Processing method and processing apparatus

Abstract

This method can suppress the occurrence of cracks when removing protrusions on the outer edge of the wafer. [Solution] The processing method comprises a cutting step 1002 in which a first cutting blade cuts into the boundary between a circular recess and an annular protrusion of the wafer, and a second cutting blade cuts into the annular protrusion of the wafer, and a processing step 1003 in which, with the first cutting blade cutting into the boundary and the second cutting blade cutting into the annular protrusion, the wafer is moved relative to the first cutting blade and the second cutting blade, thereby performing annular processing on the boundary with the first cutting blade and annular processing on the annular protrusion with the second cutting blade, wherein the first cutting blade and the second cutting blade each contain abrasive grains, and the average abrasive grain size of the first cutting blade is smaller than the average abrasive grain size of the second cutting blade.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for processing a wafer.

Background Art

[0002] For example, a wafer thinned to a thickness of 50 μm or less is likely to be warped or deflected, making handling difficult. Therefore, in some cases, only the central portion of the wafer is ground to form a concave portion, and the thickness of the outer peripheral portion is left intact to form a convex portion surrounding the concave portion as reinforcement.

[0003] After such a wafer has been processed, such as film formation or inspection, the convex portion is removed. A method of removing the convex portion with a cutting blade has been disclosed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when cutting an object to be processed in a circular shape with a cutting blade, the cutting blade is subjected to a greater processing load than when cutting linearly, and chipping, cracking, etc. are likely to occur.

[0006] Particularly, if a crack progresses toward the concave portion side, the device may be damaged, and further improvement is eagerly desired.

[0007] An object of the present invention is to provide a processing method and a processing apparatus capable of suppressing the occurrence of cracks when removing a convex portion on the outer periphery of a wafer.

Means for Solving the Problems

[0008] To solve the above-mentioned problems and achieve the objective, the present invention provides a processing method for a wafer having a recess formed in the center and a convex portion surrounding the recess, comprising: a cutting step of cutting the boundary between the recess and the convex portion of the wafer with a first grinding wheel and cutting the convex portion of the wafer with a second grinding wheel; and a processing step of moving the wafer relative to the first grinding wheel and the second grinding wheel while the first grinding wheel has cut the boundary and the second grinding wheel has cut the convex portion, thereby performing annular processing on the boundary with the first grinding wheel and annular processing on the convex portion with the second grinding wheel, wherein the first grinding wheel and the second grinding wheel each contain abrasive grains, and the average abrasive grain size of the first grinding wheel is smaller than the average abrasive grain size of the second grinding wheel.

[0009] In the processing method described above, after performing the processing step, a re-cutting step is performed in which the first grinding wheel cuts deeper into the boundary portion than in the cutting step and the second grinding wheel cuts deeper into the protrusion portion than in the cutting step, and a re-processing step is performed in which, with the first grinding wheel having cut deeper into the boundary portion than in the cutting step and the second grinding wheel having cut deeper into the protrusion portion than in the cutting step, the wafer is moved relative to the first grinding wheel and the second grinding wheel to perform annular processing on the boundary portion and the protrusion portion. After the processing step, the re-cutting step and the re-processing step may each be repeated one or more times to cut the boundary portion with the first grinding wheel and cut the protrusion portion with the second grinding wheel.

[0010] In the processing method described above, in the cutting step, the first grinding wheel may be made to cut into the wafer to a depth such that the first grinding wheel completely cuts the wafer in the thickness direction, and the second grinding wheel may be made to cut into the wafer to a depth such that the second grinding wheel completely cuts the wafer in the thickness direction.

[0011] In the processing method described above, after performing the processing step, a re-cutting step is performed in which the first grinding wheel is made to cut into the wafer at a position different from the cutting step in the radial direction of the wafer, and the second grinding wheel is made to cut into the wafer at a position different from the cutting step in the radial direction of the wafer, and a re-processing step is performed in which, with the first grinding wheel having cut into a position different from the cutting step in the radial direction of the wafer and the second grinding wheel having cut into a position different from the cutting step in the radial direction of the wafer, the wafer is moved relative to the first grinding wheel and the second grinding wheel is made to perform annular processing on the boundary portion and annular processing on the convex portion, and after the processing step, the re-cutting step and the re-processing step may be repeated one or more times each to separate the recess from the convex portion with the second grinding wheel and remove the convex portion with the second grinding wheel.

[0012] In the above processing method, the recess is formed on the back surface of the wafer surface and a tape is placed on the back surface of the wafer, and in the cutting step, the first grinding wheel and the second grinding wheel may be used to cut to a depth from the surface of the wafer to the tape.

[0013] The above processing method may include a residual portion detection step in which, after performing the processing step, the protrusion is imaged and the remaining portion of the protrusion in the radial direction of the wafer is detected.

[0014] The processing apparatus of the present invention is a processing apparatus for processing a wafer having a recess formed in the center and a protrusion surrounding the recess, comprising: a holding unit for holding the wafer; a first grinding wheel for cutting into the boundary between the recess and the protrusion of the wafer held by the holding unit; a second grinding wheel for cutting into the protrusion of the wafer held by the holding unit; and a moving unit for moving the wafer relative to the first grinding wheel and the second grinding wheel while the first grinding wheel is cutting into the boundary and the second grinding wheel is cutting into the protrusion, wherein the first grinding wheel and the second grinding wheel each contain abrasive grains, and the average abrasive grain size of the first grinding wheel is smaller than the average abrasive grain size of the second grinding wheel. [Effects of the Invention]

[0015] The present invention has an effect of suppressing the occurrence of cracks when removing the convex portions on the outer periphery of a wafer.

Brief Description of the Drawings

[0016] [Figure 1] FIG. 1 is a perspective view showing a configuration example of a processing apparatus according to Embodiment 1. [Figure 2] FIG. 2 is a perspective view schematically showing the configuration of a wafer to be processed by the processing apparatus shown in FIG. 1. [Figure 3] FIG. 3 is a front view schematically showing a partial cross section of a cutting unit and a chuck table of the processing apparatus shown in FIG. 1. [Figure 4] FIG. 4 is a flowchart showing the flow of a processing method according to Embodiment 1. [Figure 5] FIG. 5 is a cross-sectional view schematically showing a holding step of the processing method shown in FIG. 4. [Figure 6] FIG. 6 is a front view schematically showing a partial cross section of a cutting step of the processing method shown in FIG. 4. [Figure 7] FIG. 7 is a front view schematically showing a partial cross section of a processing step of the processing method shown in FIG. 4. [Figure 8] FIG. 8 is a plan view schematically showing a processing step of the processing method shown in FIG. 4. [Figure 9] FIG. 9 is a flowchart showing the flow of a processing method according to Embodiment 2. [Figure 10] FIG. 10 is a front view schematically showing a partial cross section of a holding step of the processing method shown in FIG. 9. [Figure 11] FIG. 11 is a front view schematically showing a partial cross section of a cutting step of the processing method shown in FIG. 9. [Figure 12] FIG. 12 is a front view schematically showing a partial cross section of a re-cutting and re-processing step of the processing method shown in FIG. 9. [Figure 13]FIG. 13 is a front view schematically showing a cutting step of the processing method according to Embodiment 3 in a partial cross section. [Figure 14] FIG. 14 is a front view schematically showing a processing step of the processing method according to Embodiment 3 in a partial cross section. [Figure 15] FIG. 15 is a flowchart showing the flow of the processing method according to a modification of Embodiment 3. [Figure 16] FIG. 16 is a perspective view showing a configuration example of the processing apparatus according to Embodiment 4. [Figure 17] FIG. 17 is a flowchart showing the flow of the processing method according to Embodiment 4. [Figure 18] FIG. 18 is a front view schematically showing a holding step of the processing method shown in FIG. 17 in a partial cross section. [Figure 19] FIG. 19 is a cross-sectional view showing an enlarged view of part XVIII in FIG. 18. [Figure 20] FIG. 20 is a front view schematically showing a processing step of the processing method shown in FIG. 17 in a partial cross section. [Figure 21] FIG. 21 is a cross-sectional view schematically showing the locus of the cutting edge of the cutting blade during the processing step of the processing method shown in FIG. 17. [Figure 22] FIG. 22 is a cross-sectional view schematically showing a remaining part detection step of the processing method shown in FIG. 17. [Figure 23] FIG. 23 is a cross-sectional view schematically showing a state where the processing step of the processing method shown in FIG. 17 is completed. [Figure 24] FIG. 24 is a flowchart showing the flow of the processing method according to a modification of Embodiment 4.

DETAILED DESCRIPTION OF THE INVENTION

[0017] 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.

[0018] [Embodiment 1] A processing apparatus according to Embodiment 1 of the present invention will be described based on the drawings. Figure 1 is a perspective view showing an example of the configuration of the processing apparatus according to Embodiment 1. Figure 2 is a schematic perspective view showing the configuration of a wafer to be processed by the processing apparatus shown in Figure 1. Figure 3 is a schematic front view showing a partial cross-section of the cutting unit and chuck table of the processing apparatus shown in Figure 1.

[0019] (wafer) The processing apparatus 1 shown in Figure 1 according to Embodiment 1 is an apparatus for processing the wafer 200 shown in Figure 2. The wafer 200 to be processed by the processing apparatus 1 according to Embodiment 1 is a disc-shaped semiconductor wafer or optical device wafer with a substrate made of silicon, sapphire, gallium, etc. As shown in Figure 2, the wafer 200 has a device region 202 on its surface 201 and an outer peripheral excess region 203 surrounding the device region 202.

[0020] The device region 202 has division lines 204 arranged in a grid pattern on the surface 201, and devices 205 formed in each region partitioned by the division lines 204.

[0021] Device 205 is, for example, an integrated circuit such as an IC (Integrated Circuit) or LSI (Large Scale Integration), an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), a MEMS (Micro Electro Mechanical Systems), or a semiconductor memory (semiconductor storage device). The outer peripheral surplus region 203 surrounds the device region 202 all around and is the region on the surface 201 where device 205 is not formed.

[0022] Furthermore, in Embodiment 1, the wafer 200 is a so-called TAIKO® wafer, in which the center of the back surface 206 on the back side of the surface 201 of the device region 202 is ground by a well-known grinding apparatus, and as shown in Figure 2, a circular recess 210 (corresponding to a recess) is formed in the center of the back surface 206 on the back side of the surface 201 and on the back surface 206 side of the device region 202, and an annular protrusion 211 (corresponding to a protrusion) is formed on the back surface 206 side of the outer peripheral excess region 203 surrounding the circular recess 210.

