Processing device

Abstract

To recognize whether one sheet of protective tape is stuck to a wafer.SOLUTION: A determination section 143 of a detection unit 140 determines whether a protective tape 103 is stuck to a surface 101 of a wafer 100 and whether the number of the stuck protective tape 103 is one sheet or a plurality of sheets. When one sheet of the protective tape 103 is stuck to the surface 101 of the wafer 100, grinding is executed on the wafer 100. Therefore, thickness of the wafer 100 including the protective tape 103 can be properly set in grinding, and thereby the wafer 100 can be ground into prescribed thickness. Namely, it is possible to avoid grinding insufficiency of the water 100 caused by no-sticking of the protective tape 103 and excessive grinding of the wafer 100 caused by sticking of a plurality of sheets of the protective tapes 103.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a processing apparatus.

Background Art

[0002] As disclosed in Patent Document 1, when grinding the back surface of a wafer, a protective tape is attached to the front surface of the wafer. The variety of the protective tape is identified as disclosed in Patent Document 2, for example.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the protective tape is transparent or the like, two protective tapes may be attached to the wafer. In this way, if two protective tapes are attached to the wafer, even if the protective tape is of an appropriate variety, it becomes difficult to grind the wafer to a predetermined thickness.

[0005] Therefore, an object of the present invention is to recognize whether a protective tape is attached to a wafer and whether the number of attached protective tapes is one or plural.

Means for Solving the Problems

[0006] The processing apparatus (this processing apparatus) of the present invention includes a chuck table that holds a wafer by a holding surface via a protective tape attached to the surface of the wafer, and a processing unit that processes the wafer held on the holding surface. The processing apparatus further includes a detection unit, and the detection unit includes a light projecting unit that irradiates light toward the surface side of the wafer, a light receiving unit that receives the reflected light reflected on the surface side of the wafer, and a determination unit that determines whether or not the protective tape is attached to the surface of the wafer and whether the attached protective tape is one sheet or a plurality of sheets based on the amount of the reflected light received by the light receiving unit.

[0007] In this processing apparatus, the determination unit may be configured to determine whether or not a protective tape of an appropriate type and number of sheets is attached to the surface of the wafer based on the amount of the reflected light received by the light receiving unit.

Effects of the Invention

[0008] In this processing apparatus, the determination unit of the detection unit determines whether or not a protective tape is attached to the surface of the wafer and whether the attached protective tape is one sheet or a plurality of sheets. Therefore, for example, it becomes easy to perform control such that processing on the wafer is performed when one protective tape is attached to the surface of the wafer, while processing is not performed in other cases. As a result, it becomes possible to process the wafer to a predetermined thickness. That is, it is possible to avoid processing defects of the wafer caused by the fact that the protective tape is not attached or that a plurality of protective tapes are attached unintentionally.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

DETAILED DESCRIPTION OF THE INVENTION

[0010] As shown in FIG. 1, the grinding apparatus 1 according to the present embodiment is an example of a processing apparatus, and is an apparatus for grinding a wafer 100 as a workpiece. The wafer 100 is, for example, a circular plate-shaped workpiece, and has a front surface 101 and a back surface 102. Devices (not shown) are formed on the front surface 101 of the wafer 100, and a protective tape 103 is attached thereto. The back surface 102 of the wafer 100 is a surface to be processed on which a grinding process is performed. Further, a notch 104 for indicating the orientation of the wafer 100 is formed on the outer peripheral edge of the wafer 100.

[0011] The grinding apparatus 1 has a first apparatus base 10 and a second apparatus base 11 disposed behind the first apparatus base 10 (on the +Y direction side).

[0012] On the front side (-Y direction side) of the first device base 10, a first cassette stage 160 and a second cassette stage 162 are provided. On the first cassette stage 160 and the second cassette stage 162, a first cassette 161 and a second cassette 163 are placed respectively.

[0013] As shown in FIG. 2, the first cassette 161 and the second cassette 163 each have a plurality of shelves 164 inside, and wafers 100 are accommodated on each shelf 164 one by one with the surface 101 side facing upward.

[0014] Note that each shelf 164 is composed of a flat plate with a circular or rectangular notch in its central region. Therefore, each shelf 164 accommodates one wafer 100 while supporting the outer peripheral region of its back surface 102. In the example shown in FIG. 2, a wafer 100 with two protective tapes 103 attached to its surface 101 and a wafer 100 with one protective tape 103 attached to its surface 101 are shown.

[0015] A robot 150 is disposed near the openings of the first cassette 161 and the second cassette 163. The robot 150 is equipped with a robot hand 151 for holding the wafer 100. The robot 150 transports the wafer 100 held by the robot hand 151. The robot hand 151 has a suction surface 151a for sucking and holding the wafer 100.

[0016] Also, the robot 150 has a drive unit 152 for driving the robot hand 151. The drive unit 152 controls (adjusts) the position and posture of the robot hand 151. Specifically, the drive unit 152 includes a reversal mechanism 153, a lifting mechanism 154, and a horizontal movement mechanism 155. The reversal mechanism 153 reverses the robot hand 151. The lifting mechanism 154 moves the robot hand 151 in the vertical direction along the Z-axis direction. The horizontal movement mechanism 155 moves the robot hand 151 in the horizontal direction.

