Wafer end face polishing apparatus

Abstract

To provide a wafer end face polishing device for forming an end face of a wafer into an appropriate shape even if a gap between a first roller and a second roller in a thickness direction of the wafer is made smaller than before.SOLUTION: In the wafer end face polishing device, a polishing mechanism 31 includes a wafer rotating mechanism, a wafer elevating mechanism, a first roller 43, a second roller 44, a roller moving mechanism 25, and a tape transfer mechanism 26. The roller moving mechanism 25 moves both or one of the first roller 43 and the second roller 44 in a direction approaching the 27a portion of the end surface of the wafer 27 supported by the wafer rotating mechanism, and polishes the 27a portion of the end surface of the wafer 27 with the polishing tape 33 transferred between the first roller 43 and the second roller 44. The wafer elevating mechanism elevates and lowers the wafer 27 based on the data of the shape of the end face 27a of the wafer 27, thereby changing the position of the end face 27a of the wafer 27 with which the polishing tape 33 comes into contact in the thickness direction of the wafer 27.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a wafer edge polishing apparatus. [Background technology]

[0002] In recent years, wafer edge polishing devices have been used to polish the edge of a wafer to remove unnecessary films and surface roughness. For example, in a conventional wafer edge polishing device, the wafer is rotated around the central axis of the wafer as the rotation axis, and a polishing tape, which is moved in the thickness direction of the wafer, is brought into sliding contact with the edge of the wafer, thereby polishing the edge of the wafer into an arc shape (see, for example, Patent Document 1).

[0003] In addition, conventional wafer edge polishing devices have a lower variable roller and an upper variable roller positioned to sandwich the wafer, and a polishing tape stretched between the lower variable roller and the upper variable roller is moved in the thickness direction of the wafer, with the lower variable roller and the upper variable roller each being movable in a direction approaching the wafer edge. As a result, in the wafer edge polishing device, by individually moving the lower variable roller and the upper variable roller closer to the wafer, the tilt angle of the polishing tape relative to the wafer edge can be freely changed, and the wafer edge can be polished to an optimal shape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-186176 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional wafer edge polishing apparatuses, the entire wafer edge from the upper corner to the lower corner is polished to an optimal shape by changing the positions of the lower and upper variable rollers that sandwich the wafer in the thickness direction and changing the inclination angle of the polishing tape relative to the wafer edge, so that the lower and upper variable rollers must be positioned to sandwich the wafer so that the entire wafer edge is positioned between the lower and upper variable rollers on which the polishing tape is stretched. Therefore, in order to polish the entire wafer edge to an optimal shape using conventional wafer edge polishing apparatuses, the gap between the lower and upper variable rollers on which the polishing tape is stretched must be greater than or equal to the wafer thickness, so that the entire wafer edge is sandwiched between the lower and upper variable rollers in the thickness direction of the wafer, which poses a problem of increasing the gap between the lower and upper variable rollers in the thickness direction of the wafer.

[0006] This invention has been made in light of the above circumstances, and its object is to provide a wafer edge polishing apparatus that can form the edge of a wafer into an appropriate shape even if the gap between the first roller and the second roller in the thickness direction of the wafer is made smaller than in the past. [Means for solving the problem]

[0007] The wafer edge polishing apparatus according to the present invention includes a wafer rotation mechanism that supports a wafer and rotates the wafer in a circumferential direction around a central axis of the wafer as a rotation axis, a wafer lifting mechanism that raises and lowers the wafer supported by the wafer rotation mechanism in the central axis direction, a first roller disposed radially outward of the wafer supported by the wafer rotation mechanism, a second roller disposed radially outward of the wafer supported by the wafer rotation mechanism and opposed to the first roller in the thickness direction of the wafer, and a polishing tape wound around the first roller and the second roller stretched between the first roller and the second roller, and the polishing tape is moved between the first roller and the second roller. and a roller moving mechanism that moves each of the first roller and the second roller independently in a direction toward and away from the edge face of the wafer, thereby moving the polishing tape in a direction toward and away from the edge face of the wafer, wherein the roller moving mechanism moves both or either of the first roller and the second roller in a direction toward the edge face of the wafer supported by the wafer rotation mechanism, and polishes the edge face of the wafer with the polishing tape being transferred between the first roller and the second roller, and the wafer lifting mechanism lifts and lowers the wafer, thereby changing the position of the edge face of the wafer with which the polishing tape contacts in the thickness direction of the wafer. [Effects of the Invention]

[0008] In the present invention, the first roller and the second roller can independently move toward the wafer edge surface, changing the inclination angle of the polishing tape. In addition, the wafer can be moved along the central axis by a wafer lifting mechanism. This allows the position where the polishing tape contacts the wafer edge surface to be changed by adjusting the inclination angle of the polishing tape. Furthermore, the position where the polishing tape contacts the wafer edge surface can also be changed by changing the height position of the wafer edge surface along the central axis. Therefore, even if the entire wafer edge surface does not necessarily need to be positioned between the first roller and the second roller that transport the polishing tape, the entire wafer edge surface can be polished by appropriately changing the height position of the wafer edge surface. Therefore, even if the gap between the first roller and the second roller in the wafer thickness direction is smaller than in the past, the wafer edge surface can be formed into an appropriate shape. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing the configuration of a wafer processing system having a wafer edge polishing apparatus according to the present invention; [Figure 2] FIG. 2 is a side view showing the configuration of the wafer edge polishing apparatus. [Figure 3] FIG. 2 is a side view showing the configuration of a roller group, a roller moving mechanism, and a tape transfer mechanism. [Figure 4] FIG. 2 is a perspective view showing the configuration of a main part of a roller moving mechanism. [Figure 5] FIG. 3 is an enlarged side view of a main part showing the configuration of a first roller and a second roller. [Figure 6] FIG. 10 is a side view showing the state of the second sanding operation. [Figure 7] FIG. 10 is an enlarged side view of a main part showing the state of the second sanding operation. [Figure 8] FIG. 10 is a side view showing a state of a third sanding operation. [Figure 9] FIG. 10 is an enlarged side view of a main part showing a state of a third sanding operation. [Figure 10] FIG. 1 is a side view showing the configuration of a wafer edge polishing apparatus provided with a plate-shaped back pad. [Figure 11]FIG. 1 is a schematic diagram showing the configuration of a wafer edge polishing apparatus equipped with a tape switching mechanism for switching between two types of polishing tapes with different roughnesses. [Figure 12] 10 is a side view for explaining the configuration of a base plate and a base plate support portion of a wafer edge surface polishing apparatus according to another embodiment. FIG. BEST MODE FOR CARRYING OUT THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a wafer edge polishing apparatus according to the present invention will now be described in detail with reference to the accompanying drawings. In the following description, the same components are designated by the same reference numerals, and duplicated explanations will be omitted.