[0023] The circular recess 210 is formed in the region of the back surface 206 that overlaps with the device region 202 in the thickness direction, and the annular protrusion 211 is formed in the region of the back surface 206 that overlaps with the outer peripheral excess region 203 in the thickness direction. The annular protrusion 211 is formed to be thicker than the device region 202.

[0024] Thus, the back surface 206 of the wafer 200 has a circular recess 210 formed in the center and an annular protrusion 211 surrounding the circular recess 210, creating a step between the device region 202 and the outer peripheral excess region 203. Furthermore, the front surface 201 of the wafer 200 is formed on the same plane across the device region 202 and the outer peripheral excess region 203.

[0025] Furthermore, in Embodiment 1, the circular recess 210 of the wafer 200 consists of a first recess 210-1 formed by grinding with a rough grinding wheel, as shown in Figure 5, and a second recess 210-2 formed to have a smaller diameter than the first recess 210-1 by grinding the bottom of the first recess 210-1 with a finish grinding wheel, and a stepped portion 210-3 is formed between the first recess 210-1 and the second recess 210-2. The bottom surface of the second recess 210-2 is the bottom surface 212 of the circular recess 210.

[0026] After the annular protrusion 211 is removed from the aforementioned wafer 200, it is divided into individual devices 205 along the division line 204.

[0027] (Processing equipment) The processing apparatus 1 according to Embodiment 1 is an apparatus for removing an annular protrusion 211 from a wafer 200 by holding it in a holding unit 10. As shown in Figure 1, the processing apparatus 1 comprises a holding unit 10 that holds the wafer 200 by suction on a holding surface 11, a cutting unit 20 that cuts the wafer 200 held in the holding unit 10 with a cutting blade 21, an imaging unit 30 that images the wafer 200 held in the holding unit 10, and a controller 100.

[0028] Furthermore, as shown in Figure 1, the processing apparatus 1 includes a moving unit 40 that moves the holding unit 10 and the cutting unit 20 relative to each other. The moving unit 40 includes at least an X-axis moving unit 41, which is a processing feed unit that feeds the holding unit 10 in the X-axis direction parallel to the horizontal direction; a Y-axis moving unit 42, which is an indexing feed unit that feeds the cutting unit 20 in the Y-axis direction parallel to the horizontal direction and perpendicular to the X-axis direction; a Z-axis moving unit 43, which is a cutting feed unit that feeds the cutting unit 20 in the Z-axis direction parallel to the vertical direction and perpendicular to both the X-axis and Y-axis directions; and a rotational moving unit 44 that rotates the holding unit 10 around an axis parallel to the Z-axis direction.

[0029] As shown in Figure 1, the processing apparatus 1 is equipped with two cutting units 20, that is, a two-spindle dicer, a so-called facing dual-type cutting apparatus. Hereinafter, one cutting unit 20 will be referred to as the first cutting unit 20-1, and the other cutting unit 20 as the second cutting unit 20-2. The moving unit 40 of the processing apparatus 1 is equipped with two Y-axis moving units 42 and two Z-axis moving units 43, and these two Y-axis moving units 42 and Z-axis moving units 43 correspond to cutting units 20-1 and 20-2, respectively.

[0030] The X-axis movement unit 41 is installed on the main body 2 of the apparatus. The X-axis movement unit 41 moves the holding unit 10 together with the rotational movement unit 44 in the X-axis direction, which is the machining feed direction, thereby feeding the holding unit 10 along the X-axis direction to the first cutting unit 20-1 and the second cutting unit 20-2.

[0031] The Y-axis movement unit 42 is installed on a gate-shaped support frame 3 that is erected from the main body of the apparatus 2. The Y-axis movement unit 42 moves the corresponding cutting units 20-1 and 20-2 in the Y-axis direction relative to the holding unit 10 that holds the wafer 200.

[0032] The Z-axis movement unit 43 is installed on a moving frame 4 which is moved in the Y-axis direction by the Y-axis movement unit 42. The Z-axis movement unit 43 moves the corresponding cutting units 20-1 and 20-2 in the Z-axis direction relative to the holding unit 10 which holds the wafer 200.

[0033] The X-axis moving unit 41, Y-axis moving unit 42, and Z-axis moving unit 43 are equipped with a well-known ball screw rotatably mounted around its axis, a well-known motor for rotating the ball screw around its axis, and a well-known guide rail for supporting the holding unit 10 or cutting units 20-1, 20-2 so that they can move in the X-axis, Y-axis, or Z-axis direction. The rotary moving unit 44 is equipped with a well-known motor for rotating the holding unit 10 around its axis.

[0034] The holding unit 10 is disc-shaped, and its holding surface 11, which is parallel to the horizontal direction and holds the wafer 200, is formed from porous ceramic or the like. The holding unit 10 is also provided to move freely in the X-axis direction by an X-axis moving unit 41 across the processing area below the cutting units 20-1 and 20-2 and the loading / unloading area where the wafer 200 is loaded and unloaded, separated from below the cutting units 20-1 and 20-2, and is also provided to rotate freely around an axis parallel to the Z-axis direction by a rotational moving unit 44.

[0035] As shown in Figure 3, the holding unit 10 has a holding surface 11 connected to a suction source 13 via an on-off valve 12. When the on-off valve 12 opens and the holding surface 11 is sucked by the suction source 13, the wafer 200 placed on the holding surface 11 is held in place by suction.

[0036] The cutting units 20-1 and 20-2 are cutting units to which cutting blades 21 for cutting wafers 200 held by the holding unit 10 are detachably mounted. Each of the cutting units 20-1 and 20-2 is attached to a second moving frame 5 that is movable in the Z-axis direction by a corresponding Z-axis moving unit 43, and is provided to be movable in the Y-axis direction by a Y-axis moving unit 42 and also movable in the Z-axis direction by a Z-axis moving unit 43 relative to the wafer 200 held by the holding unit 10. The cutting units 20-1 and 20-2 can position the cutting blades 21 at any position on the holding surface 11 of the holding unit 10 by the Y-axis moving unit 42 and the Z-axis moving unit 43.

[0037] As shown in Figure 3, the cutting units 20-1 and 20-2 each include a cutting blade 21, a spindle housing 22 attached to the lower end of the second moving frame 5 and provided to be movable in the Y-axis and Z-axis directions by a Y-axis moving unit 42 and a Z-axis moving unit 43, a spindle 23 which serves as a rotation axis and is provided in the spindle housing 22 so as to be rotatable around its axis, a spindle motor (not shown) that rotates the spindle 23 around its axis, and a cutting fluid supply nozzle 24 that supplies cutting fluid to the cutting blade.

[0038] The cutting blade 21 is an extremely thin cutting wheel having a substantially ring shape for cutting the wafer 200. In Embodiment 1, the cutting blade 21 is a so-called hub blade having an annular cutting edge 25 (shown in Figure 3) for cutting the wafer 200 and an annular base on which the cutting edge 25 is provided at the outer edge 213. The cutting edge 25 contains abrasive grains such as diamond or CBN (Cubic Boron Nitride) and a bonding material (binder) such as metal or resin, and is formed to a predetermined thickness. In this invention, the cutting blade 21 may also be a so-called washer blade consisting only of the cutting edge 25.

[0039] Hereinafter, the cutting blade 21 of the first cutting unit 20-1 will be referred to as the first cutting blade 21-1 (corresponding to the first grinding wheel), and the processing device 1 of the second cutting unit 20-2 will be referred to as the second cutting blade 21-2 (corresponding to the second grinding wheel). For this purpose, the cutting edges 25 of the first cutting blade 21-1 and the second cutting blade 21-2 each contain abrasive grains.

[0040] In Embodiment 1, the average particle size of the abrasive grains on the cutting edge 25 of the first cutting blade 21-1 (corresponding to the average abrasive particle size, which is the so-called number average, length average, area average, volume average, etc.) is smaller than the average particle size of the abrasive grains on the cutting edge 25 of the second cutting blade 21-2. Also in Embodiment 1, the thickness of the cutting edge 25 of the first cutting blade 21-1 is thinner than the thickness of the cutting edge 25 of the second cutting blade 21-2, as shown in Figure 3. Furthermore, in Embodiment 1, the thickness of the cutting edge 25 of the second cutting blade 21-2 is such that the annular protrusion 211 can be removed by cutting into the annular protrusion 211 with the cutting edge 25 of the second cutting blade 21-2 and rotating the holding unit 10 once around its axis.

[0041] The spindle housing 22 is attached to the lower end of the second moving frame 5 and is supported so as to be movable in the Z-axis direction by the Z-axis moving unit 43, and is also supported so as to be movable in the Y-axis direction by the Y-axis moving unit 42 via the Z-axis moving unit 43 and the moving frame 4. The spindle housing 22 houses the portion of the spindle 23 excluding the tip and a spindle motor (not shown), and supports the spindle 23 so as to be rotatable around its axis.

[0042] The spindle 23 has a cutting blade 21 detachably fixed to its tip. The spindle 23 is rotated by a spindle motor (not shown), and the cutting blade 21 is mounted on its tip. The axes of the spindle 23 and cutting blades 21-1 and 21-2 of the cutting units 20-1 and 20-2 are parallel to the Y-axis direction.

[0043] The imaging unit 30 images the wafer 200 held by the holding unit 10 and acquires the image. The imaging unit 30 is fixed to the first cutting unit 20-1 so as to move integrally with the first cutting unit 20-1. The imaging unit 30 is equipped with an image sensor that images the area of ​​the wafer 200 to be cut before cutting, which is held by the holding unit 10. The image sensor is, for example, a CCD (Charge-Coupled Device) image sensor or a CMOS (Complementary MOS) image sensor. The imaging unit 30 images the wafer 200 held by the holding unit 10 to acquire an image for performing alignment, such as aligning the wafer 200 with the cutting blade 21, and outputs the acquired image to the controller 100.