[0017] The robot 150 carries (stores) the processed wafer 100 held by the robot hand 151 into the first cassette 161 or the second cassette 163. Further, the robot 150 takes out the wafer 100 before processing from the first cassette 161 or the second cassette 163 by the robot hand 151 and places it on the temporary placement table 131 of the temporary placement mechanism 130 shown in FIG. 1.

[0018] The temporary placement mechanism 130 is used to temporarily place the wafer 100 taken out from the first cassette 161 or the second cassette 163, and is provided at a position adjacent to the robot 150. As shown in FIG. 3, the temporary placement mechanism 130 includes a temporary placement table 131 for temporarily placing the wafer 100, a plurality of centering pins 132 for aligning the position of the wafer 100, a base plate 133 for supporting the temporary placement table 131 and the centering pins 132, a rotation mechanism 134 for rotating the temporary placement table 131, and a notch detection sensor 145.

[0019] The centering pin 132 can move toward the center in the radial direction of the temporary placement table 131 on the base plate 133 by the centering pin moving mechanism 132a. Thereby, the wafer 100 placed on the temporary placement table 131 is aligned (centered) at a predetermined position where the center of the temporary placement table 131 coincides with the center of the wafer 100.

[0020] The temporary placement table 131 can suck and hold the centered wafer 100 by being communicated with the suction source 200.

[0021] The rotation mechanism 134 includes a motor 135, a drive pulley 136 attached to the motor 135, a spindle 137 connected to the bottom surface of the temporary placement table 131, a driven pulley 138 attached to the proximal end side of the spindle 137, and an endless belt 139 connecting the drive pulley 136 and the driven pulley 138. The motor 135 is fixed to the lower surface of the base plate 133 via a coupling 135a. The spindle 137 is rotatably supported by the base plate 133 via a bearing 137a.

[0022] The rotation mechanism 134 having such a configuration is configured to rotate the temporary placement table 131 connected to the spindle 137 by rotating the spindle 137 by the driving force of the motor 135.

[0023] The notch detection sensor 145 has a light irradiation unit 146 that irradiates light to the outer peripheral edge of the rotating wafer 100, and a light sensor unit 147 that is disposed below the light irradiation unit 146 and detects the light irradiated from the light irradiation unit 146. The notch detection sensor 145 is configured such that when the notch 104 of the wafer 100 is disposed below the light irradiation unit 146, the light irradiated from the light irradiation unit 146 reaches the light sensor unit 147 via the notch 104. Therefore, based on the light reception state of the light sensor unit 147, it is possible to detect the position of the notch 104 in the wafer 100.

[0024] Also, as shown in FIG. 1, a loading mechanism 170 is provided at a position adjacent to the temporary placement mechanism 130. The loading mechanism 170 holds the wafer 100 taken out by the robot 150 and aligned on the temporary placement table 131, and places it on the holding surface 22 of the chuck table 20.

[0025] An opening 13 is provided on the upper surface side of the second apparatus base 11. And a chuck table 20 having a holding surface 22 for holding the wafer 100 is disposed in the opening 13.

[0026] The chuck table 20 includes a porous member 21 and a frame body 23 that houses the porous member 21 such that the upper surface of the porous member 21 is exposed. The upper surface of the porous member 21 is a holding surface 22 that sucks and holds the wafer 100. The holding surface 22 sucks and holds the surface 101 side of the wafer 100 by being communicated with a suction source (not shown). That is, the chuck table 20 holds the wafer 100 by the holding surface 22 via the protective tape 103 attached to the surface 101 of the wafer 100. Further, a frame surface 24 that is the upper surface of the frame body 23 surrounds the holding surface 22 and is formed to be flush with the holding surface 22 (flush).

[0027] The chuck table 20 is rotatable about a rotation axis passing through the center of the holding surface 22 while holding the wafer 100 by the holding surface 22 by a table rotation mechanism (not shown) provided below it.

[0028] Further, the chuck table 20 can be moved in the Y-axis direction by a table movement mechanism (not shown) provided in the second apparatus base 11. In the present embodiment, the chuck table 20 moves along the Y-axis direction between a wafer placement position on the -Y direction side for holding the wafer 100 on the holding surface 22 and a processing position on the +Y direction side where the wafer 100 held on the holding surface 22 is ground.

[0029] A cover plate 39 that moves along the Y-axis direction together with the chuck table 20 is provided around the chuck table 20. Further, a bellows cover 12 that expands and contracts in the Y-axis direction is connected to the cover plate 39.

[0030] Further, a column 15 is erected on the +Y direction side of the second apparatus base 11. A grinding mechanism 70 for grinding the wafer 100 and a grinding feed mechanism 60 are provided on the front surface of the column 15.

