing a processing device including a chuck table for holding the wafer; cutting means having a rotatable cutting blade for cutting the chamfered portion of the wafer held on the chuck table; and polishing means having a rotatable polishing blade for polishing the surface from which the chamfered portion has been removed; A wafer processing method is provided which includes: a wafer holding step for holding the wafer on a chuck table; a chamfer removing step for positioning the cutting blade on the peripheral excess area of ​​the wafer held on the chuck table and rotating the chuck table while rotating the cutting blade to remove the chamfer; and a mirror polishing step for positioning the polishing blade on the outer periphery of the wafer held on the chuck table from which the chamfer has been removed, and rotating the chuck table while rotating the polishing blade to polish the cutting surface from which the chamfer has been removed into a mirror finish.

[0010] In the mirror-finishing step, it is preferable to polish the cut surface by supplying water or slurry. Also, it is preferable that the wafer is a bonded wafer in which the surface on which the effective area of ​​a first wafer is formed is bonded to a second wafer, and in the wafer holding step, the second wafer side is held on the chuck table, and the chamfer removing step and the mirror-finishing step are performed on the back surface of the first wafer of the wafer held on the chuck table. [Effects of the Invention]

[0011] The wafer processing method of the present invention includes a preparation step of preparing a processing apparatus including a chuck table for holding a wafer, cutting means having a rotatable cutting blade for cutting the chamfered portion of the wafer held on the chuck table, and polishing means having a rotatable polishing blade for polishing the surface from which the chamfered portion has been removed; a wafer holding step of holding a wafer on the chuck table; a chamfer removing step of positioning the cutting blade on an excess area on the outer periphery of the wafer held on the chuck table and rotating the chuck table while rotating the cutting blade to remove the chamfered portion; and a mirror polishing step of positioning the polishing blade on the outer periphery of the wafer held on the chuck table from which the chamfered portion has been removed, and rotating the chuck table while rotating the polishing blade to polish the cut surface from which the chamfered portion has been removed to a mirror finish.Therefore, after the chamfered portion is removed from the outer periphery of the wafer by the cutting means, the cut surface is mirror polished by the polishing means to eliminate any remaining portion. This eliminates problems such as the remaining portion falling off in a later process and becoming a source of contamination, or causing chipping of device chips when the wafer is divided into individual device chips. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an overall perspective view of a processing device according to an embodiment of the present invention; [Figure 2] 2A and 2B are a partially enlarged perspective view and an exploded perspective view of a processing means disposed in the processing apparatus shown in FIG. 1. [Figure 3]3A and 3B are a perspective view and an exploded perspective view showing a state in which the processing means shown in FIG. 2 is used as cutting means. [Figure 4] 3A and 3B are a perspective view and an exploded perspective view showing a state in which the processing means shown in FIG. 2 is used as a polishing means. [Figure 5] 2 is a perspective view showing a wafer W processed by the processing apparatus shown in FIG. 1. [Figure 6] FIG. 10 is a perspective view showing a wafer holding step of the present embodiment. [Figure 7] FIG. 1A is a perspective view showing an embodiment of a chamfered portion removing step; FIG. 1B is a perspective view showing a wafer from which a chamfered portion has been removed by the chamfered portion removing step shown in FIG. 1A; and FIG. 1B is an enlarged cross-sectional view of a portion of the outer periphery of the wafer shown in FIG. [Figure 8] FIG. 1(a) is a perspective view showing an embodiment of a mirror-finishing process, and FIG. 1(b) is an enlarged cross-sectional view of a part of the outer periphery of the wafer shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a wafer processing method according to the present invention will be described in detail with reference to the accompanying drawings.

[0014] The wafer processing method of the present invention includes a preparation step of preparing a processing device, a wafer holding step of holding a wafer on a chuck table of the processing device, a chamfer removal step of removing the chamfered portion of the wafer held on the chuck table, and a mirror processing step of polishing the cutting surface of the wafer held on the chuck table and from which the chamfered portion has been removed to a mirror finish. Each step will be described in more detail below.

[0015] (preparation process) The preparation process is a process of preparing a processing device that includes a chuck table that holds a wafer, which is the workpiece, a cutting means that has a rotatable cutting blade that cuts the chamfered portion of the wafer held on the chuck table, and a polishing means that has a rotatable polishing blade that polishes the surface from which the chamfered portion has been removed.With reference to Figure 1, the processing device 1 prepared by the preparation process of this embodiment will be described in more detail.