[0044] Furthermore, the processing apparatus 1 includes an X-axis position detection unit (not shown) for detecting the position of the holding unit 10 in the X-axis direction, a Y-axis position detection unit (not shown) for detecting the positions of the cutting units 20-1 and 20-2 in the Y-axis direction, and a Z-axis position detection unit for detecting the positions of the cutting units 20-1 and 20-2 in the Z-axis direction. The X-axis position detection unit and the Y-axis position detection unit can be configured with a linear scale parallel to the X-axis direction or the Y-axis direction, and a reading head. The Z-axis position detection unit detects the Z-axis position of the cutting units 20-1 and 20-2 using motor pulses.

[0045] The X-axis position detection unit, the Y-axis position detection unit, and the Z-axis position detection unit output the position of the holding unit 10 in the X-axis direction, and the position of the cutting units 20-1 and 20-2 in the Y-axis direction or Z-axis direction to the controller 100. The angle detection unit outputs the angle of the holding unit 10 around its axis from a reference position to the controller 100. In Embodiment 1, the X-axis, Y-axis, and Z-axis positions of each component of the processing apparatus 1 are determined based on a predetermined reference position (not shown).

[0046] Furthermore, the processing apparatus 1 includes a cassette elevator 50 on which a cassette 6 containing wafers 200 before and after cutting is placed and which moves the cassette 6 in the Z-axis direction, a cleaning unit 51 for cleaning the wafers 200 after cutting, and a transport unit (not shown) for transporting the wafers 200 between the cassette 6, the holding unit 10, and the cleaning unit 51.

[0047] The controller 100 controls each component of the processing apparatus 1 to cause the processing apparatus 1 to perform processing operations on the wafer 200. The controller 100 is a computer having an arithmetic processing unit with a microprocessor such as a CPU (central processing unit), a storage device with memory such as ROM (read-only memory) or RAM (random access memory), and an input / output interface device. The arithmetic processing unit of the controller 100 performs calculations according to the computer program stored in the storage device and outputs control signals for controlling the processing apparatus 1 to each component of the processing apparatus 1 via the input / output interface device.

[0048] The controller 100 is connected to a display unit (not shown) which consists of a liquid crystal display device that displays the status of the machining operation and captured images, an input unit (not shown) used by the operator to register machining conditions, and a notification unit (not shown). The input unit includes a touch panel provided on the display unit. The notification unit notifies the operator by emitting at least one of sound, light, and / or a display, and may also function as the display unit.

[0049] (Processing method) Next, the processing method according to Embodiment 1 will be described. Figure 4 is a flowchart showing the flow of the processing method according to Embodiment 1. The processing method according to Embodiment 1 is a method for removing the annular protrusion 211 from the wafer 200 described above. The processing method according to Embodiment 1 is carried out by the processing apparatus 1 with the configuration described above. That is, the processing method according to Embodiment 1 is also the processing operation of the processing apparatus 1 with the configuration described above.

[0050] In the processing apparatus 1, a cassette 6 containing multiple wafers 200 is placed on a cassette elevator 50, and the controller 100 receives processing conditions input by the operator from an input unit, etc., and stores the processing conditions in a storage device. In Embodiment 1, the wafer 200 has a protective tape 220 (shown in Figure 5) with the same diameter as the device area 202 attached to the device area 202 of the surface 201, and is housed in the cassette 6 with the back surface 206, i.e., the circular recess 210, facing upward. When the controller 100 receives a processing start instruction input by the operator from an input unit, etc., the processing apparatus 1 starts the processing operation, i.e., the processing method according to the embodiment. The processing method according to Embodiment 1 comprises a holding step 1001, a cutting step 1002, and a processing step 1003, as shown in Figure 4.

[0051] (Holding step) Figure 5 is a schematic cross-sectional view showing the holding step of the processing method shown in Figure 4. The holding step 1001 is the step of holding the surface 201 side of the wafer 200 on the holding surface 11 of the holding unit 10.

[0052] In Embodiment 1, during the holding step 1001, the processing apparatus 1 has a controller 100 that starts the rotation of the spindles 23 of each cutting unit 20-1, 20-2, i.e., the cutting blades 21-1, 21-2, and starts supplying cutting fluid to the cutting blades 21-1, 21-2. In Embodiment 1, during the holding step 1001, the processing apparatus 1 has a controller 100 that controls the cassette elevator 50 and transport unit, etc., to remove one wafer 200 before processing from the cassette 6 and place the wafer 200 with its surface 201 side on the holding surface 11 of the holding unit 10 positioned in the loading / unloading area, via a protective tape 220.

[0053] In Embodiment 1, during the holding step 1001, the processing apparatus 1, with the controller 100, opens the on / off valve 12 as shown in Figure 5, and holds the surface 201 of the wafer 200 to the holding surface 11 of the holding unit 10 positioned in the loading / unloading area via the protective tape 220.

[0054] (Cutting step) Figure 6 is a schematic front view showing a partial cross-section of the cutting step of the processing method shown in Figure 4. The cutting step 1002 is a step in which the first cutting blade 21-1 cuts into the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200, and the second cutting blade 21-2 cuts into the annular protrusion 211 of the wafer 200.

[0055] In Embodiment 1, during the cutting step 1002, the processing apparatus 1 uses the controller 100 to control the moving unit 40 to position the holding unit 10, which holds the wafer 200, in the processing area, and has the imaging unit 30 image the wafer 200. Based on the image acquired and the processing conditions, the processing apparatus 1 performs alignment. In Embodiment 1, during the cutting step 1002, the processing apparatus 1 uses the controller 100 to control the moving unit 40 to position one end of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200 held in the holding unit 10, in the Y-axis direction, and the cutting edge 25 of the first cutting blade 21-1, in a position aligned in the X-axis direction. The other end of the annular protrusion 211 of the wafer 200 held in the holding unit 10, in the Y-axis direction, and the cutting edge 25 of the second cutting blade 21-2, in a position aligned in the X-axis direction.

[0056] Furthermore, in Embodiment 1, during the cutting step 1002, the processing apparatus 1 controls the moving unit 40 via the controller 100 to position the lower end of the cutting edge 25 of the cutting blades 21-1 and 21-2 in the Z-axis direction at the center in the thickness direction of the protective tape 220 attached to the wafer 200 held by the holding unit 10. In Embodiment 1, during the cutting step 1002, the processing apparatus 1 controls the moving unit 40 via the controller 100 to move the holding unit 10 in the X-axis direction, bringing the wafer 200 held by the holding unit 10 closer to the cutting blades 21-1 and 21-2.

[0057] In Embodiment 1, in the cutting step 1002, the processing apparatus 1, without rotating the holding unit 10 around its axis using the rotary movement unit 44, cuts the cutting edge 25 of the first cutting blade 21-1 into one end in the Y-axis direction of the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 held in the holding unit 10, as shown in Figure 6, and cuts the cutting edge 25 of the second cutting blade 21-2 into the other end in the Y-axis direction of the annular protrusion 211 of the wafer 200 held in the holding unit 10, thereby cutting the cutting edges 25 of the cutting blades 21-1 and 21-2 to the center in the thickness direction of the protective tape 220.

[0058] Thus, in Embodiment 1, in the cutting step 1002, the first cutting blade 21-1 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction, and the second cutting blade 21-2 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction. In Embodiment 1, the first cutting blade 21-1 cuts into the boundary between the circular recess 210 and the annular protrusion 211 of the wafer held by the holding unit 10. The second cutting blade 21-2 cuts into the annular protrusion 211 of the wafer 200 held by the holding unit 10.

[0059] In addition, in the present invention, in the cutting step 1002 of Embodiment 1, the processing apparatus 1 may position the cutting edge 25 of the first cutting blade 21-1 above one end in the Y-axis direction of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200, and position the cutting edge 25 of the second cutting blade 21-2 above the other end in the Y-axis direction of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, and then lower the cutting blades 21-1 and 21-2 until the cutting edges 25 cut into the protective tape 220, thereby cutting into the wafer 200.

[0060] (Processing step) Figure 7 is a schematic front view showing a partial cross-section of the processing steps of the processing method shown in Figure 4. Figure 8 is a schematic top view showing the processing steps of the processing method shown in Figure 4. Note that Figure 8 omits the wafer 200 held in the holding unit 10.

[0061] The processing step 1003 involves moving the wafer 200 relative to the first cutting blade 21-1 and the second cutting blade 21-2 while the first cutting blade 21-1 is cutting into the boundary and the second cutting blade 21-2 is cutting into the annular protrusion 211, thereby performing annular processing on the boundary with the first cutting blade 21-1 and annular processing on the annular protrusion 211 with the second cutting blade 21-2.

[0062] In Embodiment 1, during the processing step 1003, the processing apparatus 1, with the controller 100 controlling the moving unit 40, rotates the holding unit 10 at least once around its axis, as shown in Figures 7 and 8, thereby moving the cutting blades 21-1, 21-2 and the wafer 200 held in the holding unit 10 relative to each other.

[0063] In Embodiment 1, in processing step 1003, the processing apparatus 1 cuts the outer edge 213 of the bottom surface 212 of the circular recess 210 with the first cutting blade 21-1, cutting the wafer 200 along the outer edge 213 of the bottom surface 212 of the circular recess 210. Cutting the wafer 200 along the outer edge 213 of the bottom surface 212 of the circular recess 210 corresponds to annular processing. Also in processing step 1003, the processing apparatus 1 cuts the annular protrusion 211 with the second cutting blade 21-2, removing the annular protrusion 211 from the wafer 200 along its entire circumference. Removing the annular protrusion 211 from the wafer 200 along its entire circumference corresponds to annular processing.

[0064] Thus, in Embodiment 1, the moving unit 40 moves the wafer 200 relative to the first cutting blade 21-1 and the second cutting blade 21-2 while the first cutting blade 21-1 is cutting into the boundary and the second cutting blade 21-2 is cutting into the annular protrusion 211. Also, in Embodiment 1, in processing step 1003, as shown in Figure 8, the rotational directions 211-1 and 211-2 at the upper ends of the cutting edges 25 of each cutting blade 21-1 and 21-2 are in the same direction as the rotational direction 101 around the axis of the holding unit 10.

[0065] In Embodiment 1, after the processing step 1003, the processing apparatus 1 controls the moving unit 40 via the controller 100 to raise the cutting units 20-1 and 20-2 to move them away from the holding unit 10, and also positions the holding unit 10 in the loading / unloading area, closes the on / off valve 12, and stops the suction holding of the wafer 200. In Embodiment 1, after the processing step 1003, the processing apparatus 1 controls the transport unit via the controller 100 to move the wafer 200 to the cleaning unit 51, cleans it in the cleaning unit 51, and then stores it in the cassette 6. The processing apparatus 1 applies the processing method shown in Figure 4 to each wafer 200 in the cassette 6 in sequence.