[0031] The grinding feed mechanism 60 relatively moves the chuck table 20 and the grinding wheel 77 of the grinding mechanism 70 in the Z-axis direction (grinding feed direction) perpendicular to the holding surface 22. In the present embodiment, the grinding feed mechanism 60 is configured to move the grinding wheel 77 in the Z-axis direction with respect to the chuck table 20.

[0032] The grinding feed mechanism 60 includes a pair of Z-axis guide rails 61 parallel to the Z-axis direction, a Z-axis moving table 63 that slides on the Z-axis guide rails 61, a Z-axis ball screw 62 parallel to the Z-axis guide rails 61, a Z-axis motor 64, and a holder 66 attached to the Z-axis moving table 63. The holder 66 supports the grinding mechanism 70.

[0033] The Z-axis moving table 63 is slidably installed on the Z-axis guide rails 61. A nut portion (not shown) is fixed to the Z-axis moving table 63. The Z-axis ball screw 62 is screwed into this nut portion. The Z-axis motor 64 is connected to one end of the Z-axis ball screw 62.

[0034] In the grinding feed mechanism 60, when the Z-axis motor 64 rotates the Z-axis ball screw 62, the Z-axis moving table 63 moves in the Z-axis direction along the Z-axis guide rails 61. As a result, the holder 66 attached to the Z-axis moving table 63 and the grinding mechanism 70 supported by the holder 66 also move in the Z-axis direction together with the Z-axis moving table 63.

[0035] The grinding mechanism 70 is an example of a processing unit that processes the wafer 100 held on the holding surface 22 of the chuck table 20. In the present embodiment, the grinding mechanism 70 is configured to grind the back surface 102 of the wafer 100 held on the chuck table 20 with the grinding wheel 77.

[0036] The grinding mechanism 70 includes a spindle housing 71 fixed to the holder 66, a spindle 72 rotatably held by the spindle housing 71, a spindle motor 73 that rotationally drives the spindle 72, a wheel mount 74 attached to the lower end of the spindle 72, and a grinding wheel 75 supported by the wheel mount 74.

[0037] The spindle housing 71 is held by the holder 66 so as to extend in the Z-axis direction. The spindle 72 extends in the Z-axis direction so as to be orthogonal to the holding surface 22 of the chuck table 20 and is rotatably supported by the spindle housing 71.

[0038] The spindle motor 73 is connected to the upper end side of the spindle 72. By this spindle motor 73, the spindle 72 rotates about a rotation axis extending in the Z-axis direction.

[0039] The wheel mount 74 is formed in a disk shape and is fixed to the lower end (tip) of the spindle 72. The wheel mount 74 supports the grinding wheel 75.

[0040] The grinding wheel 75 is formed so that its outer diameter is substantially the same as the outer diameter of the wheel mount 74. The grinding wheel 75 includes an annular wheel base 76 formed of a metal material. A plurality of grinding wheels 77 arranged in an annular shape are fixed to the lower surface of the wheel base 76 over the entire circumference. The grinding wheels 77 are rotated by the spindle motor 73 together with the spindle 72 about its center axis and grind the back surface 102 of the wafer 100 held by the chuck table 20.

[0041] Also, as shown in FIG. 1, a thickness measuring device 80 is disposed on the side portion of the opening 13 in the second apparatus base 11.

[0042] The thickness measuring device 80 has a holding surface height gauge 81 and an upper surface height gauge 82. The holding surface height gauge 81 measures the height of the holding surface 22 by contacting the frame surface 24 of the frame body 23 that is on the same plane as the holding surface 22 of the chuck table 20. The upper surface height gauge 82 measures the height of the back surface 102, which is the upper surface of the wafer 100 held on the holding surface 22, by contacting the back surface 102. Then, the thickness measuring device 80 calculates the thickness of the wafer 100 based on the difference between the measured value of the holding surface height gauge 81 and the measured value of the upper surface height gauge 82.

[0043] Note that the holding surface height gauge 81 and the upper surface height gauge 82 of the thickness measuring device 80 may be non-contact type height gauges. For example, the holding surface height gauge 81 and the upper surface height gauge 82 may be configured to measure the height of the holding surface 22 and the height of the back surface 102 of the wafer 100 based on the reflected light (reflected wave) of the laser beam (or sound wave) irradiated on the frame surface 24 of the frame body 23 and the back surface 102 of the wafer 100.

[0044] The ground wafer 100 is carried out by the carry-out mechanism 172. The carry-out mechanism 172 holds the wafer 100 held on the chuck table 20 and transports it to the spinner table 157 of the single-wafer type spinner cleaning mechanism 156.

[0045] The spinner cleaning mechanism 156 is a spinner cleaning unit that cleans the wafer 100 ground by the grinding mechanism 70. The spinner cleaning mechanism 156 includes a spinner table 157 that holds the wafer 100, and a nozzle 158 that injects cleaning water and drying air toward the spinner table 157.

[0046] In the spinner cleaning mechanism 156, the spinner table 157 holding the wafer 100 rotates, and cleaning water is injected toward the wafer 100, and the wafer 100 is spin-cleaned. Then, drying air is blown onto the wafer 100, and the wafer 100 is dried.