[0016] The processing apparatus 1 shown in Figure 1 has a housing 2 having an approximately rectangular parallelepiped shape, and is equipped with a cassette 4 placed on a cassette table 4a of the housing 2, a transfer means 3 for transferring the wafer W, which is the workpiece, from the cassette 4 to a temporary storage table 5, a transfer means 6 having a swivel arm for suctioning the wafer W transferred to the temporary storage table 5 and transferring it to a chuck table 7, a processing means 8 for processing the wafer W held on the chuck table 7, an imaging means 9 for imaging the wafer W held on the chuck table 7 and detecting the area to be processed by the processing means 8, a cleaning device 13 (details omitted) for cleaning and drying the processed wafer W, a cleaning and transfer means 14 for transferring the wafer W from the transfer position where the chuck table 7 is positioned in Figure 1 and transferring it to the cleaning device 13, and a control means, a display means, etc., which are not shown.

[0017] The suction chuck 7a, which constitutes the holding surface of the chuck table 7, is in an XY plane defined by the X-axis direction and the Y-axis direction perpendicular to the X-axis direction, and is substantially horizontal. The suction chuck 7a is made of a breathable material, and is connected to a suction means (not shown). Activating the suction means generates negative pressure in the suction chuck 7a. Inside the housing 2, there are arranged an X-axis feed means for moving the chuck table 7 in the X-axis direction, a Y-axis feed means for moving the processing means 8 in the Y-axis direction, a Z-axis feed means for moving the processing means 8 in the Z-axis direction (up and down), a rotary drive means for rotating the chuck table 7, and other components (none of which are shown).

[0018] FIG. 2 shows an enlarged view of the main components of the processing means 8 provided in the processing apparatus 1 shown in FIG. 1, with an exploded perspective view shown at the top. As shown, the processing means 8 includes a rotary shaft housing 81, a rotary shaft 84 rotatably supported by the rotary shaft housing 81, a cutting blade 83A (or abrasive blade 83B) fixed to the tip of the rotary shaft 84, and a blade cover 82 composed of multiple components that protects the cutting blade 83A. A pair of processing water supply nozzles 85 are provided on the blade cover 82 adjacent to each other across the cutting blade 83A. These nozzles supply processing water (e.g., pure water) introduced through processing water inlets 86, 86 provided on the blade cover 82 toward the cutting position. A rotary drive source consisting of an electric motor (not shown) is housed at the other end of the rotary shaft housing 81. The rotary drive source rotates the rotary shaft 84 to rotate the cutting blade 83A.

[0019] As can be seen from the exploded view shown at the top of Figure 2, the blade cover 82 is formed to include a fixed cover 82a fixed to the tip of the rotating shaft housing 81, a removable cover 82b attached to the tip of the fixed cover 82a by a screw 88a, and a blade detection block 82c attached to the top of the fixed cover 82a by a screw 88b for detecting the state of the cutting edge of the cutting blade 83A.

[0020] For convenience of explanation, Figures 3 and 4 show an oblique view and an exploded view of the processing means 8 with the blade cover 82 omitted. Figure 3 shows a state in which a cutting blade 83A is attached to the rotating shaft 84, and Figure 4 shows a state in which a polishing blade 83B is attached to the rotating shaft 84.

[0021] As can be seen from Fig. 3, the processing means 8 includes a rotary shaft 84 rotatably supported by a housing 81, a cutting blade 83A fixed to the tip of the rotary shaft 84, and a nut 87 for detachably fixing the cutting blade 83A to the tip of the rotary shaft 84. An annular flange 84a is provided on the rotary shaft 84, protruding radially outward, and a male screw 84b is formed on the outer circumferential surface of the rotary shaft 84 further on the tip side than the flange 84a.

[0022] The cutting blade 83A shown in FIG. 3 has an annular circular base 83Aa that can be made of an appropriate metal material such as an aluminum alloy, and an annular cutting blade 83Ab that protrudes radially outward from one end of the outer periphery of the circular base 83Aa. An attachment opening 83Ac is formed in the center of the circular base 83Aa, into which the tip of a rotating shaft 84 is inserted. The tip of the illustrated rotating shaft 84 is inserted into the attachment opening 83Ac of the circular base 83Aa, and the cutting blade 83A is brought into contact with the flange 84a. The nut 87 is then fastened to the male thread 84b of the rotating shaft 84. As a result, the cutting blade 83A is sandwiched between the flange 84a and the nut 87 and fixed to the tip of the rotating shaft 84.