[0066] As described above, the processing apparatus 1 and processing method according to Embodiment 1 process the boundary between the circular recess 210 and the annular protrusion 211 with the first cutting blade 21-1, and process the annular protrusion 211 with the second cutting blade 21-2. In this way, the processing apparatus 1 and processing method according to Embodiment 1 can shorten the processing time because the processing is performed simultaneously with the first cutting blade 21-1 and the second cutting blade 21-2.

[0067] Furthermore, in the processing apparatus 1 and processing method according to Embodiment 1, the average abrasive particle size of the first cutting blade 21-1 is smaller than the average abrasive particle size of the second cutting blade 21-2. For this reason, in the processing apparatus 1 and processing method according to Embodiment 1, the area adjacent to the device of the circular recess 210 is processed with the first cutting blade 21-1 which has a fine abrasive particle size, thereby reducing the risk of crack formation and suppressing damage to the device 205.

[0068] As a result, the processing apparatus 1 and processing method according to Embodiment 1 have the effect of suppressing the occurrence of cracks when removing the annular protrusion 211 on the outer circumference of the wafer 200.

[0069] [Embodiment 2] The processing method according to Embodiment 2 will be described based on the drawings. Figure 9 is a flowchart showing the flow of the processing method according to Embodiment 2. Figure 10 is a schematic front view showing a partial cross-section of the holding step of the processing method shown in Figure 9. Figure 11 is a schematic front view showing a partial cross-section of the cutting step of the processing method shown in Figure 9. Figure 12 is a schematic front view showing a partial cross-section of the re-cutting and re-processing step of the processing method shown in Figure 9. Note that Figures 9, 10, 11, and 12 use the same reference numerals as Embodiment 1, and their descriptions are omitted.

[0070] The processing method according to Embodiment 2 is carried out by the processing apparatus 1 with the configuration described above, similar to Embodiment 1. That is, the processing method according to Embodiment 2 is also a processing operation of the processing apparatus 1 with the configuration described above. As shown in Figure 9, the processing method according to Embodiment 2 comprises a holding step 1001, a cutting step 1004, and a re-cutting and re-processing step 1005.

[0071] (Holding step) In Embodiment 2, during the holding step 1001, the processing apparatus 1 has a controller 100 that starts the rotation of the spindles 23 of each cutting unit 20-1, 20-2, i.e., the cutting blades 21-1, 21-2, and starts supplying cutting fluid to the cutting blades 21-1, 21-2. In Embodiment 2, during the holding step 1001, the processing apparatus 1 has a controller 100 that controls the cassette elevator 50 and the transport unit, etc., to remove one wafer 200 before processing from the cassette 6 and place the wafer 200 with its surface 201 side on the holding surface 11 of the holding unit 10 positioned in the loading / unloading area, via the protective tape 220.

[0072] In Embodiment 2, during the holding step 1001, the processing apparatus 1, via the controller 100, opens the on / off valve 12 and uses the protective tape 220 to suction-hold the surface 201 of the wafer 200 to the holding surface 11 of the holding unit 10 positioned in the loading / unloading area. In Embodiment 2, during the holding step 1001, the processing apparatus 1, via the controller 100, controls the moving unit 40 to position the holding unit 10 holding the wafer 200 in the processing area, causes the imaging unit 30 to image the wafer 200, and performs alignment based on the image acquired and the processing conditions.

[0073] In Embodiment 2, during the holding step 1001, as shown in Figure 10, the controller 100 controls the moving unit 40 to position the cutting edge 25 of the first cutting blade 21-1 above one end in the Y-axis direction of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200 held in the holding unit 10, and also positions the cutting edge 25 of the second cutting blade 21-2 above the other end in the Y-axis direction of the annular protrusion 211 of the wafer 200 held in the holding unit 10.

[0074] (Cutting step) The cutting step 1004 corresponds to the cutting step 1002 and the processing step 1003 described above. In other words, the cutting step 1004 is a step that performs the cutting step 1002 and the processing step 1003 simultaneously.

[0075] Furthermore, in Embodiment 1, during the cutting step 1004, the processing apparatus 1, with the controller 100 controlling the moving unit 40, lowers the cutting blades 21-1 and 21-2 in the Z-axis direction. As shown in Figure 10, with the cutting edges 25 of the cutting blades 21-1 and 21-2 positioned at the same height in the Z-axis direction, the cutting edge 25 of the first cutting blade 21-1 is made to cut into the outer edge 213 of the bottom surface 212 of the circular recess 210, and the cutting edge 25 of the second cutting blade 21-2 is made to cut into the annular protrusion 211, without reaching the protective tape 220. The distance in the Z-axis direction from the back surface 206 of the lower end of the cutting edge 25 of the second cutting blade 21-2 during the cutting step 1004 is determined by the processing conditions.

[0076] (Recutting and reworking step) The recutting and reprocessing step 1005 corresponds to a recutting step in which, after performing the cutting step 1004, which is the processing step 1003, the first cutting blade 21-1 cuts deeper into the boundary than in the cutting step 1004, and the second cutting blade 21-2 cuts deeper into the annular protrusion 211 than in the cutting step 1004. Furthermore, the recutting and reprocessing step 1005 corresponds to a reprocessing step in which, with the first cutting blade 21-1 cutting deeper into the boundary than in the cutting step 1004 and the second cutting blade 21-2 cutting deeper into the annular protrusion 211 than in the cutting step 1004, the wafer 200 is moved relative to the first cutting blade 21-1 and the second cutting blade 21-2, thereby performing annular processing on the boundary with the first cutting blade 21-1 and annular processing on the annular protrusion 211 with the second cutting blade 21-2.

[0077] In Embodiment 2, during the recutting and reprocessing step 1005, the processing apparatus 1, with the controller 100 controlling the movement unit 40 to rotate the holding unit 10 around its axis, lowers both the first cutting blade 21-1 and the second cutting blade 21-2 by a predetermined distance (the same distance for both the first cutting blade 21-1 and the second cutting blade 21-2) as shown in Figure 11. Thus, in Embodiment 2, during the recutting and reprocessing step 1005, the processing apparatus 1 cuts deeper into the boundary with the first cutting blade 21-1 than in the cutting step 1004, and cuts deeper into the annular protrusion 211 with the second cutting blade 21-2 than in the cutting step 1004. In this state, the cutting blades 21-1 and 21-2 and the wafer 200 held in the holding unit 10 are moved relative to each other around the axis of the holding unit 10.

[0078] In Embodiment 2, in the recutting and reprocessing step 1005, the processing apparatus 1 uses the first cutting blade 21-1 to cut the outer edge 213 of the bottom surface 212 of the circular recess 210 more deeply than in the cutting step 1004, over its entire circumference. Cutting the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 more deeply than in the cutting step 1004, over its entire circumference, corresponds to annular processing. Also in the recutting and reprocessing step 1005, the processing apparatus 1 uses the second cutting blade 21-2 to cut the annular protrusion 211 more deeply than in the cutting step 1004, over its entire circumference. Cutting the annular protrusion 211 of the wafer 200 more deeply than in the cutting step 1004, over its entire circumference, corresponds to annular processing.

[0079] In Embodiment 2, after the recutting and reprocessing step 1005, the processing apparatus 1 determines whether the controller 100 has cut the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 and removed the annular protrusion 211 (step 1006). In Embodiment 2, if the processing apparatus 1 determines that the controller 100 has not cut the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 and has not removed the annular protrusion 211 (step 1006: No), it returns to the recutting and reprocessing step 1005. In the return-to-re-cutting re-machining step 1005, the processing device 1, with the controller 100 controlling the moving unit 40 to rotate the holding unit 10 around its axis, lowers both the first cutting blade 21-1 and the Figure 2 cutting blade 21-2 by a predetermined distance determined by the processing conditions (the same distance for both the first cutting blade 21-1 and the second cutting blade 21-2).

[0080] In Embodiment 2, after the recutting and reprocessing step 1005, as shown in Figure 12, if the first cutting blade 21-1 cuts the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 and the second cutting blade 21-2 removes the annular protrusion 211, the processing apparatus 1 determines that the controller 100 has cut the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 and removed the annular protrusion 211 (step 1006: Yes). Subsequently, the processing apparatus 1 retracts the cutting units 20-1 and 20-2 from the holding unit 10, cleans the wafer 200 with the cleaning unit 51, and then stores it in the cassette 6.

[0081] Thus, in the machining method according to Embodiment 2, after the cutting step 1004 corresponding to machining step 1003, the re-cutting step and the re-machining step are repeated at least once each, that is, the re-cutting and re-machining step 1005 is repeated at least once, thereby cutting the boundary portion with the first cutting blade 21-1 and cutting and removing the annular protrusion 211 with the second cutting blade 21-2.

[0082] The processing apparatus 1 and processing method according to Embodiment 2 process the boundary between the circular recess 210 and the annular protrusion 211 with the first cutting blade 21-1 and process the annular protrusion 211 with the second cutting blade 21-2. Similar to Embodiment 1, this method has the effect of shortening processing time and suppressing the occurrence of cracks when removing the annular protrusion 211 on the outer circumference of the wafer 200.

[0083] [Embodiment 3] The processing apparatus and processing method according to Embodiment 3 will be described based on the drawings. Figure 13 is a schematic front view showing a partial cross-section of the cutting step of the processing method according to Embodiment 3. Figure 14 is a schematic front view showing a partial cross-section of the processing step of the processing method according to Embodiment 3. Note that Figures 13 and 14 use the same reference numerals as Embodiment 1 for the same parts and their descriptions are omitted.

[0084] In the processing apparatus 1 according to Embodiment 3, the thickness of the cutting edge 25 of the first cutting blade 21-1 is equal to the thickness of the cutting edge 25 of the second cutting blade 21-2, and the thickness of the cutting edges 25 of these cutting blades 21-1 and 21-2 is equivalent to the thickness of the cutting edge 25 of the first cutting blade 21-1 in Embodiments 1 and 2. In this invention, the cutting edge 25 of the second cutting blade 21-2 may be thinner than the cutting edge 25 of the first cutting blade 21-1. In this case, a cutting blade with a thinner cutting edge 25 reduces the cutting load during cutting, thus suppressing the occurrence of chipping. By cutting the boundary between the device region 202 and the outer peripheral excess region 203 with the cutting edge 25 of the second cutting blade 21-2, which is thinner than the cutting edge 25 of the first cutting blade 21-1, the occurrence of chipping and cracks in the boundary region can be prevented, and damage to the device region 202 can be prevented.