[0047] The wafer 100 cleaned by the spinner cleaning mechanism 156 is carried out of the spinner cleaning mechanism 156 by the robot 150 and carried into the first cassette 161 or the second cassette 163 (the cassette from which this wafer 100 was taken out).

[0048] Further, the grinding device 1 includes a housing 16 that covers the first device base 10 and the second device base 11. A touch panel 8 is installed on the side surface of the housing 16. Various information such as processing conditions related to the grinding device 1 is displayed on the touch panel 8. Also, the touch panel 8 is also used to set various information. Thus, the touch panel 8 functions as a display member for displaying information and also functions as an input member for inputting information.

[0049] Further, the grinding device 1 has a control unit 7 for controlling the grinding device 1 inside it. The control unit 7 includes a CPU that performs arithmetic processing according to a control program, and a storage medium such as a memory. The control unit 7 executes various processes and comprehensively controls each component of the grinding device 1.

[0050] For example, the control unit 7 controls each component of the grinding device 1 to perform the grinding process of the wafer 100. Also, at that time, the control unit 7 also controls the operation of determining the presence and number of the protective tapes 103 attached to the surface 101 of the wafer 100. The detection unit 140 shown in FIG. 3 is used for determining the presence and number of the protective tapes 103.

[0051] The detection unit 140 provided in the grinding device 1 is for detecting the presence and number of the protective tapes 103 on the wafer 100. The detection unit 140 is arranged, for example, between the two centering pins 132 on the base plate 133 of the temporary placement mechanism 130 as shown in FIG. 1.

[0052] As shown in FIG. 4, the detection unit 140 includes a light projecting unit 141 that irradiates light (measurement light L1) toward the surface 101 side of the wafer 100 held on the temporary table 131, a light receiving unit 142 that receives the reflected light L2 reflected on the surface 101 side of the wafer 100, and a determination unit 143.

[0053] Based on the amount of the reflected light (light reception amount) received by the light receiving unit 142, the determination unit 143 determines whether or not the protective tape 103 is attached to the surface 101 of the wafer 100, and whether the attached protective tape 103 is a single sheet or a plurality of sheets.

[0054] Hereinafter, the processing operation of the wafer 100 including the determination operation of the presence or absence and the number of the protective tapes 103 on the wafer 100, which is performed under the control of the control unit 7, will be described. In the following description, it is assumed that the control unit 7 processes the wafer 100 accommodated in the first cassette 161 shown in FIG. 1.

[0055] First, the control unit 7 takes out the wafer 100 before processing from the first cassette 161. As described above, in the first cassette 161, the outer peripheral region of the back surface 102 of the wafer 100 is supported by the shelf 164 (see FIG. 2).

[0056] Therefore, when taking out the wafer 100 from the first cassette 161, the control unit 7 uses the inversion mechanism 153, the lifting mechanism 154, and the horizontal movement mechanism 155 of the robot 150 to place the robot hand 151 below the center of the back surface 102 of the wafer 100 on the shelf 164 so that the suction surface 151a faces upward. Then, as shown in FIG. 5, the control unit 7 sucks and holds the central portion of the back surface 102 of the wafer 100 by the suction surface 151a of the robot hand 151, and takes out the wafer 100 from the shelf 164 using the lifting mechanism 154 and the horizontal movement mechanism 155.

[0057] Furthermore, as shown in FIG. 3, the control unit 7 causes the robot hand 151 to be inverted by the inversion mechanism 153 so that the back surface 102 of the wafer 100 faces upward. Thereafter, the control unit 7 uses the lifting mechanism 154 and the horizontal movement mechanism 155 to convey the wafer 100 held by the robot hand 151 to the temporary placement table 131 of the temporary placement mechanism 130, place the wafer 100 thereon with the back surface 102 facing up.

[0058] At the time of this conveyance, the control unit 7 uses the detection unit 140 to determine the presence and number of the protective tapes 103. That is, as shown in FIG. 4, the control unit 7 irradiates the measurement light L1 from the light projecting unit 141 of the detection unit 140 toward the surface 101 side of the wafer 100 passing above the detection unit 140. This measurement light L1 is reflected on the surface 101 side of the wafer 100, and the reflected light L2 is received by the light receiving unit 142. Then, the determination unit 143 determines the presence and number of the protective tapes 103 on the wafer 100 based on the amount of the reflected light L2 received by the light receiving unit 142.

[0059] When the protective tape 103 is not attached to the surface 101 of the wafer 100, the measurement light L1 is directly irradiated onto the surface 101 of the wafer 100 to become the reflected light L2, which is received by the light receiving unit 142 as it is.

[0060] On the other hand, when the protective tape 103 is attached to the surface 101 of the wafer 100, as shown in FIG. 4, the measurement light L1 passes through the protective tape 103, is reflected by the surface 101 of the wafer 100 to become the reflected light L2, and passes through the protective tape 103 again to be received by the light receiving unit 142. Therefore, in this case, for example, since a part of the measurement light L1 and the reflected light L2 is scattered or absorbed by the protective tape 103, the amount of light received by the light receiving unit 142 is less than the case where the protective tape 103 is not attached to the surface 101 of the wafer 100. Further, when the number of the protective tapes 103 is two or more (a plurality of sheets), it is more than the case where the number of the protective tapes 103 is one sheet.