[0023] The cutting blade 83A is rotatably supported via the rotating shaft 84 as described above, and is used to cut and remove the chamfered portion of the wafer W, as described below. The cutting edge 83Ab of the cutting blade 83A is, for example, a resin-bonded grinding wheel having a diameter of 50 mm and a thickness of 3 mm. Note that the cutting blade 83A is not limited to being a resin-bonded grinding wheel, and may be, for example, a vitrified grinding wheel or a metal-bonded grinding wheel. Furthermore, the diameter and thickness of the cutting blade 83A are not limited to the above dimensions, and are appropriately selected based on the diameter of the wafer W, the width of the chamfered portion 10C to be removed, and the like. When the cutting blade 83A is attached to the rotating shaft 84 as described above, the processing means 8 functions as the cutting means of the present invention.

[0024] As shown in FIG. 4, the processing tool 8 of this embodiment can be equipped with a polishing blade 83B, instead of the cutting blade 83A, for polishing the cutting surface of the wafer W from which the chamfered portion has been removed. The polishing blade 83B includes an annular circular base 83Ba, which may be formed from an appropriate metal material such as an aluminum alloy, and an annular polishing pad 83Bb protruding radially outward from one end of the outer circumferential surface of the circular base 83Ba. A mounting opening 83Bc is formed in the center of the circular base 83Ba, into which the tip of a rotating shaft 84 is inserted. The tip of the illustrated rotating shaft 84 is inserted into the mounting opening 83Bc of the circular base 83Ba, and the polishing blade 83B abuts against the flange 84a. The nut 87 is then fastened to the male thread 84b of the rotating shaft 84. The polishing blade 83B is thus sandwiched between the flange 84a and the nut 87 and fixed to the tip of the rotating shaft 84, functioning as the polishing tool of the present invention. The polishing pad 83Bb of the polishing blade 83B is made of, for example, porous urethane mixed with silica, and has a diameter of 50 mm and a thickness of 3 mm.

[0025] As described above, the processing means 8 of this embodiment serves as both the cutting means and the polishing means of the present invention, and by being equipped with the above-mentioned processing means 8, the processing device 1 can be said to be equipped with the cutting means and the polishing means of the present invention.

[0026] The processing device 1 of this embodiment generally has the configuration as described above, and the preparation step of this embodiment is completed by preparing the processing device 1 as described above.

[0027] (Wafer holding process) After the above-described preparation step is performed, a wafer holding step is performed in which the wafer W as the workpiece is held on the chuck table 7 of the processing device 1.

[0028] As shown in FIG. 5, the wafer W processed by the processing apparatus 1 of this embodiment is, for example, a bonded wafer formed by bonding a first wafer 10 and a second wafer 12. As shown in the figure, the first wafer 10 has a surface 10a on which a plurality of devices D are formed, partitioned by planned division lines L. The surface 10a of the wafer 10 is formed with a central effective area 10A including a device region in which the plurality of devices D are formed, and a peripheral excess area 10B having a chamfered portion 10C formed on the periphery surrounding the effective area 10A. Note that, although FIG. 5 depicts a circular division line 16 (shown by a two-dot chain line) dividing the effective area 10A and the peripheral excess area 10B, the division line 16 is depicted for convenience of explanation and is not actually drawn on the surface 10a of the first wafer 10.

[0029] The second wafer 12 to be bonded to the first wafer 10 described above has substantially the same configuration as the first wafer 10, and as shown in FIG. 5, a plurality of devices D are formed on the front surface 12a, partitioned by the planned division lines L. As shown in the figure, the wafer W is obtained by inverting the first wafer 10 so that the back surface 10b faces upward and the front surface 10a faces downward, and bonding the front surface 10a of the first wafer 10 to the front surface 12a of the second wafer 12 by an appropriate bonding method. Note that the bonding method for bonding the first wafer 10 and the second wafer 12 is not particularly limited. For example, the insulating film on the surface may be hydrophilized by a surface activation treatment, and the front surface 10a of the first wafer 10 and the front surface 12a of the second wafer 12 may be bonded by forming a siloxane bond at the bonding surfaces by pressure bonding, or by bonding using an appropriate adhesive.

[0030] The wafer processed by the wafer processing method of this embodiment is not limited to the above-described wafer W, and may be, for example, a single first wafer 10 shown in FIG.