[0085] The processing method according to Embodiment 3 is carried out by the processing apparatus 1 having the configuration described above, similar to Embodiment 1. That is, the processing method according to Embodiment 3 is also a processing operation of the processing apparatus 1 having the configuration described above. The processing method according to Embodiment 3 comprises a holding step 1001, a cutting step 1002, and a processing step 1003, similar to Embodiment 1.

[0086] (Holding step) In Embodiment 3, during the holding step 1001, the processing apparatus 1 holds the wafer 200 on the holding surface 11 of the holding unit 10 by suction, via the protective tape 220, on the surface 201 side of the wafer 200, similar to Embodiment 1.

[0087] (Cutting step) In Embodiment 3, during the cutting step 1002, the processing apparatus 1 has the controller 100 cause the imaging unit 30 to image the wafer 200, similar to Embodiment 1, to perform alignment. In Embodiment 3, during the cutting step 1002, the processing apparatus 1 has the controller 100 control the moving unit 40 to position one end of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200 held in the holding unit 10, in the Y-axis direction, and the cutting edge 25 of the first cutting blade 21-1, in a position aligned in the X-axis direction. At the same time, the other end of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, in the Y-axis direction, and the cutting edge 25 of the second cutting blade 21-2, in a position aligned in the X-axis direction.

[0088] Furthermore, in Embodiment 3, during the cutting step 1002, the processing apparatus 1 controls the movement unit 40 via the controller 100 to position the lower end of the cutting edge 25 of the cutting blades 21-1 and 21-2 in the Z-axis direction at the center in the thickness direction of the protective tape 220 attached to the wafer 200 held by the holding unit 10.

[0089] In Embodiment 3, in the cutting step 1002, the processing apparatus 1, without rotating the holding unit 10 around its axis using the rotary movement unit 44, cuts the cutting edge 25 of the first cutting blade 21-1 into one end in the Y-axis direction of the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 held in the holding unit 10, as shown in Figure 13, and cuts the cutting edge 25 of the second cutting blade 21-2 into the other end in the Y-axis direction of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, thereby cutting the cutting edges 25 of the cutting blades 21-1 and 21-2 to the center in the thickness direction of the protective tape 220.

[0090] Thus, in Embodiment 3, in the cutting step 1002, the first cutting blade 21-1 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction, and the second cutting blade 21-2 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction.

[0091] In addition, in the present invention, in the cutting step 1002 of Embodiment 3, the processing apparatus 1 may position the cutting edge 25 of the first cutting blade 21-1 above one end in the Y-axis direction of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200, and position the cutting edge 25 of the second cutting blade 21-2 above the other end in the Y-axis direction of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, and then lower the cutting blades 21-1 and 21-2 until the cutting edges 25 cut into the protective tape 220, thereby cutting into the wafer 200. Furthermore, in the present invention, in the cutting step 1002 of Embodiment 3, the processing apparatus 1 may cause the cutting edges 25 of the first cutting blade 21-1 and the second cutting blade 21-2 to cut while rotating the holding unit 10 around its axis.

[0092] (Processing step) In Embodiment 3, during the processing step 1003, the processing apparatus 1, with the controller 100 controlling the moving unit 40, rotates the holding unit 10 around its axis using the moving unit 40, as shown in Figure 14, while moving the first cutting blade 21-1 toward the outer edge 213 of the wafer 200 held in the holding unit 10, and moving the second cutting blade 21-2 toward the center of the wafer 200 held in the holding unit 10.

[0093] In Embodiment 3, in processing step 1003, the processing apparatus 1 cuts the outer edge 213 of the bottom surface 212 of the circular recess 210 with the first cutting blade 21-1, cutting the wafer 200 all around the outer edge of the bottom surface 212 of the circular recess 210, and cuts the annular protrusion 211 with the second cutting blade 21-2, removing the annular protrusion 211 of the wafer 200 all around. After that, the processing apparatus 1 retracts the cutting units 20-1 and 20-2 from the holding unit 10, cleans the wafer 200 with the cleaning unit 51, and then stores it in the cassette 6.

[0094] Thus, in Embodiment 3, in processing step 1003, the holding unit 10 is rotated around its axis while the cutting blades 21-1 and 21-2 that have cut into the wafer 200 are moved in the Y-axis direction, thereby cutting the wafer 200 in a spiral pattern with the cutting blades 21-1 and 21-2. In Embodiment 3, cutting the wafer 200 in a spiral pattern with the cutting blades 21-1 and 21-2 is equivalent to performing annular processing on the wafer 200 with the cutting blades 21-1 and 21-2.

[0095] The processing apparatus 1 and processing method according to Embodiment 3 process the boundary between the circular recess 210 and the annular protrusion 211 with the first cutting blade 21-1, and process the annular protrusion 211 with the second cutting blade 21-2. Similar to Embodiment 1, this method has the effect of shortening processing time and suppressing the occurrence of cracks when removing the annular protrusion 211 on the outer circumference of the wafer 200.

[0096] [Variation] A processing apparatus and processing method relating to a modified example of Embodiment 3 will be described based on the drawings. Figure 15 is a flowchart showing the flow of the processing method relating to a modified example of Embodiment 3. Note that in Figure 15, the same reference numerals are used for the same parts as in Embodiment 1, and their descriptions are omitted.

[0097] In the modified version of Embodiment 3, the processing apparatus 1 is similar to Embodiment 3 in that the thickness of the cutting edge 25 of the first cutting blade 21-1 is equal to the thickness of the cutting edge 25 of the second cutting blade 21-2, and the thickness of the cutting edges 25 of these cutting blades 21-1 and 21-2 is equivalent to the thickness of the cutting edge 25 of the first cutting blade 21-1 in Embodiments 1 and 2.

[0098] The processing method according to the modified embodiment of Embodiment 3 is carried out by the processing apparatus 1 having the configuration described above, similar to Embodiment 1 and the like. That is, the processing method according to Embodiment 3 is also a processing operation of the processing apparatus 1 having the configuration described above. As shown in Figure 15, the processing method according to the modified embodiment of Embodiment 3 comprises a holding step 1001, a cutting step 1002, a processing step 1003, a re-cutting step 1007, and a re-processing step 1008.

[0099] (Holding step) In a modified example of Embodiment 3, in the holding step 1001, the processing apparatus 1 holds the wafer 200 on the holding surface 11 of the holding unit 10 by suction via the protective tape 220, similar to Embodiments 1 and 3.

[0100] (Cutting step) In a modified example of Embodiment 3, in the cutting step 1002, the processing apparatus 1, similar to Embodiment 3, positions one end of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200 held in the holding unit 10, in the Y-axis direction, and the cutting edge 25 of the first cutting blade 21-1, in a position aligned in the X-axis direction. It also positions the other end of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, in the Y-axis direction, and the cutting edge 25 of the second cutting blade 21-2, in a position aligned in the X-axis direction.

[0101] Furthermore, in a modified example of Embodiment 3, in the cutting step 1002, the processing apparatus 1, similar to Embodiment 3, positions the Z-axis position of the lower end of the cutting edge 25 of the cutting blades 21-1 and 21-2 at the center in the thickness direction of the protective tape 220 attached to the wafer 200 held by the holding unit 10, and moves the holding unit 10 in the X-axis direction to bring the wafer 200 held by the holding unit 10 closer to the cutting blades 21-1 and 21-2.

[0102] In a modified example of Embodiment 3, in the cutting step 1002, the processing apparatus 1, similar to Embodiment 3, does not rotate the holding unit 10 around its axis using the rotary moving unit 44, but instead cuts the cutting edge 25 of the first cutting blade 21-1 into one end in the Y-axis direction of the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 held in the holding unit 10, and also cuts the cutting edge 25 of the second cutting blade 21-2 into the other end in the Y-axis direction of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, thereby cutting the cutting edges 25 of the cutting blades 21-1 and 21-2 to the center in the thickness direction of the protective tape 220.

[0103] Thus, in the modified embodiment of the third embodiment, in the cutting step 1002, the first cutting blade 21-1 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction, and the second cutting blade 21-2 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction.

[0104] In addition, in the modified version of Embodiment 3, in the cutting step 1002, similar to Embodiment 3, the processing apparatus 1 may position the cutting edge 25 of the first cutting blade 21-1 above one end in the Y-axis direction of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200, and position the cutting edge 25 of the second cutting blade 21-2 above the other end in the Y-axis direction of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, and then lower the cutting blades 21-1 and 21-2 until the cutting edges 25 cut into the protective tape 220, thereby cutting into the wafer 200.

[0105] (Processing step) In a modified example of Embodiment 3, in processing step 1003, the processing apparatus 1, with the controller 100 controlling the moving unit 40, rotates the holding unit 10 at least once around its axis by the moving unit 40 without moving the cutting units 20-1 and 20-2 in the Y-axis direction, and cuts the outer edge 213 of the bottom surface 212 of the circular recess 210 with the first cutting blade 21-1, cutting the wafer 200 all around the outer edge of the bottom surface 212 of the circular recess 210, and cuts the annular protrusion 211 all around with the second cutting blade 21-2.

[0106] (Re-cutting step) In a modified example of Embodiment 3, the re-cutting step 1007 is a step in which, after performing the processing step 1003, the first cutting blade 21-1 is made to cut the wafer 200 in the radial direction at a position different from that of the cutting step 1002, and the second cutting blade 21-2 is made to cut the wafer 200 in the radial direction at a position different from that of the cutting step 1002.

[0107] In a modified example of Embodiment 3, in the re-cutting step 1007, the processing apparatus 1 controls the moving unit 40 with the controller 100 to position the lower end of the cutting edge 25 at the same height as in the cutting step 1002, positioning the cutting edge 25 of the first cutting blade 21-1 a predetermined distance shorter than the thickness of the cutting edge 25 on the outer circumference of the wafer 200 than in the cutting step 1002, and positioning the cutting edge 25 of the second cutting blade 21-1 a predetermined distance shorter than the thickness of the cutting edge 25 on the inner circumference of the wafer 200 than in the cutting step 1002, and then moves the holding unit 10 in the X-axis direction to cut the wafer 200 with the cutting blades 21-1 and 21-2.