[0061] Therefore, the determination unit 143 of the detection unit 140 determines, for example, whether the protective tape 103 is adhered to the surface 101 of the wafer 100 and whether the number of adhered protective tapes 103 is one or plural, using the light reception amount of the light reception unit 142 and the preset first threshold value and second threshold value (smaller than the first threshold value).

[0062] That is, as shown in FIG. 6, when the light reception amount of the light reception unit 142 is equal to or greater than the first threshold value, the determination unit 143 determines that the protective tape 103 is not adhered to the surface 101 of the wafer 100. Further, when the light reception amount of the light reception unit 142 is smaller than the first threshold value and equal to or greater than the second threshold value, the determination unit 143 determines that one protective tape 103 is adhered to the surface 101 of the wafer 100. Furthermore, when the light reception amount of the light reception unit 142 is smaller than the second threshold value, the determination unit 143 determines that a plurality of protective tapes 103 are adhered to the surface 101 of the wafer 100. In this way, the determination operation of the presence or absence and the number of the protective tapes 103 on the wafer 100 is completed.

[0063] Thereafter, the control unit 7 performs processing according to the determination result of the presence or absence and the number of the protective tapes 103 by the determination unit 143. For example, when it is determined by the determination unit 143 that a plurality of protective tapes 103 are adhered to the surface 101 of the wafer 100 and when it is determined that the protective tape 103 is not adhered, before the wafer 100 is placed on the temporary placement table 131, the control unit 7 controls the robot hand 151 holding the wafer 100 using the elevating mechanism 154 and the horizontal movement mechanism 155 to return the wafer 100 to the first cassette 161. Further, the control unit 7 notifies the operator of the determination result by the determination unit 143 using the touch panel 8 shown in FIG. 1.

[0064] On the other hand, when the determination unit 14 determines that one protective tape 103 is adhered to the surface 101 of the wafer 100, the control unit 7 controls the robot hand 151 holding the wafer 100 by using the elevating mechanism 154 and the horizontal movement mechanism 155, and places the wafer 100 on the temporary placement table 131.

[0065] Next, the control unit 7 irradiates the wafer 100 with the measurement light L1 from the light emitting unit 141 of the detection unit 140, and receives the reflected light L2 by the light receiving unit 142. Thereby, the control unit 7 confirms that the wafer 100 is placed on the temporary placement table 131. After that, the control unit 7 performs centering of the wafer 100 by using the centering pin 132.

[0066] Furthermore, as shown in FIG. 6, the control unit 7 sucks and holds the wafer 100 by the temporary placement table 131, and rotates the temporary placement table 131 by using the rotation mechanism 134. Then, light is irradiated from the light irradiation unit 146 of the notch detection sensor 145 to the outer peripheral edge of the wafer 100 that rotates together with the temporary placement table 131. Then, the control unit 7 detects the position of the notch 104 (see FIG. 1) of the wafer 100 based on the light reception state of the light sensor unit 147, and adjusts the orientation of the wafer 100.

[0067] Next, the control unit 7 uses the loading mechanism 170 to load the wafer 100 onto the chuck table 20, and performs grinding of the wafer 100 using the grinding feed mechanism 60 and the grinding mechanism 70, and cleaning of the wafer 100 using the spinner cleaning mechanism 156.

[0068] As described above, in the present embodiment, the determination unit 143 of the detection unit 140 determines whether or not the protective tape 103 is adhered to the surface 101 of the wafer 100, and whether the adhered protective tape 103 is a single sheet or a plurality of sheets. Then, when a single protective tape 103 is adhered to the surface 101 of the wafer 100, the control unit 7 performs grinding on the wafer 100. Therefore, during the grinding process, the thickness of the wafer 100 including the protective tape 103 can be appropriately set, so that the wafer 100 can be ground to a predetermined thickness. That is, before the grinding process, the thickness of the wafer 100 is measured, and when the thickness of the wafer 100 including the protective tape 103 measured by the thickness measuring device 80 is different from the preset thickness of the wafer 100 before grinding (input thickness), the unproductive operation of recovering the wafer 100 held on the chuck table 20 can be eliminated.

[0069] In addition, as shown in FIG. 3, in the present embodiment, when the wafer 100 is transported to the temporary placement table 131 by the robot hand 151, the measurement light L1 is irradiated onto the wafer 100 passing above the detection unit 140 to determine the presence or absence and the number of the protective tapes 103. In this regard, instead of or in addition to this determination, the measurement light L1 may be irradiated onto the wafer 100 placed on the temporary placement table 131 of the temporary placement mechanism 130 to determine the presence or absence and the number of the protective tapes 103.