[0011] 1 is a plan view showing the configuration of a wafer processing system 10 including a wafer edge-face polishing apparatus 17 according to the present invention. Wafer processing system 10 is equipped with four cassette stands 11, 12, 13, and 14, an orientation flat / notch detection apparatus 15, a wafer edge-face inspection apparatus 16, a wafer edge-face polishing apparatus 17, and a transfer machine 18. The four cassette stands 11 to 14, orientation flat / notch detection apparatus 15, wafer edge-face inspection apparatus 16, and wafer edge-face polishing apparatus 17 are arranged in a substantially circular shape with transfer machine 18 at the center so as to surround transfer machine 18.

[0012] The four cassette stands 11-14 are arranged in an arcuate pattern and serve as stands for placing wafer cassettes. Each wafer cassette stores a plurality of approximately disk-shaped wafers. A loader / unloader unit 19 is provided near the four cassette stands 11-14 to receive and unload each of the wafer cassettes.

[0013] Transfer machine 18 loads and unloads wafers into and from wafer cassettes, wafer edge inspection device 16, and wafer edge polishing device 17. Orientation flat and notch detection device 15 inspects the position of the orientation flat and notch formed on the edge of the wafer. The inspection results obtained by orientation flat and notch detection device 15 are used as information for aligning the orientation flat and notch when storing the wafer in a wafer cassette, and for positioning the orientation flat and notch in wafer edge inspection device 16 and wafer edge polishing device 17.

[0014] The wafer edge inspection device 16 inspects the shape of the wafer edge and outputs the inspection results to the wafer edge polishing device 17. Based on the inspection results received from the wafer edge inspection device 16, the wafer edge polishing device 17 polishes the wafer edge into, for example, a circular arc shape in cross section. The wafers whose edge surfaces have been polished are then cleaned. After cleaning, the wafers are transferred to the wafer cassettes placed on the original cassette stands 11 to 14.

[0015] FIG. 2 is a side view showing the configuration of a wafer edge polishing apparatus 17. As shown in FIG. 2, the wafer edge polishing apparatus 17 includes a wafer rotation mechanism 22, a wafer lifting mechanism 23, a roller group 24, a roller movement mechanism 25, and a tape transfer mechanism 26. In FIG. 2, the Z direction indicates the central axis direction of the wafer 27. In FIG. 2, the Y direction indicates the direction in which the roller group 24 (described later) moves toward and away from the wafer 27 and the direction in which the polishing tape moved by the roller group 24 approaches and separates from the edge surface of the wafer 27. These directions are perpendicular to the Z direction. Furthermore, in FIG. 2, the direction perpendicular to the Y and Z directions is indicated as the X direction, and the XY plane including the X and Y directions is the surface direction of the wafer 27.

[0016] The wafer edge surface polishing apparatus 17 is provided with a transfer table 30a, and a wafer 27 is loaded onto the transfer table 30a from the wafer edge surface inspection apparatus 16 by a transfer machine 18 (FIG. 1). The wafer edge surface polishing apparatus 17 is provided with a transfer holder 21 that is movably provided via an arm 20, and the arm 20 is moved to grip the wafer 27 loaded onto the transfer table 30a with the transfer holder 21. Then, the wafer edge surface polishing apparatus 17 transports the transfer holder 21 that is gripping the wafer 27 to a table 30 of the wafer rotation mechanism 22 by the arm 20, and loads the wafer 27 onto the table 30 in an optimal position and orientation.

[0017] The wafer rotation mechanism 22 has a table 30 attached to the upper end of a rotation shaft 29 that is rotated by a drive motor 28, and air is drawn from the top of the table 30 by an air intake unit (not shown). As a result, when a wafer 27 is placed on the table 30, the wafer rotation mechanism 22 vacuum-adsorbs the wafer 27 to the table 30 and supports the wafer 27 by the table 30. By driving the drive motor 28, the wafer rotation mechanism 22 rotates the table 30 about the rotation shaft 29, and rotates the wafer 27 in a circumferential direction within a horizontal plane with the central axis of the wafer 27 as the rotation axis, while the wafer 27 is supported by the table 30.

[0018] The wafer lifting mechanism 23 holds the wafer rotating mechanism 22 and moves the wafer 27 in the central axis direction (Z direction) via the wafer rotating mechanism 22.

[0019] The roller group 24, roller moving mechanism 25, and tape transfer mechanism 26 are collectively referred to as a polishing mechanism 31. The polishing mechanism 31 is provided on a base plate 32. The base plate 32 is configured to be movable in a direction toward or away from the edge face of the wafer 27 (Y direction), and moves the polishing mechanism 31 provided on the base plate 32 in a direction toward or away from the edge face of the wafer 27.

[0020] FIG. 3 is a side view of the main components of the polishing mechanism 31. The roller group 24 is disposed radially outward of the wafer 27, and the polishing tape 33 is tensioned and transported in the thickness direction of the wafer 27. The tape transport mechanism 26 transports the polishing tape 33 toward the roller group 24, applies tension to the polishing tape 33, and transports the polishing tape 33 in a tensioned state across the roller group 24. The polishing tape 33 is, for example, a film coated with ultrafine abrasive particles uniformly dispersed in a resin adhesive. The polishing tape 33 polishes the end surface 27a to a predetermined roughness depending on the grain size of the abrasive. Note that the dashed-dotted line O in FIG. 3 is a reference line indicating the reference in the height direction (Z direction) of the roller group 24.

[0021] In this case, the tape transfer mechanism 26 includes a tape feed reel 34, a tape take-up reel 35, tension rollers 36, 37, motor rollers 38, 39, and pressure rollers 40, 41, and these tape feed reel 34, tape take-up reel 35, tension rollers 36, 37, motor rollers 38, 39, and pressure rollers 40, 41 are mounted on a base plate 32. The tension roller 36, motor roller 38, and pressure roller 40 are disposed on the feed side that transports the polishing tape 33 from the tape feed reel 34 to the group of rollers 24. The tension roller 37, motor roller 39, and pressure roller 41 are disposed on the take-up side that transports the polishing tape 33 from the group of rollers 24 to the tape take-up reel 35.

[0022] The polishing tape 33 unwound from the tape supply reel 34 is bent at the outer peripheral surface of the tension roller 36, guided between the motor roller 38 and the pressure roller 40, and sandwiched between the motor roller 38 and the pressure roller 40, then fed out from between the motor roller 38 and the pressure roller 40, bent at the outer peripheral surface of the motor roller 38 toward the roller group 24, and transported to the roller group 24. The polishing tape 33 transported to the roller group 24 is fed from the roller group 24 toward the motor roller 39, guided along the outer peripheral surface of the motor roller 39 between the motor roller 39 and the pressure roller 41, sandwiched between the motor roller 39 and the pressure roller 41, then fed out from between the motor roller 39 and the pressure roller 41 toward the tension roller 37, bent at the outer peripheral surface of the tension roller 37 toward the tape take-up reel 35, and taken up by the tape take-up reel 35.