[0108] In addition, in the modified embodiment of the present invention, in the re-cutting step 1007, similar to the cutting step 1002, the processing apparatus 1 may position the cutting edges 25 of the cutting blades 21-1 and 21-2 above the wafer 200, and then lower the cutting blades 21-1 and 21-2 until the cutting edges 25 cut into the protective tape 220, thereby causing the cutting blades 21-1 and 21-2 to cut into the wafer 200.

[0109] (Reprocessing step) In a modified example of Embodiment 3, the reworking step 1008 is a step in which, with the first cutting blade 21-1 cutting at a position different from that of the cutting step 1002 in the radial direction of the wafer 200 and the second cutting blade 21-2 cutting at a position different from that of the cutting step 1002 in the radial direction of the wafer 200, the wafer 200 is moved relative to the first cutting blade 21-1 and the second cutting blade 21-2, thereby performing annular processing on the boundary portion with the first cutting blade 21-1 and annular processing on the annular protrusion 211 with the second cutting blade 21-2.

[0110] In a modified example of Embodiment 3, in the reworking step 1008, the processing apparatus 1, with the controller 100 controlling the moving unit 40, rotates the holding unit 10 at least once around its axis without moving the cutting units 20-1 and 20-2 in the Y-axis direction, thereby rotating the wafer 200 relative to the first cutting blade 21-1 and the second cutting blade 21-2 around the axis of the holding unit 10. The first cutting blade 21-1 cuts the outer edge 213 of the bottom surface 212 of the circular recess 210, cutting the wafer 200 all the way around the outer edge of the bottom surface 212 of the circular recess 210, and the second cutting blade 21-2 cuts the annular protrusion 211 all the way around.

[0111] Thus, in the modified embodiment of the third embodiment, in the reworking step 1008, the processing apparatus 1 performs annular processing on the wafer 200 with cutting blades 21-1 and 21-2.

[0112] In a modified example of Embodiment 3, after the reworking step 1008, the processing apparatus 1 determines whether the controller 100 has removed the annular protrusion 211 of the wafer 200 (step 1009). In a modified example of Embodiment 3, if the processing apparatus 1 determines that the controller 100 has not removed the annular protrusion 211 (step 1009: No), it returns to the recutting step 1007. In the return re-cutting step 1007, the processing apparatus 1, with the controller 100 controlling the moving unit 40, positions the lower end of the cutting edge 25 at the same height as in the cutting step 1002, positions the cutting edge 25 of the first cutting blade 21-1 at a predetermined distance shorter than the thickness of the cutting edge 25 on the outer circumference of the wafer 200 than in the most recent re-cutting step 1007, and positions the cutting edge 25 of the second cutting blade 21-1 at a predetermined distance shorter than the thickness of the cutting edge 25 on the inner circumference of the wafer 200 than in the most recent re-cutting step 1007, and then moves the holding unit 10 in the X-axis direction to cut the wafer 200 with the cutting blades 21-1 and 21-2.

[0113] In a modified example of Embodiment 3, after the reworking step 1008, when the controller 100 determines that the annular protrusion 211 has been removed (step 1009: Yes), the processing apparatus 1 retracts the cutting units 20-1 and 20-2 from the holding unit 10, cleans the wafer 200 with the cleaning unit 51, and then stores it in the cassette 6.

[0114] Thus, in the modified version of Embodiment 3, after the machining step 1003, the re-cutting step 1007 and the re-machining step 1008 are repeated one or more times each, thereby separating the circular recess 210 from the annular protrusion 211 with the first cutting blade 21-1 and removing the annular protrusion 211 with the second cutting blade 21-2.

[0115] The processing apparatus 1 and processing method according to the modified embodiment 3 process the boundary between the circular recess 210 and the annular protrusion 211 with the first cutting blade 21-1 and process the annular protrusion 211 with the second cutting blade 21-2. Similar to embodiment 1, this reduces processing time and suppresses the occurrence of cracks when removing the annular protrusion 211 on the outer circumference of the wafer 200.

[0116] [Embodiment 4] The processing apparatus and processing method according to Embodiment 4 will be described based on the drawings. Figure 16 is a perspective view showing an example of the configuration of the processing apparatus according to Embodiment 4. Figure 17 is a flowchart showing the flow of the processing method according to Embodiment 4. Figure 18 is a schematic front view showing a partial cross-section of the holding step of the processing method shown in Figure 17. Figure 19 is an enlarged cross-sectional view showing part XVIII in Figure 18. Figure 20 is a schematic front view showing a partial cross-section of the processing step of the processing method shown in Figure 17. Figure 21 is a schematic cross-sectional view showing the trajectory of the cutting edge of the cutting blade during the processing step of the processing method shown in Figure 17. Figure 22 is a schematic cross-sectional view showing the residual part detection step of the processing method shown in Figure 17. Figure 23 is a schematic cross-sectional view showing the state at which the processing step of the processing method shown in Figure 17 is completed. Note that Figures 16, 17, 18, 19, 20, 21, 22, and 23 use the same reference numerals as Embodiment 1, etc., and their descriptions are omitted.

[0117] As shown in Figure 16, the processing apparatus 1 according to Embodiment 4 has multiple clamping portions 15 provided around the holding unit 10.

[0118] In the processing apparatus 1 according to Embodiment 4, the thickness of the cutting edge 25 of the first cutting blade 21-1 is equal to the thickness of the cutting edge 25 of the second cutting blade 21-2, and the thickness of the cutting edges 25 of these cutting blades 21-1 and 21-2 is equivalent to the thickness of the cutting edge 25 of the first cutting blade 21-1 in Embodiments 1 and 2.

[0119] Furthermore, in the processing apparatus 1 according to Embodiment 4, the outer diameter of the holding unit 10 is formed to be smaller than the inner diameter of the circular recess 210 of the wafer 200.

[0120] The processing method according to Embodiment 4 is carried out by the processing apparatus 1 with the configuration described above, similar to Embodiment 1. That is, the processing method according to Embodiment 4 is also a processing operation of the processing apparatus 1 with the configuration described above. As shown in Figure 17, the processing method according to Embodiment 4 comprises a holding step 1001, a cutting step 1002, a processing step 1003, and a remaining portion detection step 1010.

[0121] In the processing method according to Embodiment 4, as shown in Figure 18, the center of a disc-shaped tape 221, which has a larger diameter than the wafer 200, is attached to the bottom surface 212 of the circular recess 210, and an annular frame 222, whose inner diameter is larger than the outer diameter of the wafer 200, is attached to the outer edge of the tape 221, and the wafer 200 is supported by the annular frame 222 via the tape 221. Thus, in Embodiment 4, the tape 221 is arranged on the back surface 206 side of the wafer 200. The annular frame 222 is clamped by the clamp portion 15.

[0122] (Holding step) In Embodiment 4, during the holding step 1001, as shown in Figure 18, the processing apparatus 1 holds the bottom surface 212 of the circular recess 210 on the back surface 206 of the wafer 200 by suction via the tape 221 to the holding surface 11 of the holding unit 10, and clamps the annular frame 222 with the clamping part 15. Since the circular recess 210 of the wafer 200 consists of the first recess 210-1 and the second recess 210-2 described above, a step portion 210-3 is formed between them. As shown in Figure 19, the tape 221 is not attached to the step portion 210-3, and a gap 223 is formed between the tape 221 and the inner circumferential wall of the circular recess 210.

[0123] (Cutting step) In Embodiment 4, during the cutting step 1002, the processing apparatus 1 has the controller 100 cause the imaging unit 30 to image the wafer 200, similar to Embodiment 1, and perform alignment. In Embodiment 4, during the cutting step 1002, the processing apparatus 1 has the controller 100 control the moving unit 40 to position one end of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200 held in the holding unit 10, in the Y-axis direction, and the cutting edge 25 of the first cutting blade 21-1, in a position aligned in the X-axis direction. At the same time, the other end of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, in the Y-axis direction, and the cutting edge 25 of the second cutting blade 21-2, in a position aligned in the X-axis direction.

[0124] Furthermore, in Embodiment 4, during the cutting step 1002, the processing apparatus 1 controls the moving unit 40 via the controller 100 to position the lower end of the cutting edge 25 of the cutting blades 21-1 and 21-2 in the Z-axis direction at the center in the thickness direction of the tape 221 attached to the wafer 200 held by the holding unit 10.

[0125] In Embodiment 4, during the cutting step 1002, the processing apparatus 1, without rotating the holding unit 10 around its axis using the rotary movement unit 44, causes the cutting edge 25 of the first cutting blade 21-1 to cut into one end in the Y-axis direction of the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 held in the holding unit 10, and the cutting edge 25 of the second cutting blade 21-2 to cut into the other end in the Y-axis direction of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, thereby cutting the cutting edges 25 of the cutting blades 21-1 and 21-2 to the center in the thickness direction of the tape 221.

[0126] Thus, in Embodiment 4, in the cutting step 1002, the first cutting blade 21-1 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction, and the second cutting blade 21-2 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction, and the first cutting blade 21-1 and the second cutting blade 21-2 are made to cut into the wafer 200 to a depth from the surface 201 to the tape 221.

[0127] In addition, in the cutting step 1002 of Embodiment 4, the processing apparatus 1 may position the cutting edge 25 of the first cutting blade 21-1 above one end in the Y-axis direction of the outer edge 213 of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200, and position the cutting edge 25 of the second cutting blade 21-2 above the other end in the Y-axis direction of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, and then lower the cutting blades 21-1 and 21-2 until the cutting edges 25 cut into the tape 221, thereby cutting into the wafer 200.

[0128] (Processing step) In Embodiment 4, during the processing step 1003, the processing apparatus 1, with the controller 100 controlling the moving unit 40, rotates the holding unit 10 around its axis using the moving unit 40, as shown in Figure 20, while moving the first cutting blade 21-1 toward the outer edge 213 of the wafer 200 held in the holding unit 10, and moving the second cutting blade 21-2 toward the center of the wafer 200 held in the holding unit 10.