[0070] In this case, the control unit 7 places the wafer 100 on the temporary placement table 131 by the robot hand 151, performs centering on the wafer 100, and then, as shown in FIG. 7, sucks and holds the wafer 100 by the temporary placement table 131 to perform notch detection. After that, the control unit 7 irradiates the measurement light L1 from the light projecting unit 141 of the detection unit 140 toward the surface 101 side of the wafer 100, and the reflected light L2 is received by the light receiving unit 142. Further, as described above, the determination unit 143 determines the presence or absence and the number of the protective tapes 103 on the wafer 100 using the light reception amount of the light receiving unit 142, the first threshold value, and the second threshold value.

[0071] In this configuration, for example, when the determination unit 14 determines that a plurality of protective tapes 103 are attached to the wafer 100, and when it is determined that no protective tape 103 is attached, the control unit 7 causes the robot 150 to return the wafer 100 placed on the temporary placement table 131 to the first cassette 161. Further, the control unit 7 uses the touch panel 8 shown in FIG. 1 to notify the operator of the result of the determination by the determination unit 143. On the other hand, when the determination unit 14 determines that one protective tape 103 is attached to the surface 101 of the wafer 100, the control unit 7 uses the loading mechanism 170 to load the wafer 100 onto the chuck table 20, and performs grinding of the wafer 100 using the grinding feed mechanism 60 and the grinding mechanism 70, and cleaning of the wafer 100 using the spinner cleaning mechanism 156.

[0072] Further, the control unit 7 may irradiate the surface 101 side of the wafer 100 with measurement light L1 at a plurality of locations. Then, the determination unit 143 may determine whether a protective tape 103 is attached to the surface 101 of the wafer 100 and whether the attached protective tape 103 is one or a plurality based on the reflected light L2 from the plurality of locations. For example, the control unit 7 may be set to irradiate the measurement light L1 at the five measurement points M1 to M5 shown in FIG. 8.

[0073] In this case, the control unit 7 performs measurement (determination of the presence or absence and number of protective tapes 103) using the measurement point M2 on the wafer 100 passing above the detection unit 140, for example, as shown in FIG. 3.

[0074] Further, the control unit 7 performs measurements using the measurement points M1, M3 to M5 on the wafer 100 held on the temporary table 131, for example, as shown in FIG. 7. At this time, after the control unit 7 sucks and holds the wafer 100 by the temporary table 131, the control unit 7 rotates the temporary table 131 using the rotation mechanism 134. Then, measurement light L1 is irradiated from the light projecting unit 141 of the detection unit 140 to each of the measurement points M1, M3 to M5 of the wafer 100 that rotates together with the temporary table 131, and the reflected light L2 is received by the light receiving unit 142.

[0075] Then, after the determination unit 143 acquires the light reception amounts of the light receiving unit 142 at the measurement points M1 to M5 respectively, the determination unit 143 calculates the average value thereof. Further, the determination unit 143 determines the presence or absence and the number of the protective tapes 103 on the wafer 100 using the calculated average value of the light reception amounts, the first threshold value, and the second threshold value.

[0076] Here, an adhesive layer for attaching the protective tape 103 to the surface 101 of the wafer 100 is formed on the protective tape 103. If there is unevenness in this adhesive layer, the light reception amount of the light receiving unit 142 may deviate from an appropriate value corresponding to the presence or absence and the number of the protective tapes 103. Regarding this, in the above configuration, since the average value of the light reception amounts obtained from the plurality of measurement points M1 to M5 is used, it is possible to reduce the influence of the unevenness of the adhesive of the protective tape 103. Therefore, it becomes easy to acquire an appropriate light reception amount corresponding to the presence or absence and the number of the protective tapes 103.

[0077] Also, as described above, the determination unit 143 determines the presence or absence and the number of the protective tapes 103 based on the light reception amount of the light receiving unit 142. And the determination unit 143 can use, for example, the total amount of the reflected light L2 received by the light receiving unit 142 (the light amount including the R component, the G component, and the B component of the reflected light L2) as the light reception amount of the light receiving unit 142.

[0078] Note that the protective tape 103 comes in various types depending on the application and the like. For example, there are transparent ones, colored ones, thin ones, thick ones, and so on. And, for example, when one blue protective tape 103 is attached to the wafer 100 and when two transparent protective tapes 103 are attached to the wafer 100, the total amount of the reflected light L2 received by the light receiving unit 142 may be substantially equal.

[0079] Therefore, it is preferable that the determination unit 143 is configured to determine whether an appropriate type and number (for example, one sheet) of the protective tape 103 is attached to the surface 101 of the wafer 100 based on the amount of the reflected light L2 received by the light receiving unit 142.

[0080] Specifically, the determination unit 143 may obtain the light amounts of the R component, G component, and B component of the reflected light L2 received by the light receiving unit 142 as the light reception amount of the light receiving unit 142, and based on these, determine the type and number of the protective tapes 103. In this case, the light receiving unit 142 is configured to be able to output the light amounts of the respective R component, G component, and B component of the received reflected light L2 to the determination unit 143. And threshold values or determination ranges are set for the light amounts of the respective R component, G component, and B component of the reflected light L2.