[0023] In this way, the tape transfer mechanism 26 transfers the polishing tape 33 to the first roller 43 and the second roller 44 that make up the roller group 24, and stretches the polishing tape 33 wound around the first roller 43 and the second roller 44 between the first roller 43 and the second roller 44, thereby continuously transferring the polishing tape 33 between the first roller 43 and the second roller 44. That is, when polishing the edge surface 27a of the wafer 27, the tape transfer mechanism 26 drives the motor rollers 38, 39 to rotate the motor rollers 38, 39, thereby guiding the polishing tape 33 fed from the tape feed reel 34 along the above-mentioned transfer path to the first roller 43, winding the polishing tape 33 around the outer periphery of the first roller 43 and changing the transfer direction of the polishing tape 33 to extend it toward the second roller 44, winding the polishing tape 33 around the outer periphery of the second roller 44 and changing the transfer direction of the polishing tape 33 to continuously transfer the polishing tape 33 toward the tape take-up reel 35.

[0024] The roller moving mechanism 25 is provided on the base plate 32, and moves together with the base plate 32 in a direction toward or away from the end face 27a of the wafer 27 as the base plate 32 moves in the direction toward or away from the end face 27a of the wafer 27 (Y direction). Here, FIG. 4 is a perspective view showing the configuration of a main part of the roller moving mechanism 25. As shown in FIG. 4, the roller moving mechanism 25 is provided with a first roller 43 and a second roller 44 as the roller group 24, and is configured to move each of the first roller 43 and the second roller 44 independently in a direction toward or away from the end face 27a of the wafer 27 (Y direction) separately from the movement in the Y direction by the base plate 32.

[0025] The first roller 43 and the second roller 44 are disposed opposite each other at a predetermined distance in the thickness direction (Z direction) of the wafer 27, which is perpendicular to the rotation plane of the wafer 27 on the XY plane. The first roller 43 is disposed radially outward of the wafer 27 supported by the wafer rotation mechanism 22 and above the second roller 44. The first roller 43 is supported by an upper moving plate 45 via upper connecting plates 45a and 45b. The upper moving plate 45 is provided so as to be movable in the Y direction (horizontal direction) relative to the base plate 32 (see FIG. 3). As the upper moving plate 45 moves in the Y direction, the first roller 43 moves toward and away from the end surface 27a of the wafer 27 (Y direction) in conjunction with the movement of the upper moving plate 45.

[0026] The upper connecting plates 45a, 45b on which the first roller 43 is provided are plate-like members having a longitudinal direction in the Y direction, and a rod-shaped cross section 45c is hung between the upper connecting plates 45a, 45b, and the first roller 43 is hung between the upper connecting plates 45a, 45b, which are arranged opposite each other at a predetermined distance, and the first roller 43 is hung between the upper connecting plates 45a, 45b, which are arranged opposite each other at a predetermined distance, and each end is rotatably provided at the tip end of the upper connecting plates 45a, 45b.

[0027] The second roller 44 is disposed radially outward of the wafer 27 supported by the wafer rotation mechanism 22, and is disposed below the first roller 43. The second roller 44 is supported by a lower moving plate 46 via lower connecting plates 46a and 46b. The lower moving plate 46 is provided so as to be movable in the Y direction relative to the base plate 32. As the lower moving plate 46 moves in the Y direction, the second roller 44 moves in a direction toward and away from the end surface 27a of the wafer 27 (Y direction) in conjunction with the movement of the lower moving plate 46.

[0028] The lower connecting plates 46a, 46b on which the second roller 44 is provided are plate-like members having their longitudinal direction in the Y direction, and a rod-shaped cross section 46c is hung between the lower connecting plates 46a, 46b, which are arranged opposite each other with a predetermined distance provided by the cross section 46c. The second roller 44 is hung between the lower connecting plates 46a, 46b which are arranged opposite each other with a predetermined distance provided, and each end is rotatably provided at the tip end of the lower connecting plates 46a, 46b.

[0029] The upper moving plate 45 and the lower moving plate 46 are connected to an upper connecting plate 45a and a lower connecting plate 46a at their tip ends, respectively, and to a rotating plate 47 via an annular portion 49 at their base ends. A drive plate 48 and annular portion 49 are fixed to a rotation center 47a of the rotating plate 47. The annular portion 49 is formed in an elliptical shape with its longitudinal direction in the Z direction, and its center is fixed to the rotation center 47a of the rotating plate 47. The annular portion 49 has an upper elongated hole 51 above the rotation center 47a, and a circular upper cam 52 provided at the base of the upper moving plate 45 is rotatably engaged with the upper elongated hole 51. The annular portion 49 also has a lower elongated hole 53 below the rotation center 47a, and a circular lower cam 54 provided at the base of the lower moving plate 46 is rotatably engaged with the lower elongated hole 53.

[0030] The drive plate 48 includes an arc-shaped plate portion 48a and an elongated plate portion 48b extending linearly radially from the center of the inner diameter side of the arc-shaped plate portion 48a, with an upper step portion 48c and a lower step portion 48d formed where the arc-shaped plate portion 48a and the elongated plate portion 48b are connected. The drive plate 48 has a distal end of the elongated plate portion 48b fixed to the rotation center 47a of the rotating plate 47, and the arc-shaped plate portion 48a connected to a drive unit 50, with the drive force from the drive unit 50 being applied to the arc-shaped plate portion 48a. In addition, the drive plate 48 has an upper elongated hole 51 in an annular portion 49 disposed above the elongated plate portion 48b and a lower elongated hole 53 in the annular portion 49 disposed below the elongated plate portion 48b, with the elongated plate portion 48b being disposed between the upper moving plate 45 and the lower moving plate 46.

[0031] The driving force from the driving unit 50 pushes the arc-shaped plate portion 48a upward with the rotation center 47a as the rotation axis of the driving plate 48, causing the long plate portion 48b and the annular portion 49 to rotate counterclockwise around the rotation center 47a of the rotating plate 47. The driving force from the driving unit 50 pushes the arc-shaped plate portion 48a downward with the rotation center 47a as the rotation axis of the driving plate 48, causing the long plate portion 48b and the annular portion 49 to rotate clockwise around the rotation center 47a of the rotating plate 47.

[0032] Here, the reference position of drive plate 48 is defined as a state in which the longitudinal direction of elongated plate portion 48b of drive plate 48 is aligned with reference line O that passes through rotation center 47a and extends in the Y direction. The following describes the configuration when drive plate 48 is in the reference position. When drive plate 48 is in the reference position, the longitudinal direction of annular portion 49 extends in the Z direction, which is perpendicular to the Y direction, and upper elongated hole 51 of annular portion 49 is positioned above rotation center 47a, while lower elongated hole 53 of annular portion 49 is positioned below rotation center 47a. As a result, upper cam 52 engaged with upper elongated hole 51 of annular portion 49 and lower cam 54 engaged with lower elongated hole 53 of annular portion 49 are aligned in a straight line with rotation center 47a in the Z direction.