[0129] In Embodiment 4, in processing step 1003, as shown in Figure 21, the processing apparatus 1 moves the cutting edge 25 of the first cutting blade 21-1 gradually towards the outer circumference of the wafer 200 while the cutting edge 25 of the second cutting blade 21-2 gradually moves towards the inner circumference of the wafer 200, thereby cutting the outer edge 213 of the bottom surface 212 of the circular recess 210 with the first cutting blade 21-1 and cutting the annular protrusion 211 with the second cutting blade 21-2.

[0130] (Remaining part detection step) The residual portion detection step 1010 is a step in which the annular protrusion 211 is imaged by the imaging unit 30 or an imaging unit 60 separate from the imaging unit 30 during the processing step 1003, and the residual portion of the annular protrusion 211 in the radial direction of the wafer 200 is detected. In Embodiment 4, the residual portion detection step 1010 is performed during the processing step 1003. In Embodiment 4, the residual portion detection step 1010 is also a step in which the tape 221, which has a gap 223 between it and the inner circumferential side wall of the circular recess 210, is cut by the second cutting blade 21-2, thereby preventing the formation of a hole in the tape 221.

[0131] In Embodiment 4, during the remaining portion detection step 1010, the processing apparatus 1, as shown in Figure 22, has the controller 100 position the imaging unit 30 or imaging unit 60 above the annular protrusion 211, and the imaging unit 30 or imaging unit 60 images the annular protrusion 211. In Embodiment 4, during the remaining portion detection step 1010, the processing apparatus 1, as shown in Figure 22, has the controller 100 detect the thickness of the remaining portion of the annular protrusion 211.

[0132] In Embodiment 4, during the residual portion detection step 1010, the processing device 1 terminates the processing step 1003 when the controller 100 detects that all of the circular recess 210 has been removed, as shown in Figure 23.

[0133] Furthermore, in the present invention, in the residual portion detection step 1010, the controller 100 estimates the number of rotations of the holding unit 10 until the circular recess 210 is removed from the image obtained by the imaging unit 30 or imaging unit 60, and the processing step 1003 may be terminated once the holding unit 10 has rotated for the estimated number of rotations.

[0134] Thus, in Embodiment 4, in processing step 1003, as shown in Figure 21, the processing apparatus 1 cuts the outer edge 213 of the bottom surface 212 of the circular recess 210 with the first cutting blade 21-1, cutting the wafer 200 along the outer edge of the bottom surface 212 of the circular recess 210, and simultaneously cuts the annular protrusion 211 with the second cutting blade 21-2, removing the annular protrusion 211 of the wafer 200 along its entire circumference. After that, similar to Embodiment 1, the processing apparatus 1 retracts the cutting units 20-1 and 20-2 from the holding unit 10, cleans the wafer 200 with the cleaning unit 51, and then stores it in the cassette 6.

[0135] Thus, in Embodiment 4, in processing step 1003, the holding unit 10 is rotated around its axis while the cutting blades 21-1 and 21-2 that have cut into the wafer 200 are moved in the Y-axis direction, thereby cutting the wafer 200 in a spiral pattern with the cutting blades 21-1 and 21-2. In Embodiment 3, cutting the wafer 200 in a spiral pattern with the cutting blades 21-1 and 21-2 is equivalent to performing annular processing on the wafer 200 with the cutting blades 21-1 and 21-2.

[0136] The processing apparatus 1 and processing method according to Embodiment 4 process the boundary between the circular recess 210 and the annular protrusion 211 with the first cutting blade 21-1 and process the annular protrusion 211 with the second cutting blade 21-2. Similar to Embodiment 1, this method has the effect of shortening processing time and suppressing the occurrence of cracks when removing the annular protrusion 211 on the outer circumference of the wafer 200.

[0137] In the processing apparatus 1 and processing method according to Embodiment 4, the processing step 1003 is performed while detecting the remaining portion of the annular protrusion 211 in the remaining portion detection step 1010, so that the tape 221 is processed by the second cutting blade 21-2 and the holes in the tape 221 are suppressed.

[0138] Furthermore, in Embodiment 4, the residual portion detection step 1010 may be performed by temporarily suspending the processing step 1003, in which case the processing step 1003 is resumed after the residual portion detection step 1010.

[0139] [Variation] A processing apparatus and processing method relating to a modified example of Embodiment 4 will be described based on the drawings. Figure 24 is a flowchart showing the flow of the processing method relating to a modified example of Embodiment 4. Note that in Figure 24, the same reference numerals are used for the same parts as in Embodiment 1, etc., and their descriptions are omitted.

[0140] The processing apparatus 1 according to a modification of Embodiment 4 has multiple clamping portions 15 provided around the holding unit 10, similar to Embodiment 4.

[0141] In the modified version of Embodiment 4, the processing apparatus 1 is similar to Embodiment 4 in that the thickness of the cutting edge 25 of the first cutting blade 21-1 is equal to the thickness of the cutting edge 25 of the second cutting blade 21-2, and the thickness of the cutting edges 25 of these cutting blades 21-1 and 21-2 is equivalent to the thickness of the cutting edge 25 of the first cutting blade 21-1 in Embodiments 1 and 2.

[0142] Furthermore, in the modified version of Embodiment 4, the processing apparatus 1 is formed such that the outer diameter of the holding unit 10 is smaller than the inner diameter of the circular recess 210 of the wafer 200, similar to Embodiment 4.

[0143] The processing method according to the modified embodiment of Embodiment 4 is carried out by the processing apparatus 1 with the configuration described above, similar to Embodiment 1 and the like. That is, the processing method according to Embodiment 4 is also a processing operation of the processing apparatus 1 with the configuration described above. As shown in Figure 24, the processing method according to the modified embodiment of Embodiment 4 comprises a holding step 1001, a cutting step 1002, a processing step 1003, a remaining portion detection step 1010, a re-cutting step 1007, and a re-processing step 1008.

[0144] (Holding step) In a modified example of Embodiment 4, in the holding step 1001, the processing apparatus 1, similar to Embodiment 4, suction-holds the back surface 206 side of the wafer 200, i.e., the bottom surface 212 of the circular recess 210, to the holding surface 11 of the holding unit 10 via the tape 221, and clamps the annular frame 222 with the clamping portion 15.

[0145] (Cutting step) In a modified example of Embodiment 4, in the cutting step 1002, the processing apparatus 1, similar to Embodiment 4, positions one end of the outer edge 213 in the Y-axis direction of the flat bottom surface 212 of the circular recess 210, which is the boundary between the circular recess 210 and the annular protrusion 211 of the wafer 200 held in the holding unit 10, and the cutting edge 25 of the first cutting blade 21-1 in a position aligned in the X-axis direction, and also positions the other end of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10 in the Y-axis direction and the cutting edge 25 of the second cutting blade 21-2 in a position aligned in the X-axis direction.

[0146] Furthermore, in a modified example of Embodiment 4, in the cutting step 1002, the processing apparatus 1, similar to Embodiment 4, positions the Z-axis position of the lower end of the cutting edge 25 of the cutting blades 21-1 and 21-2 at the center in the thickness direction of the tape 221 attached to the wafer 200 held by the holding unit 10, and moves the holding unit 10 in the X-axis direction to bring the wafer 200 held by the holding unit 10 closer to the cutting blades 21-1 and 21-2.

[0147] In a modified example of Embodiment 4, in the cutting step 1002, the processing apparatus 1, similar to Embodiment 4, does not rotate the holding unit 10 around its axis using the rotary movement unit 44, but instead cuts the cutting edge 25 of the first cutting blade 21-1 into one end in the Y-axis direction of the outer edge 213 of the bottom surface 212 of the circular recess 210 of the wafer 200 held in the holding unit 10, and also cuts the cutting edge 25 of the second cutting blade 21-2 into the other end in the Y-axis direction of the outer edge of the annular protrusion 211 of the wafer 200 held in the holding unit 10, thereby cutting the cutting edges 25 of the cutting blades 21-1 and 21-2 to the center in the thickness direction of the protective tape 220.

[0148] Thus, in the modified embodiment of Embodiment 4, in the cutting step 1002, the first cutting blade 21-1 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction, and the second cutting blade 21-2 is made to cut into the wafer 200 to a depth that completely cuts the wafer 200 in the thickness direction.

[0149] (Processing step) In Embodiment 4, in processing step 1003, the processing apparatus 1, with the controller 100 controlling the moving unit 40, rotates the holding unit 10 at least once around its axis by the moving unit 40 without moving the cutting units 20-1 and 20-2 in the Y-axis direction, and cuts the outer edge 213 of the bottom surface 212 of the circular recess 210 with the first cutting blade 21-1, cutting the wafer 200 all around at the outer edge of the bottom surface 212 of the circular recess 210, and cutting the annular protrusion 211 all around with the second cutting blade 21-2. Thus, in this modified embodiment of Embodiment 4, in processing step 1003, the processing apparatus 1 performs annular processing on the wafer 200 with the cutting blades 21-1 and 21-2.

[0150] (Remaining part detection step) In a modified example of Embodiment 4, the residual portion detection step 1010 is a step in which, after performing the processing step 1003, the annular protrusion 211 is imaged and the residual portion of the annular protrusion 211 in the radial direction of the wafer 200 is detected. In a modified example of Embodiment 4, the residual portion detection step 1010 is also a step in which the tape 221, which has a gap 223 between it and the inner circumferential side wall of the circular recess 210, is cut by the second cutting blade 21-2 and a hole is formed in the tape 221.

[0151] In a modified example of Embodiment 4, in the residual portion detection step 1010, the processing apparatus 1 has the controller 100 position the imaging unit 30 or imaging unit 60 above the annular protrusion 211, and the imaging unit 30 or imaging unit 60 images the annular protrusion 211. In a modified example of Embodiment 4, in the residual portion detection step 1010, the processing apparatus 1 has the controller 100 detect the thickness of the residual portion of the annular protrusion 211.

[0152] Subsequently, in the modified embodiment of Embodiment 4, the processing apparatus 1 determines whether or not the annular protrusion 211 has been removed based on the image captured by the imaging unit 30 or imaging unit 60 using the controller 100 (step 1009). In the modified embodiment of Embodiment 4, if the processing apparatus 1 determines that the annular protrusion 211 has not been removed based on the image captured by the imaging unit 30 or imaging unit 60 using the controller 100 (step 1009: No), it proceeds to the re-cutting step 1007.