[0081] In this case, in the determination operation of the presence / absence and number of the protective tapes 103 on the wafer 100, the determination unit 143 first determines the presence / absence of the protective tape 103 using the total amount of the reflected light L2 received by the light receiving unit 142 and the first threshold value described above.

[0082] And when it is determined that there is the protective tape 103, the determination unit 143 continues to determine the type (color and / or thickness, etc.) and number of the protective tapes 103 using the R component, G component, and B component of the reflected light L2.

[0083] Figures 9(a) to (c) show the amounts of light in the R, G, and B components of the reflected light L2 received by the light receiving unit 142 when one or two of three types of protective tapes 103 (blue A, transparent A, blue B) are adhered to the wafer 100 (cases 1 to 6). Figure 9(a) shows the amount of light in the R component, Figure 9(b) shows the amount of light in the G component, and Figure 9(c) shows the amount of light in the B component. Also, the amounts of light shown in these figures are the amounts of light in each component measured at the measurement points M1 to M5 shown in Figure 8, and their average values.

[0084] "Transparent A", which is the type of tape in cases 3 and 4, indicates the transparent protective tape 103. Also, "blue A" and "blue B", which are the types of tape in cases 1, 2, 5, and 6, indicate the blue protective tape 103. Note that the protective tape 103 of "blue A" has strong adhesion. Also, the thickness of the protective tape 103 of "blue A" and the protective tape 103 of "transparent A" is approximately 130 μm, and the thickness of the protective tape 103 of "blue B" is 205 μm. Thus, the protective tape 103 of "blue A" and the protective tape 103 of "transparent A" have the same thickness but different substrate hardnesses. Therefore, it is difficult to detect in the pre-grinding thickness measurement.

[0085] For example, assume that the protective tapes 103 of "transparent A" and "blue A" are mixed, and the protective tape 103 adhered to the wafer 100 is in any of the states of case 1, case 3, and case 4.

[0086] In this case, the control unit 7 sets, for example, the R threshold value, the B threshold value, and the G threshold value shown in FIG. 10. The R threshold value shown in this figure is larger than the light amount of the R component obtained in Case 1 and Case 4, and smaller than the light amount of the R component obtained in Case 3. Also, the G threshold value is larger than the light amount of the G component obtained in Case 1 and Case 4, and smaller than the light amount of the G component obtained in Case 3. Further, the B threshold value is larger than the light amount of the B component obtained in Case 4, and smaller than the light amount of the B component obtained in Case 1 and Case 3. With this configuration, the determination unit 143 can determine whether the protective tape 103 attached to the wafer 100 is in a desired state using these threshold values.

[0087] For example, assume that the determination unit 143 is configured to determine whether the protective tape 103 attached to the wafer 100 is in the state of Case 3. In this case, when the determination unit 143 determines that the light amount of the R component of the reflected light L2 received by the light receiving unit 142 is larger than the R threshold value and / or the light amount of the G component is larger than the G threshold value, it determines that the protective tape 103 attached to the surface 101 of the wafer 100 is in the state of Case 3, that is, it can be determined that a protective tape 103 of an appropriate type (transparent A) and an appropriate number (one sheet) is attached to the surface 101 of the wafer 100.

[0088] Also, the determination unit 143 can also determine whether the protective tape 103 attached to the wafer 100 is in the state of Case 1. In this case, when the determination unit 143 determines that the light amount of the R component (and / or G component) of the reflected light L2 received by the light receiving unit 142 is smaller than the R threshold value (G threshold value) and the light amount of the B component is larger than the B threshold value, it determines that the protective tape 103 is in the state of Case 1.

[0089] Furthermore, the determination unit 143 can also determine whether the protective tape 103 attached to the wafer 100 is in the state of Case 4. In this case, when the determination unit 143 determines that the light amount of the B component of the reflected light L2 received by the light receiving unit 142 is smaller than the B threshold value, it determines that the protective tape 103 is in the state of Case 4.

[0090] Also, when determining whether the protective tape 103 attached to the wafer 100 is in a desired state (for example, Case 3), instead of the above-described R threshold value, B threshold value, and G threshold value, RGB ranges corresponding to each case, for example, the first R range, the first G range, and the first B range shown in FIG. 11 may be used. The first R range, the first G range, and the first B range shown in this figure include the light amounts of the R component, the G component, and the B component obtained in Case 3, and do not include the light amounts of each of Case 1 and Case 4.

[0091] In this case, when the determination unit 143 determines that the light amounts of the R component, the G component, and the B component of the reflected light L2 received by the light receiving unit 142 are respectively within the first R range, the first G range, and the first B range, it determines that the protective tape 103 attached to the surface 101 of the wafer 100 is in the state of Case 3, that is, it can be determined that a protective tape 103 of an appropriate type (transparent A) and an appropriate number (one sheet) is attached to the surface 101 of the wafer 100.