[0033] 5, when the driving plate 48 is in the reference position, the first roller 43 and the second roller 44 are arranged in a straight line facing each other in the Z direction, and the distances in the Y direction to the edge surface 27a of the wafer 27 are the same. Furthermore, when the driving plate 48 is in the reference position, the distance in the Z direction (thickness direction of the wafer 27) from the outer circumferential surface of the first roller 43, on which the polishing tape 33 is stretched, to the outer circumferential surface of the second roller 44 is set to be shorter than the thickness of the wafer 27. In other words, the entire edge surface of the wafer 27 cannot be positioned in the gap between the first roller 43 and the second roller 44, which are moved with the polishing tape 33 stretched therebetween, and the first roller 43 and the second roller 44 cannot sandwich the wafer 27 in the thickness direction.

[0034] A back pad 55 is provided between the first roller 43 and the second roller 44 to support the polishing tape 33 that is transported between the first roller 43 and the second roller 44. The back pad 55 is made of metal or resin and has four faces with a substantially rectangular cross section, with the polishing tape 33 contacting a surface 55b of one of the four faces. In this case, the back pad 55 provided between the first roller 43 and the second roller 44 is positioned on a reference line O that indicates a reference in the height direction (Z direction) of the roller group 24.

[0035] As the first roller 43 and the second roller 44 move in a direction approaching the edge surface 27a of the wafer 27, the back pad 55 presses the polishing tape 33 transferred between the first roller 43 and the second roller 44 against the edge surface 27a of the wafer 27 with the surface 55b, thereby applying a surface pressure to the edge surface 27a of the wafer 27. Any of the four surfaces of the back pad 55 can be used as the surface 55b. For example, after a predetermined period of time has elapsed, the back pad 55 may be rotated approximately 90 degrees around the axis 55a of the back pad 55, and a surface other than the surface that was in contact with the polishing tape 33 may be used as the surface 55b.

[0036] The first roller 43 and the second roller 44 are connected to elliptical annular linking portions 56a, 56b having elongated holes 57. The linking portions 56a, 56b are disposed opposite each other in the X direction, and when the drive plate 48 is in the reference position, the longitudinal direction of the elongated holes 57 is disposed along the Z direction. The elongated holes 57 of the linking portions 56a, 56b according to this embodiment are selected to have a length slightly greater than the thickness of the wafer 27. The linking portion 56a is positioned such that one ends of the first roller 43, the second roller 44, and the back pad 55 are inserted into the elongated hole 57, and the frame portions of the elongated hole 57 are fitted into grooves formed in the outer peripheral surfaces of one end of the first roller 43, the second roller 44, and the back pad 55, respectively. The linking portion 56b is positioned by inserting the other ends of the first roller 43, the second roller 44, and the back pad 55 into the long hole 57, and fitting the frame portion of the long hole 57 into grooves formed on the outer peripheral surfaces of the other ends of the first roller 43, the second roller 44, and the back pad 55, respectively.

[0037] In the linking portions 56a, 56b, the first roller 43, the second roller 44, and the back pad 55 are rotatably provided within an elongated hole 57, with the back pad 55 positioned in the middle of the elongated hole 57 and the first roller 43 and the second roller 44 being provided to be movable along the longitudinal direction within the elongated hole 57. When the first roller 43 and the second roller 44 independently move toward or away from the edge surface 27a of the wafer 27 (Y direction), the linking portions 56a, 56b guide the first roller 43 and the second roller 44 along the elongated hole 57, and the elongated hole 57 restricts the amount of movement of the first roller 43 and the second roller 44 in the Y direction.

[0038] The operation of the above configuration will be described. As shown in Fig. 1, in the wafer processing system 10, the transfer machine 18 unloads one wafer 27 from one of the four cassette stands 11 to 14 and loads the wafer 27 into the wafer edge face inspection device 16. The shape of the edge face 27a of the wafer 27 loaded into the wafer edge face inspection device 16 is inspected by the wafer edge face inspection device 16. Data on the inspected edge face shape is sent to the wafer edge face polishing device 17. Then, after the inspection of the wafer 27 by the wafer edge face inspection device 16 is completed, the transfer machine 18 unloads the wafer 27 from the wafer edge face inspection device 16 and loads it into the wafer edge face polishing device 17.

[0039] The wafer edge polishing device 17 acquires data on the shape of the edge surface 27a of the wafer 27 inspected by the wafer edge surface inspection device 16, and based on that data, determines the height position of the wafer 27 during polishing, the contact and separation states of the first roller 43 and the second roller 44, and other factors in order to form the edge surface 27a of the wafer 27 into an optimal shape. Here, the optimal shape of the edge surface 27a of the wafer 27 is, for example, an R-shape that finishes the edge surface 27a of the wafer 27 into an arc shape that is symmetrical in the thickness direction of the wafer 27. Note that the optimal shape of the edge surface 27a of the wafer 27 is not limited to an R-shape, and may be an asymmetric shape that is asymmetrical in the thickness direction.

[0040] The contact / separation states of the first roller 43 and the second roller 44 can be divided into at least three types: a first polishing operation, a second polishing operation, and a third polishing operation. In the first polishing operation, as shown in FIG. 5 , the drive plate 48 is set to a reference position, and the first roller 43 and the second roller 44 are arranged in a straight line in the Z direction with the drive plate 48 positioned close to the back pad 55. The polishing tape 33 is continuously transported while stretched along the Z direction. Then, in the first polishing operation, the base plate 32 moves in this state toward the edge surface 27a of the wafer 27, thereby moving the first roller 43 and the second roller 44 together with the base plate 32 toward the edge surface 27a of the wafer 27. As a result, in the first polishing operation, the polishing tape 33 transported between the first roller 43 and the second roller 44 is pressed against the edge surface 27a of the wafer 27, thereby polishing the edge surface 27a of the wafer 27 vertically along the Z direction.

[0041] 6 and 7, in the second polishing operation, the upper sides of the linkage parts 56a and 56b are tilted toward the wafer 27 around the back pad 55. As a result, in the second polishing operation, the first roller 43 moves in a direction away from the back pad 55 along the elongated holes 57 of the linkage parts 56a and 56b, thereby moving the first roller 43 in a direction approaching the edge surface 27a of the wafer 27, and the second roller 44 moves in a direction away from the back pad 55 along the elongated holes 57 of the linkage parts 56a and 56b, thereby moving the second roller 44 in a direction away from the edge surface 27a of the wafer 27. Furthermore, since the distance between the first roller 43 and the second roller 44 in the thickness direction of the wafer 27 during the second polishing operation is the same as the distance between the first roller 43 and the second roller 44 in the thickness direction of the wafer 27 during the first polishing operation, the gap between the first roller 43 and the second roller 44 in the thickness direction of the wafer 27 can be maintained narrow without widening.