[0031] In the wafer holding step of this embodiment, the above-mentioned carry-in / out means 3 is operated to carry out the wafer W from the cassette 4 to the temporary placement table 5 for alignment, the transport means 6 is operated to suck the wafer W on the temporary placement table 5, and as shown in FIG. 6, the back surface 12b of the second wafer 12 of the above-mentioned wafer W is placed on the suction chuck 7a of the chuck table 7 with the back surface 12b facing downward, and the suction means (not shown) is operated to generate negative pressure in the suction chuck 7a to hold the wafer W by suction. Note that when the workpiece is a single wafer (first wafer 10), the back surface 10b is placed facing downward and held by suction, as shown on the left side of FIG. 6. In the embodiment described below, the wafer W obtained by bonding the first wafer 10 and the second wafer 12 is held on the chuck table 7.

[0032] (chamfered portion removal process) When carrying out the chamfered portion removal process described below, as explained based on Figure 3, the above-mentioned cutting blade 83A is attached to the rotation shaft 84 of the processing means 8, and the processing means 8 constitutes the cutting means.

[0033] After the wafer holding step is performed, the wafer W is positioned directly below the imaging means 9 and imaged by an X-axis feed means (not shown). Alignment is performed to detect the outer periphery of the wafer W, and positional information of the chamfered portion 10C to be removed from the wafer W is detected. Next, based on the positional information of the chamfered portion 10C to be removed detected by the imaging means 9, the X-axis feed means and the Y-axis feed means are operated to position the cutting blade 83A in the outer periphery excess region 10B of the first wafer 10 of the wafer W held on the chuck table 7, as shown in FIG. 7(a). For ease of explanation, the blade cover 82 is omitted from the illustration of the processing means 8 in FIG. 7 and FIG. 8 (described later). Next, the cutting blade 83A is rotated in the direction indicated by arrow R1 at a predetermined rotational speed (e.g., 30,000 rpm), and the chuck table 7 is rotated in the direction indicated by arrow R2 at a predetermined rotational speed (e.g., 1 rpm).

[0034] Then, processing water (e.g., pure water) is supplied to the cutting region from the processing water supply nozzle 85, and the Z-axis feed means is operated to feed the processing means 8 in the direction indicated by arrow R3 in Fig. 7(a) by the thickness of the first wafer 10 to perform cutting, and the chamfered portion 10C of the first wafer 10 is removed in an annular shape, completing the chamfer removing step, as shown in Fig. 7(b). Here, when the chamfered portion 10C is removed by the cutting blade 83A, the cut surface 10d from which the chamfered portion 10C of the first wafer 10 has been removed becomes rough, and a portion of it remains, as shown in Fig. 7(c). Furthermore, because the incision feed amount is set so as not to cut the second wafer 12, a portion of the first wafer 10 remains on the surface 12a of the second wafer 12 to which the chamfered portion 10C of the first wafer 10 was bonded. After the chamfer removing step is performed on the wafer W as described above, the cleaning and carrying-out means 14 is operated to transport the wafer W held on the chuck table 7 to the cleaning device 13, where cleaning and drying of the wafer W are performed. Next, the transport means 6 and the carrying-in / out means 3 are operated to store the wafer W from which the chamfer 10C has been removed in a predetermined position in the cassette 4. Note that in the chamfer removing step of this embodiment, the chamfer removing step is performed on all wafers W stored in the cassette 4, and then the mirror polishing step described below is performed on the wafer W from which the chamfer has been removed.

[0035] (Mirror finishing process) When performing the mirror-finishing process of this embodiment, as explained based on FIG. 4, a polishing blade 83B is attached to the processing means 8 instead of the cutting blade 83A to serve as a polishing means. Next, a wafer holding process is performed in which the wafer W, from which the chamfered portion 10C of the first wafer 10 has been removed in the chamfered portion removing process, is held on the chuck table 7. This wafer holding process is performed in the same manner as the wafer holding process performed before the chamfered portion removing process, and therefore a detailed description thereof will be omitted. Then, alignment is performed using the imaging means 9 to detect the position of the outer periphery of the first wafer 10, from which the chamfered portion 10C has been removed and the cut surface 10d has been formed.

[0036] Next, the X-axis feed means and Y-axis feed means are operated based on position information relating to the outer periphery on which the cut surface 10d of the first wafer 10 is formed, and the polishing blade 83B is positioned above the first wafer 10 of the wafers W held on the chuck table 7. Next, as shown in Fig. 8(a), the polishing blade 83B is rotated in the direction indicated by arrow R1 at a predetermined rotational speed (e.g., 3000 rpm) that is slower than that used in the chamfer removing step, and the chuck table 7 is rotated in the direction indicated by arrow R2 at a predetermined rotational speed (e.g., 1 rpm).