[0092] Also, when determining whether the protective tape 103 attached to the wafer 100 is in the state of Case 4, a second R range, a second G range, and a second B range as shown in FIG. 12 are set. These ranges include the light amounts of the R component, the G component, and the B component obtained in Case 4, and do not include the light amounts of each of Case 1 and Case 3.

[0093] In this case, when the determination unit 143 determines that the light amounts of the R component, G component, and B component of the reflected light L2 received by the light receiving unit 142 are within the second R range, second G range, and second B range, respectively, it determines that the protective tape 103 adhered to the surface 101 of the wafer 100 is in the state of Case 4. That is, it can be determined that a protective tape 103 of an appropriate type (transparent A) and an appropriate number (two sheets) is adhered to the surface 101 of the wafer 100.

[0094] In the above description, after the determination unit 143 determines the presence or absence of the protective tape 103 using the total amount of the reflected light L2, it determines the type and number of the protective tapes 103 using the light amounts of the R component, G component, and B component of the reflected light L2. In this regard, the determination unit 143 may also determine the presence or absence of the protective tape 103 using the light amounts of the R component, G component, and B component of the reflected light L2. In this case, it is preferable to set a threshold value or range regarding the light amounts of the R component, G component, and B component of the reflected light L2 corresponding to the state where the protective tape 103 is absent.

[0095] Also, in the present embodiment, the detection unit 140 is disposed on the base plate 133 of the temporary placement mechanism 130. In this regard, the detection unit 140 may be disposed at any position in the conveyance path of the wafer 100. For example, the detection unit 140 may be disposed near the openings of the first cassette 161 and the second cassette 163. When the wafer 100 is stored in the cassette with the surface 101 facing upward, the detection unit 140 is preferably disposed above the opening in the cassette.

[0096] In the above-described embodiment, as an example of the processing apparatus, a grinding apparatus 1 including a grinding mechanism 70 is shown. In this regard, the processing apparatus according to the present embodiment may be a polishing apparatus that polishes the back surface 102 of the wafer 100. In this case, for example, in the configuration of the grinding apparatus 1, instead of the grinding mechanism 70, the polishing apparatus includes a polishing mechanism having a polishing pad as a processing unit. In this configuration, the polishing apparatus can determine whether or not a single protective tape 103 is attached to the front surface 101 of the wafer 100, and / or can determine whether or not an appropriate type and number of protective tapes 103 are attached to the front surface 101 of the wafer 100. Therefore, it becomes possible to polish the wafer 100 to have an appropriate thickness.

Description of Reference Numerals

[0097] 1: Grinding apparatus, 7: Control unit, 8: Touch panel, 10: First apparatus base, 11: Second apparatus base, 12: Bellows cover, 13: Opening, 15: Column, 16: Housing, 20: Chuck table, 21: Porous member, 22: Holding surface, 23: Frame body, 24: Frame surface, 39: Cover plate, 60: Grinding feed mechanism, 61: Z-axis guide rail, 62: Z-axis ball screw, 63: Z-axis moving table, 64: Z-axis motor, 66: Holder, 70: Grinding mechanism, 71: Spindle housing, 72: Spindle, 73: Spindle motor, 74: Wheel mount, 75: Grinding wheel, 76: Wheel base, 77: Grinding stone, 80: Thickness measuring device, 81: Holding surface height gauge, 82: Upper surface height gauge, 100: Wafer, 101: Front surface, 102: Back surface, 103: Protective tape, 130: Temporary placement mechanism, 131: Temporary placement table, 132: Centering pin, 132a: Centering pin moving mechanism, 133: Base plate, 134: Rotation mechanism, 135: Motor, 135a: Coupling, 136: Driving pulley, 137: Spindle, 137a: Bearing, 138: Driven pulley, 139: Endless belt, 140: Detection unit, 141: Light projecting unit, 142: Light receiving unit, 143: Judgment unit, 145: Notch detection sensor, 146: Light irradiation unit, 147: Light sensor unit, 150: Robot, 151: Robot hand, 151a: Adsorbing surface, 152: Driving unit, 153: Reversing mechanism, 154: Lifting mechanism, 155: Horizontal movement mechanism, 156: Spinner cleaning mechanism, 157: Spinner table, 158: Nozzle, 160: First cassette stage, 161: First cassette, 162: Second cassette stage, 163: Second cassette, 164: Shelf, 170: Loading mechanism, 172: Unloading mechanism, 200: Suction source

Claims

1. A processing apparatus including: a chuck table that holds a wafer with a holding surface via a protective tape attached to a surface of the wafer; and a processing unit that processes the wafer held on the holding surface, Further comprising a detection unit, The detection unit includes: a light projection unit that irradiates light toward a front surface side of the wafer; a light receiving unit that receives light reflected on the front surface side of the wafer; a determination unit that determines whether the protective tape is attached to the front surface of the wafer and whether the number of the protective tapes attached is one or multiple, based on the amount of reflected light received by the light receiving unit; A processing apparatus comprising:

2. the determining unit determines whether or not an appropriate type and number of the protective tapes are attached to the front surface of the wafer based on the amount of reflected light received by the light receiving unit. The processing device according to claim 1 .

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