[0042] As a result, in the second polishing operation, the polishing tape 33, which is continuously transported while being stretched between the first roller 43 and the second roller 44, is tilted downward so as to gradually move away from the edge surface 27a of the wafer 27. In the second polishing operation, the base plate 32 moves in a direction approaching the edge surface 27a of the wafer 27 while maintaining this state, thereby moving the first roller 43 and the second roller 44 together with the base plate 32 in a direction approaching the edge surface 27a of the wafer 27. As a result, in the second polishing operation, the polishing tape 33, which is continuously transported while being tilted between the first roller 43 and the second roller 44, is pressed against the periphery of the upper corner of the edge surface 27a of the rotating wafer 27, thereby polishing the periphery of the upper corner of the edge surface 27a of the wafer 27.

[0043] 8 and 9, in the third polishing operation, the lower sides of the linkage parts 56a and 56b are tilted toward the wafer 27 around the back pad 55. As a result, in the third polishing operation, the second roller 44 moves in a direction away from the back pad 55 along the elongated holes 57 of the linkage parts 56a and 56b, thereby moving the second roller 44 in a direction approaching the edge surface 27a of the wafer 27, and the first roller 43 moves in a direction away from the back pad 55 along the elongated holes 57 of the linkage parts 56a and 56b, thereby moving the first roller 43 in a direction away from the edge surface 27a of the wafer 27. Furthermore, since the distance between the first roller 43 and the second roller 44 in the thickness direction of the wafer 27 during the third polishing operation is the same as the distance between the first roller 43 and the second roller 44 in the thickness direction of the wafer 27 during the first polishing operation, the gap between the first roller 43 and the second roller 44 in the thickness direction of the wafer 27 can be maintained narrow without widening.

[0044] As a result, in the third polishing operation, the polishing tape 33, which is continuously transported while being stretched between the first roller 43 and the second roller 44, is tilted upward so as to gradually move away from the edge surface 27a of the wafer 27. In the third polishing operation, the base plate 32 moves in a direction approaching the edge surface 27a of the wafer 27 while maintaining this state, thereby moving the first roller 43 and the second roller 44 together with the base plate 32 in a direction approaching the edge surface 27a of the wafer 27. As a result, in the third polishing operation, the polishing tape 33, which is continuously transported while being tilted between the first roller 43 and the second roller 44, is pressed against the periphery of the lower corner of the edge surface 27a of the wafer 27, thereby polishing the periphery of the lower corner of the edge surface 27a of the wafer 27.

[0045] In addition to this configuration, the wafer edge polishing device 17 is configured so that when performing the first polishing operation, the second polishing operation, and the third polishing operation, the wafer 27 is moved appropriately in the central axis direction (Z direction) via the wafer rotation mechanism 22 by the wafer lifting mechanism 23, and the position at which the edge 27a of the wafer 27 slides against the polishing tape 33 can be adjusted.

[0046] The order of the polishing operations is determined according to the shape of the end face 27a of the wafer 27. The order of the polishing operations may be, for example, a first polishing operation, a second polishing operation, and a third polishing operation. The order of the polishing operations is not limited to the above-described order, and for example, the second polishing operation and the third polishing operation may be reversed. When performing such a first polishing operation, a second polishing operation, and / or a third polishing operation, the wafer 27 is rotated in the circumferential direction by the wafer rotation mechanism 22 as appropriate, and the end face 27a of the wafer 27 is polished with the polishing tape 33 while changing the circumferential position at which the polishing tape 33, transported between the first roller 43 and the second roller 44, comes into sliding contact with the end face 27a of the wafer 27.

[0047] In the wafer edge polishing device 17, based on the inspection results of the shape of the edge 27a of the wafer 27 obtained by the wafer edge inspection device 16, not only the inclination angle of the polishing tape 33 but also the height position of the wafer 27 is determined for each wafer 27, and the above-mentioned first polishing operation, second polishing operation and / or third polishing operation is started.

[0048] 5, in the first polishing operation, the wafer 27 is moved in the central axis direction (Z direction) by the wafer lifting mechanism 23 so that the intermediate position 27b of the thickness of the wafer 27 is at the same height as a reference line O passing through a back pad 55 provided at the intermediate position between the first roller 43 and the second roller 44. Then, in the first polishing operation, the drive plate 48 is set to the reference position, and the first roller 43 and the second roller 44 are aligned in the Z direction. Then, in the first polishing operation, the base plate 32 is moved in a direction approaching the end face 27a of the wafer 27. As a result, in the first polishing operation, the polishing tape 33 being transferred perpendicularly to the first roller 43 and the second roller 44 is pressed against the end face 27a of the wafer 27 supported by the wafer rotation mechanism 22, and the end face 27a of the wafer 27 can be polished so that its shape is a vertical plane along the Z direction.

[0049] In the second polishing operation, as shown in FIG. 7, the wafer 27 is lowered in the central axis direction (Z direction) by the wafer lifting mechanism 23 so that the intermediate position 27b of the thickness of the wafer 27 is at a height position below the reference line O passing through the back pad 55. Then, in the second polishing operation, as shown in FIG. 6, the drive plate 48 is rotated counterclockwise, thereby rotating the rotating plate 47 and the annular portion 49 counterclockwise. The upper cam 52 provided in the upper elongated hole 51 of the annular portion 49 is pushed in a direction approaching the end surface 27a of the wafer 27 in conjunction with the annular portion 49 rotating counterclockwise. As a result, the first roller 43 provided on the tip side of the upper movable plate 45 moves in a direction approaching the end surface 27a of the wafer 27 in conjunction with the upper movable plate 45. On the other hand, when the annular portion 49 of the lower moving plate 46 rotates counterclockwise, the lower cam 54 provided in the lower elongated hole 53 of the annular portion 49 is pulled in a direction away from the end surface 27a of the wafer 27 in conjunction with the annular portion 49 rotating counterclockwise. The second roller 44 provided on the tip side of the lower moving plate 46 moves in a direction away from the end surface 27a of the wafer 27 in conjunction with the lower moving plate 46.

[0050] 7, the polishing tape 33, which is stretched between the first roller 43 and the second roller 44 and continuously transported, is tilted such that the upper side approaches the edge surface 27a of the wafer 27 and the lower side moves away from it. At this time, the back pad 55, which is fixed to the rotation center of the linkage parts 56a and 56b that are rotating counterclockwise, rotates counterclockwise around the axis 55a together with the linkage parts 56a and 56b in accordance with the tilt of the polishing tape 33, and maintains a state in which the surface part 55b is pressed against the surface of the polishing tape 33. As a result, the back pad 55 receives the load applied to the polishing tape 33 from the edge surface 27a of the wafer 27 when the polishing tape 33 is pressed against the edge surface 27a of the wafer 27.