[0037] Here, the processing water supply nozzle 85 supplies polishing slurry to the polishing area instead of the processing water, and the Z-axis feed means (not shown) is operated to lower the processing means 8 in the direction indicated by arrow R3, bringing the polishing blade 83B into contact with the cut surface 10d of the first wafer 10 and the front surface 12a of the second wafer 12 from which the chamfered portion 10C has been removed, thereby polishing the wafer. Then, by performing the polishing for a predetermined time, as shown in FIG. 8(b), the roughness of the cut surface 10d of the first wafer 10 is eliminated, and the remaining portion of the front surface 12a of the second wafer 12 is removed to achieve a mirror finish, thereby completing the mirror finish process of this embodiment. Depending on the type of polishing pad 83Bb constituting the polishing blade 83B (e.g., whether it contains fine abrasive grains), processing water (pure water) may be supplied directly from the processing water supply nozzle 85 to the polishing area instead of supplying slurry. Furthermore, when polishing slurry is supplied when the polishing process is performed, a dedicated nozzle for supplying the polishing slurry to the polishing region may be provided instead of the processing water supply nozzle 85. After the mirror-finishing process has been performed in this manner, the cleaning and carrying-out means 14 is operated to transport the wafer W held on the chuck table 7 to the cleaning device 13, where cleaning and drying of the wafer W are performed. Next, the transport means 6 and the carrying-in / out means 3 are operated to store the mirror-finished wafer W at a predetermined position in the cassette 4, thereby completing the wafer processing method of this embodiment.

[0038] According to the embodiment described above, after the chamfered portion 10C is removed from the outer periphery of the wafer W by the cutting means, the cut surface 10d is mirror-finished by the polishing means, thereby eliminating any remaining portion. This eliminates problems such as the remaining portion falling off in a later process and becoming a source of contamination, or causing chipping of device chips when the wafer W is divided into individual device chips.

[0039] The wafer processed in the above-described embodiment was a wafer W formed by bonding a first wafer 10 and a second wafer 12 together, but the wafer processed by the wafer processing method of the present invention is not limited to a bonded wafer and may be a single wafer (for example, only the first wafer 10).

[0040] Furthermore, in the above-described embodiment, the cutting blade 83A and the polishing blade 83B are selectively attached to the processing means 8 arranged in the processing device 1 prepared in the preparation process, so that one processing means 8 serves as both a cutting means and a polishing means. However, for example, the processing device 1 may be configured to have both a cutting means and a polishing means, and the chamfer removal process and the mirror polishing process may be carried out consecutively. [Explanation of symbols]

[0041] 1: Processing equipment 2: Housing 3: Carrying in / out means 4: Cassette 5: Temporary table 6: Means of transport 7: Chuck table 7a: Suction chuck 8: Processing means 81: Rotating shaft housing 82: Blade cover 83A: Cutting blade 83B: Abrasive blade 84: Rotation axis 84a: flange 84b: Male thread 85: Processing water supply nozzle 86: Processing water introduction part 87: Nut 9: Imaging means 10: First wafer 10a: surface 10b: Back side 10d: Cutting surface 10A: Effective area 10B: Surplus outer area 10C: Chamfered part 12: Second wafer 12a: Surface 12b: Back 13: Cleaning equipment 14: Cleaning and carrying out means W: Wafer

Claims

1. A method for processing a wafer having an effective area including a device area in which a plurality of devices are partitioned by planned division lines, and an outer peripheral excess area in which a chamfered portion surrounding the effective area is formed, comprising: a preparation step of preparing a processing device including a chuck table for holding a wafer, cutting means having a rotatable cutting blade for cutting a chamfered portion of the wafer held on the chuck table, and polishing means having a rotatable polishing blade for polishing a surface from which the chamfered portion has been removed; a wafer holding step of holding the wafer on the chuck table; a chamfer removing step of positioning the cutting blade in the peripheral excess region of the wafer held on the chuck table and rotating the chuck table while rotating the cutting blade to remove the chamfer; a mirror-finishing step in which the polishing blade is positioned on the outer periphery of the wafer held on the chuck table from which the chamfered portion has been removed, and the chuck table is rotated while the polishing blade is rotated to polish the cut surface from which the chamfered portion has been removed into a mirror-finish; A wafer processing method comprising the steps of:

2. 2. The wafer processing method according to claim 1, wherein in the mirror finishing step, the cut surface is polished by supplying water or slurry.

3. the wafer is a bonded wafer in which a surface of a first wafer on which an effective area is formed is bonded to a second wafer; In the wafer holding step, the second wafer side is held on the chuck table; 3. The wafer processing method according to claim 1, wherein the chamfer removing step and the mirror polishing step are carried out on a first wafer of the wafers held on the chuck table.

Images