[0153] (Re-cutting step) In a modified example of Embodiment 4, the re-cutting step 1007 is a step in which, after performing the processing step 1003, the first cutting blade 21-1 is made to cut the wafer 200 in the radial direction at a position different from that of the cutting step 1002, and the second cutting blade 21-2 is made to cut the wafer 200 in the radial direction at a position different from that of the cutting step 1002.

[0154] In a modified example of Embodiment 4, in the re-cutting step 1007, the processing apparatus 1, with the controller 100 controlling the moving unit 40, positions the lower end of the cutting edge 25 at the same height as in the cutting step 1002, positions the cutting edge 25 of the first cutting blade 21-1 a predetermined distance shorter than the thickness of the cutting edge 25 on the outer circumference of the wafer 200 than in the cutting step 1002, positions the cutting edge 25 of the second cutting blade 21-1 a predetermined distance shorter than the thickness of the cutting edge 25 on the inner circumference of the wafer 200 than in the cutting step 1002, and then moves the holding unit 10 in the X-axis direction to cut the wafer 200 with the cutting blades 21-1 and 21-2.

[0155] In addition, in the modified embodiment of the present invention, in the cutting step 1002 and the re-cutting step 1007, the processing apparatus 1 may first position the cutting edges 25 of the cutting blades 21-1 and 21-2 above the wafer 200, and then lower the cutting blades 21-1 and 21-2 until the cutting edges 25 cut into the tape 221, thereby causing the cutting blades 21-1 and 21-2 to cut into the wafer 200.

[0156] (Reprocessing step) In a modified example of Embodiment 4, the reworking step 1008 is a step in which, with the first cutting blade 21-1 cutting at a position different from that of the cutting step 1002 in the radial direction of the wafer 200 and the second cutting blade 21-2 cutting at a position different from that of the cutting step 1002 in the radial direction of the wafer 200, the wafer 200 is moved relative to the first cutting blade 21-1 and the second cutting blade 21-2, thereby performing annular processing on the boundary portion with the first cutting blade 21-1 and annular processing on the annular protrusion 211 with the second cutting blade 21-2.

[0157] In a modified example of Embodiment 4, in the reworking step 1008, the processing apparatus 1, with the controller 100 controlling the moving unit 40, rotates the holding unit 10 at least once around its axis without moving the cutting units 20-1 and 20-2 in the Y-axis direction. This causes the wafer 200 to rotate relative to the first cutting blade 21-1 and the second cutting blade 21-2 around the axis of the holding unit 10, thereby cutting the outer edge 213 of the bottom surface 212 of the circular recess 210 with the first cutting blade 21-1, cutting the wafer 200 all the way around the outer edge of the bottom surface 212 of the circular recess 210, and cutting the annular protrusion 211 all the way around with the second cutting blade 21-2. Thus, in a modified example of Embodiment 4, in the reworking step 1008, the processing apparatus 1 performs annular processing on the wafer 200 with the cutting blades 21-1 and 21-2.

[0158] In a modified example of Embodiment 4, after the reworking step 1008, the processing apparatus 1 returns to the residual portion detection step 1010. In a modified example of Embodiment 4, after returning to the residual portion detection step 1010, if it is determined that the annular protrusion 211 of the wafer 200 has not been removed (step 1009: No), the recutting step 1007 and the reworking step 1008 are performed again.

[0159] In the re-cutting step 1007, the controller 100 controls the moving unit 40 to position the lower end of the cutting edge 25 at the same height as in the cutting step 1002, positioning the cutting edge 25 of the first cutting blade 21-1 a predetermined distance shorter than the thickness of the cutting edge 25 on the outer circumference of the wafer 200 than in the most recent re-cutting step 1007, and positioning the cutting edge 25 of the second cutting blade 21-1 a predetermined distance shorter than the thickness of the cutting edge 25 on the inner circumference of the wafer 200 than in the most recent re-cutting step 1007, before moving the holding unit 10 in the X-axis direction to cut the wafer 200 with the cutting blades 21-1 and 21-2. In the re-processing step 1008, the controller 100 controls the processing device 1 to perform annular processing on the wafer 200 with the cutting blades 21-1 and 21-2, similar to the first re-processing step 1008.

[0160] In a modified example of Embodiment 4, after the residual portion detection step 1010, if the controller 100 determines that the annular protrusion 211 has been removed (step 1009: Yes), the processing apparatus 1 retracts the cutting units 20-1 and 20-2 from the holding unit 10, cleans the wafer 200 with the cleaning unit 51, and then stores it in the cassette 6.

[0161] Thus, in the modified version of Embodiment 4, after the machining step 1003, the re-cutting step and the re-machining step are repeated one or more times each, thereby separating the circular recess 210 from the annular protrusion 211 with the first cutting blade 21-1 and removing the annular protrusion 211 with the second cutting blade 21-2.

[0162] The processing apparatus 1 and processing method according to the modified embodiment 4 process the boundary between the circular recess 210 and the annular protrusion 211 with the first cutting blade 21-1 and process the annular protrusion 211 with the second cutting blade 21-2. Similar to embodiment 1, this reduces processing time and suppresses the occurrence of cracks when removing the annular protrusion 211 on the outer circumference of the wafer 200.

[0163] In the modified version of Embodiment 4, the processing apparatus 1 and processing method perform the processing step 1003 while detecting the remaining portion of the annular protrusion 211 in the remaining portion detection step 1010, thereby suppressing the creation of holes in the tape 221 by processing the tape 221 with the second cutting blade 21-2.

[0164] Furthermore, in Embodiment 4 and its modified form, the wafer 200 may be processed with the surface 201 side of the wafer 200 held on the holding surface 11 of the holding unit 10, with the annular protrusion 211 facing upward. Also, in Embodiment 4 and its modified form, the wafer 200 may be processed with a protective tape 220 such as that of Embodiment 1 attached to the surface 201 without being supported by the annular frame 222. Furthermore, in Embodiment 4 and its modified form, the wafer 200 may not be fixed to the tape 221, but may be directly held by the holding unit 10 and processed as a single unit.

[0165] 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 principles of the present invention. For example, in the present invention, a grinding wheel or a cup wheel may be used as the second grinding wheel. [Explanation of Symbols]

[0166] 1 Processing equipment 10 Holding Units 21-1 First cutting blade (first grinding wheel) 21-2 Second cutting blade (second grinding wheel) 40 Mobile Units 200 wafers 201 Surface 206 Back side 210 Circular recess (recess) 211 Annular protrusion (protrusion) 213 Outer edge (boundary) 221 Tape 1002 Cutting step 1003 Machining Steps 1004 Cutting step (cutting step, processing step) 1005 Recutting and reworking step (recutting step, reworking step) 1007 Re-cutting step 1008 Reworking step 1010 Residual part detection step

Claims

1. A method for processing a wafer having a recess formed in the center and a convex portion surrounding the recess, A cutting step in which a first grinding wheel is used to cut into the boundary between the recess and the protrusion of the wafer, and a second grinding wheel is used to cut into the protrusion of the wafer, The process includes a step of moving the wafer relative to the first grinding wheel and the second grinding wheel, with the first grinding wheel cutting into the boundary and the second grinding wheel cutting into the protrusion, thereby performing annular processing on the boundary with the first grinding wheel and annular processing on the protrusion with the second grinding wheel, A machining method characterized in that the first grinding wheel and the second grinding wheel each contain abrasive grains, and the average abrasive grain size of the first grinding wheel is smaller than the average abrasive grain size of the second grinding wheel.

2. After performing the machining step, a re-cutting step is performed in which the first grinding wheel cuts deeper into the boundary portion than in the cutting step, and the second grinding wheel cuts deeper into the protrusion portion than in the cutting step, The process includes a reprocessing step in which, with the first grinding wheel cutting deeper into the boundary portion than the cutting step and the second grinding wheel cutting deeper into the protrusion portion than the cutting step, the wafer is moved relative to the first grinding wheel and the second grinding wheel, thereby performing annular processing on the boundary portion with the first grinding wheel and annular processing on the protrusion portion with the second grinding wheel, The machining method according to claim 1, wherein after the machining step, the re-cutting step and the re-machining step are repeated one or more times, thereby cutting the boundary portion with the first grinding wheel and cutting the protrusion portion with the second grinding wheel.

3. The processing method according to claim 1, wherein in the cutting step, the first grinding wheel is made to cut into the wafer to a depth such that the first grinding wheel completely cuts the wafer in the thickness direction, and the second grinding wheel is made to cut into the wafer to a depth such that the second grinding wheel completely cuts the wafer in the thickness direction.

4. After performing the processing step, a re-cutting step is performed in which the first grinding wheel is made to cut into the wafer in the radial direction at a position different from the cutting step, and the second grinding wheel is made to cut into the wafer in the radial direction at a position different from the cutting step, The process includes a reprocessing step in which, with the first grinding wheel cutting into the wafer at a position different from the cutting step in the radial direction of the wafer and the second grinding wheel cutting into the wafer at a position different from the cutting step in the radial direction of the wafer, the wafer is moved relative to the first grinding wheel and the second grinding wheel, thereby performing annular processing on the boundary portion with the first grinding wheel and annular processing on the convex portion with the second grinding wheel, The machining method according to claim 3, wherein after the machining step, the re-cutting step and the re-machining step are repeated one or more times each, thereby separating the recess from the protrusion with the second grinding wheel and removing the protrusion with the second grinding wheel.

5. The recess is formed on the back surface of the wafer's surface, and the tape is arranged on the back surface of the wafer. The processing method according to claim 3, wherein in the cutting step, the first grinding wheel and the second grinding wheel are made to cut to a depth from the surface of the wafer to the tape.

6. After performing the processing step, the protrusion is imaged, The processing method according to claim 3, further comprising a residual portion detection step for detecting the remaining portion of the convex portion in the radial direction of the wafer.

7. A processing apparatus for processing a wafer having a recess formed in the center and a protrusion surrounding the recess, A holding unit for holding the wafer, A first grinding wheel that cuts into the boundary between the recess and the protrusion of the wafer held by the holding unit, A second grinding wheel that cuts into the protrusion of the wafer held by the holding unit, The system includes a moving unit that moves the wafer relative to the first grinding wheel and the second grinding wheel while the first grinding wheel is cutting into the boundary portion and the second grinding wheel is cutting into the convex portion, A processing apparatus characterized in that the first grinding wheel and the second grinding wheel each contain abrasive grains, and the average abrasive grain size of the first grinding wheel is smaller than the average abrasive grain size of the second grinding wheel.

Images