[0051] In the second polishing operation, the intermediate position 27b of the thickness of the wafer 27 is set at a height position below the reference line O passing through the back pad 55, and the polishing tape 33 continuously transported between the first roller 43 and the second roller 44 is tilted so that the upper side approaches the edge surface 27a of the wafer 27 and the lower side moves away from the edge surface 27a of the wafer 27. In this state, in the second polishing operation, the polishing tape 33 continuously transported in an inclined state between the first roller 43 and the second roller 44 can be pressed against the upper corners of the edge surface 27a of the wafer 27 supported by the wafer rotation mechanism 22, and the upper corners of the edge surface of the wafer 27 can be polished to have a curved R-shape.

[0052] In the third polishing operation, as shown in FIG. 9, the wafer 27 is raised in the central axis direction (Z direction) by the wafer lifting mechanism 23 so that the intermediate position 27b of the thickness of the wafer 27 is at a height position above a reference line O passing through the back pad 55. Then, in the third polishing operation, as shown in FIG. 8, the drive plate 48 is rotated clockwise, thereby rotating the rotating plate 47 and the annular member 49 clockwise. The upper cam 52 of the upper moving plate 45, which is provided in the upper elongated hole 51 of the annular member 49, moves in a direction away from the end surface 27a of the wafer 27 in conjunction with the annular member 49 rotating clockwise. Meanwhile, when the annular member 49 rotates clockwise, the lower cam 54 of the lower moving plate 46, which is provided in the lower elongated hole 53 of the annular member 49, moves in a direction toward the end surface 27a of the wafer 27 in conjunction with the annular member 49 rotating clockwise. The second roller 44 provided on the tip side of the lower moving plate 46 moves in conjunction with the lower moving plate 46 in a direction approaching the end surface 27 a of the wafer 27 .

[0053] 9, the polishing tape 33, which is stretched between the first roller 43 and the second roller 44 and continuously transported, is tilted so that the lower side approaches the edge surface 27a of the wafer 27 and the upper side moves away from it. At this time, the back pad 55, which is fixed to the rotation center of the linkage parts 56a and 56b that are rotating clockwise, rotates around the axis 55a together with the linkage parts 56a and 56b in accordance with the tilt of the polishing tape 33, and maintains a state in which the surface part 55b is pressed against the surface of the polishing tape 33. As a result, the back pad 55 withstands the load applied to the polishing tape 33 from the edge surface 27a of the wafer 27 when the polishing tape 33 is pressed against the edge surface 27a of the wafer 27.

[0054] In the third polishing operation, the intermediate position 27b of the thickness of the wafer 27 is set at a height position above the reference line O passing through the back pad 55, and the polishing tape 33 continuously transported between the first roller 43 and the second roller 44 is tilted so that the lower side approaches the edge surface 27a of the wafer 27 and the upper side moves away from the edge surface 27a of the wafer 27. In this state, in the third polishing operation, the polishing tape 33 continuously transported in an inclined state between the first roller 43 and the second roller 44 can be pressed against the lower corners of the edge surface 27a of the wafer 27 supported by the wafer rotation mechanism 22, and the lower corners of the edge surface of the wafer 27 can be polished to have a curved R-shape.

[0055] In the above configuration, the wafer edge polishing apparatus 17 supports the wafer 27 by the wafer rotation mechanism 22, moves both or either one of the first roller 43 and the second roller 44 by the roller movement mechanism 25 in a direction approaching the edge 27a of the wafer 27 supported by the wafer rotation mechanism 22, and polishes the edge 27a of the wafer 27 by the polishing tape 33 continuously transported between the first roller 43 and the second roller 44. At this time, the wafer edge polishing apparatus 17 uses the wafer lifting mechanism 23 to lift and lower the wafer 27 supported by the wafer rotation mechanism 22 in the central axis direction, thereby changing the position of the edge 27a of the wafer 27 with which the polishing tape 33 contacts in the thickness direction of the wafer 27.

[0056] In this way, in the wafer edge surface polishing apparatus 17, the first roller 43 and the second roller 44 each move independently in a direction approaching the edge surface 27a of the wafer 27, thereby changing the inclination angle of the polishing tape 33. In addition, the wafer 27 can be moved in the direction of the central axis by the wafer lifting mechanism 23. Therefore, the position where the polishing tape 33 contacts the edge surface 27a of the wafer 27 can be changed by adjusting the inclination angle of the polishing tape 33, and the position where the polishing tape 33 contacts the edge surface 27a of the wafer 27 can also be changed by changing the height position of the edge surface 27a of the wafer 27 along the central axis direction. Therefore, even if the entire end surface of the wafer 27 is not necessarily positioned between the first roller 43 and the second roller 44 on which the polishing tape 33 is transported, the entire end surface of the wafer 27 can be polished by appropriately changing the height position of the end surface 27a of the wafer 27.Therefore, even if the gap between the first roller 43 and the second roller 44 in the thickness direction of the wafer 27 is made smaller than before, the end surface 27a of the wafer 27 can be formed into an appropriate shape.

[0057] In the above-described embodiment, the first polishing operation involves moving the wafer 27 in the central axis direction (Z direction) by the wafer lifting mechanism 23 so that the intermediate position 27b of the wafer 27 is at the same height as a reference line O passing through a back pad 55 provided at a midpoint between the first roller 43 and the second roller 44, and polishing the end surface 27a of the wafer 27 with the polishing tape 33 stretched in the thickness direction of the wafer 27. However, the present invention is not limited to this. For example, the first polishing operation may involve using the wafer lifting mechanism 23 to move the intermediate position 27b of the wafer 27 to a height position below the reference line O passing through the back pad 55, as shown in FIG. 7, or to move the intermediate position 27b of the wafer 27 to a height position above the reference line O passing through the back pad 55, as shown in FIG. 9 (FIG. 9), and polishing the end surface 27a of the wafer 27 with the polishing tape 33 stretched in the thickness direction of the wafer 27.

[0058] Furthermore, in the above-described embodiment, the first polishing operation, the second polishing operation, and the third polishing operation are clearly separated. However, the present invention is not limited to this. For example, while the polishing tape 33 is kept in sliding contact with the end surface 27a of the wafer 27, the height position of the wafer 27 and the inclination angle of the polishing tape 33 may be continuously changed so as to gradually switch between states such as from the first polishing operation state to the second polishing operation state, from the second polishing operation state to the first polishing operation state, from the first polishing operation state to the third polishing operation state, and from the third polishing operation state to the first polishing operation state, etc.

[0059] Furthermore, the back pad 55 is not limited to one having a rectangular cross section, and for example, a plate-shaped back pad 58 may be used as shown in Fig. 10. As shown in Fig. 10, the plate-shaped back pad 58 is provided between the first roller 43 and the second roller 44. The roller moving mechanism 25 shown in Fig. 10 includes a pair of the first roller 43 and the second roller 44, a pair of the first roller 43a and the second roller 44a, and annular portions 59, 59a.

[0060] The annular portion 59 is an elliptical annular body having a longitudinal direction, and the first roller 43 and the second roller 44 are provided at both ends in the longitudinal direction. The annular portion 59 has a rotation axis 60 at its longitudinal center, and is supported by the base plate 32 (FIG. 3) so as to be rotatable clockwise or counterclockwise about the rotation axis 60 in a YZ plane including the Y and Z directions. The annular portion 59a, like the annular portion 59, is also an elliptical annular body having a longitudinal direction, and the first roller 43a and the second roller 44a are provided at both ends in the longitudinal direction. The annular portion 59a has a rotation axis 60a at its longitudinal center, and is supported by the base plate 32 (FIG. 3) so as to be rotatable clockwise or counterclockwise about the rotation axis 60a in a YZ plane including the Y and Z directions.

[0061] The annular portions 59, 59a are rotated counterclockwise or clockwise about the rotation shafts 60, 60a by a drive unit (not shown), which independently moves the first rollers 43, 43a and the second rollers 44, 44a toward or away from the end face 27a of the wafer 27. Specifically, when the annular portions 59, 59a rotate counterclockwise about the rotation shafts 60, 60a, the first rollers 43, 43a move toward the end face 27a of the wafer 27, and the second rollers 44, 44a move away from the end face 27a of the wafer 27. When the annular portions 59, 59a rotate clockwise about the rotation shafts 60, 60a, the first rollers 43, 43a move away from the end face 27a of the wafer 27, and the second rollers 44, 44a move toward the end face 27a of the wafer 27. As a result, similar to the embodiment described above, the polishing tape 33, which is stretched between the first roller 43 and the second roller 44 and continuously transported, can be positioned vertically along the Z direction or tilted at a predetermined angle. In this case, the back pad 58 tilts in the same manner as the tilt of the annular portion 59, and supports the polishing tape 33 from behind.

[0062] Furthermore, in the above-described embodiment, the wafer edge polishing apparatus 17 is described as polishing the edge surface 27a of the wafer 27 using one type of polishing tape 33, but the present invention is not limited to this. For example, a wafer edge polishing apparatus 62 may be applied that polishes the edge surface 27a of the wafer 27 by appropriately switching between multiple types of polishing tapes with different roughnesses, such as two or three types with different roughnesses.

[0063] 11, a wafer edge polishing device 62 is provided with a tape switching mechanism 65 that switches between two types of polishing tape with different roughness: a first polishing tape 63 and a second polishing tape 64. The first polishing tape 63 has a predetermined grain size of abrasive, while the second polishing tape 64 has a different grain size of abrasive than the first polishing tape 63;

[0064] In addition to the tape switching mechanism 65, the wafer edge polishing apparatus 62 also includes a first roller group 66, a second roller group 67 provided next to the first roller group 66, a first tape transfer mechanism 68, and a second tape transfer mechanism 69. Although not shown in Fig. 11, similar to the above-described embodiment, the apparatus also includes a wafer rotation mechanism 22, a wafer lifting mechanism 23, a roller movement mechanism 25, etc.

[0065] The first roller group 66 has a first roller 66a and a second roller 66b arranged opposite each other in the thickness direction (Z direction) of the wafer 27, and is configured so that the first polishing tape 63 transferred from a first tape transfer mechanism 68 is continuously transferred in a state in which it is stretched between the first roller 66a and the second roller 66b. The second roller group 67 has a third roller 67a and a fourth roller 67b arranged opposite each other in the thickness direction (Z direction) of the wafer 27, and is configured so that the second polishing tape 64 transferred from a second tape transfer mechanism 69 is continuously transferred in a state in which it is stretched between the third roller 67a and the fourth roller 67b. In this embodiment, the first polishing tape 63 and the second polishing tape 64 are arranged side by side in the direction of the rotation axes of the first roller 66a, the second roller 66b, the third roller 67a, and the fourth roller 67b.

[0066] The tape switching mechanism 65 is configured to be able to move, for example, a base plate 32 (FIG. 3) on which a first roller group 66 and a first tape transfer mechanism 68, and a second roller group 67 and a second tape transfer mechanism 69 are provided, in the tangential direction (X direction) of the end surface 27a of the wafer 27 on the XY plane. The tape switching mechanism 65 relatively moves the base plate 32 in the tangential direction (X direction) of the end surface 27a of the wafer 27, thereby positioning either the first roller group 66 or the second roller group 67 so as to face the end surface 27a of the wafer 27, and switching the polishing tape that is in sliding contact with the end surface 27a of the wafer 27 to either the first polishing tape 63 or the second polishing tape 64.

[0067] The operation of the first roller group 66 and the second roller group 67 when polishing the end surface 27a of the wafer 27, the adjustment of the inclination angles of the first polishing tape 63 and the second polishing tape, and the lifting and lowering operation of the wafer 27 by the wafer lifting device 23 during the polishing operation are the same as those in the above-mentioned embodiment, and therefore will not be described here. Also, the tape switching mechanism 65 may be configured to move the wafer 27 being rotated by the wafer rotation mechanism 22 in the tangential direction without moving the base plate 32.

[0068] The present invention is not limited to the above-described embodiments, and many modifications can be made by a person skilled in the art within the technical spirit of the present invention. For example, the roller movement mechanism 25 is not limited to the configuration illustrated in FIG. 3, but may have a well-known configuration. Furthermore, the back pads 55, 58 are not limited to being made of metal or resin, but may be made of well-known materials such as carbon, non-ferrous metals, and wood.

[0069] 10, a heat sink, heat dissipation fins, heat dissipation sheet, or other heat dissipation member may be provided on the back surface opposite the pad side that contacts the polishing tape 33. The heat sink has multiple fins that absorb heat and dissipate it into the air. Copper or aluminum is preferably used as the heat sink because of its good thermal conductivity.

[0070] Furthermore, in the above-described embodiment, a configuration was described in which the first roller 43a and the second roller 44a are moved toward and away from the end face 27a of the wafer 27 simply by moving the base plate 32 in the direction toward or away from the end face 27a of the wafer 27 (Y direction). However, the present invention is not limited to this. For example, as shown in FIG. 12, a base plate 32 having a load sensor 76 such as a load sensor may be attached to the base plate support portion 32a via a linear guide (not shown), and the base plate support portion 32a and the base plate 32 may be moved toward or away from the end face 27a of the wafer 27 (Y direction) to move the first roller 43a and the second roller 44a toward and away from the end face 27a of the wafer 27.

[0071] In this case, as shown in FIG. 12 , a long plate-like or long rod-like sensor support portion 75 is provided between the upper movable plate 45 and the lower movable plate 46, running parallel to the longitudinal direction of the upper movable plate 45 and the lower movable plate 46. Elliptical annular linkage portions 56a and 56b with long holes 57 are provided at the tip of the sensor support portion 75, facing each other in the X direction, and the tip of the sensor support portion 75 is rotatably provided at the center of the linkage portions 56a and 56b. The load sensor 76 detects the load acting on the polishing tape 33 from the wafer 27 when the polishing tape 33, stretched between the first roller 43a and the second roller 44a, is brought into contact with the edge surface 27a of the wafer 27. A linear guide provided on the base plate 32 moves the base plate 32 in the direction Y2 away from the wafer 27 based on the detection result of the load sensor 76, thereby adjusting the contact force of the polishing tape 33 with the wafer 27.

[0072] 12 differs from the configuration of the above-described embodiment in that a first linkage roller 71 is provided at the tip of the upper moving plate 45, and a second linkage roller 72 is provided at the tip of the lower moving plate 46. The first linkage roller 71 and the second linkage roller 72 are hung between the elongated holes 57 of the linkage parts 56a and 56b that are arranged opposite each other in the X direction. A first roller 43a is hung at the upper end between the elongated holes 57 of the linkage parts 56a and 56b, and a second roller 44a is hung at the lower end. The polishing tape 33 is hung between the first roller 43a and the second roller 44a that are rotatably provided at the ends of the linkage parts 56a and 56b, respectively, and the polishing tape 33 is supported by a back pad 55 provided between the first roller 43a and the second roller 44a.

[0073] As described above, in this embodiment, the first roller 43a and the second roller 44a are not provided on the upper movable plate 45 and the lower movable plate 46, but as in the above-described embodiment, by moving the upper movable plate 45 and the lower movable plate 46 in a direction toward or away from the edge surface 27a of the wafer 27, the first roller 43a and the second roller 44a can be independently moved toward or away from the edge surface 27a of the wafer 27. This allows the polishing tape 33, which is stretched between the first roller 43a and the second roller 44a and continuously transported, to be tilted, etc.

[0074] In the above-described configuration, in a wafer edge surface polishing apparatus according to another embodiment, the base plate support portion 32a and the base plate 32, which is attached to the base plate support portion 32a via a linear guide, are moved in a direction Y1 toward the edge surface 27a of the wafer 27. As a result, the wafer edge surface polishing apparatus brings the polishing tape 33, which is continuously transported by the first roller 43a and the second roller 44a, into contact with the edge surface 27a of the wafer 27 supported by the wafer rotation mechanism 22. At this time, when the polishing tape 33, which is continuously transported while stretched between the first roller 43a and the second roller 44a, is brought into contact with the edge surface 27a of the wafer 27, the wafer edge surface polishing apparatus can detect the load that the polishing tape 33 receives from the wafer 27 using the load sensor 76.

[0075] The wafer edge surface polishing apparatus moves the base plate 32 in the direction Y2 away from the wafer 27 by driving the linear guide based on the load detected by the load sensor 76, thereby adjusting the contact force of the polishing tape 33 on the edge surface 27a of the wafer 27. This prevents the polishing tape 33 from being pressed too hard against the edge surface 27a of the wafer 27, and allows the polishing tape 33 to be pressed against the edge surface 27a of the wafer 27 with an optimal contact force, thereby polishing the edge surface 27a more accurately. [Explanation of symbols]

[0076] 16 Wafer edge inspection equipment 17,62 Wafer edge polishing equipment 22 Wafer rotation mechanism 23 Wafer lifting mechanism 25 Roller movement mechanism 26 Tape transport mechanism 27 wafers 27a End face 29 Rotational Axis 43,43a First roller 44,44a Second roller 63 First Polishing Tape 64 Second Polishing Tape 65 Tape switching mechanism 68 First tape transport mechanism 69 Second tape transport mechanism

Claims

1. a wafer rotation mechanism that supports the wafer and rotates the wafer in a circumferential direction around a central axis of the wafer; a wafer lifting mechanism that lifts and lowers the wafer supported by the wafer rotation mechanism in a central axis direction; a first roller disposed radially outward of the wafer supported by the wafer rotation mechanism; a second roller disposed radially outward of the wafer supported by the wafer rotation mechanism and facing the first roller in the thickness direction of the wafer; a tape transfer mechanism that stretches the polishing tape wound around the first roller and the second roller between the first roller and the second roller and transfers the polishing tape between the first roller and the second roller; a roller moving mechanism that moves the first roller and the second roller independently in a direction toward and away from the edge surface of the wafer, and moves the polishing tape in a direction toward and away from the edge surface of the wafer; Equipped with The roller moving mechanism includes: moving both or either one of the first roller and the second roller in a direction approaching the edge of the wafer supported by the wafer rotation mechanism, and polishing the edge of the wafer with the polishing tape being transferred between the first roller and the second roller; The wafer lifting mechanism includes: The wafer edge polishing apparatus changes the position of the wafer edge that comes into contact with the polishing tape in the thickness direction of the wafer by raising and lowering the wafer.

2. a back pad having a surface portion is provided between the first roller and the second roller; 2. The wafer edge polishing apparatus of claim 1, wherein the back pad supports the polishing tape transported between the first roller and the second roller with the surface portion and presses the polishing tape supported by the surface portion against the edge surface of the wafer.

3. The wafer lifting mechanism includes:

2. The wafer edge polishing apparatus according to claim 1, wherein the height position of the wafer is determined based on an inspection result of the shape of the edge of the wafer obtained by a wafer edge inspection apparatus that inspects the shape of the edge of the wafer.

4. the tape transport mechanism is provided as a first tape transport mechanism, the polishing tape is provided as a first polishing tape, and a third roller disposed radially outward of the wafer supported by the wafer rotation mechanism; a fourth roller disposed radially outward of the wafer supported by the wafer rotation mechanism and facing the third roller in the thickness direction of the wafer; a second tape transport mechanism that winds a second polishing tape having a different roughness from the first polishing tape around the third roller and the fourth roller, stretches the second polishing tape between the third roller and the fourth roller, and transports the second polishing tape between the third roller and the fourth roller; a tape switching mechanism that moves a first roller group consisting of the first roller and the second roller and a second roller group consisting of the third roller and the fourth roller relative to the wafer, and brings the first polishing tape or the second polishing tape into sliding contact with the edge surface of the wafer; The wafer edge polishing apparatus according to claim 1 , comprising:

5. a base plate on which the tape transfer mechanism and the roller movement mechanism are provided; a load sensor provided on the base plate for detecting a load applied from the wafer to the polishing tape when the polishing tape is brought into contact with the edge surface of the wafer; Equipped with The base plate is 2. The wafer edge polishing apparatus according to claim 1, wherein the apparatus moves in a direction away from the wafer based on the load detected by the load sensor, and adjusts the contact force of the polishing tape on the edge of the wafer.

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