WO2019176413A1

WO2019176413A1 - Polishing device

Info

Publication number: WO2019176413A1
Application number: PCT/JP2019/004867
Authority: WO
Inventors: 峯杰杜; 誠柏木; 吉田　篤史; 道義山下
Original assignee: 株式会社荏原製作所
Priority date: 2018-03-12
Filing date: 2019-02-12
Publication date: 2019-09-19
Also published as: JP2019155519A; TW201938320A

Abstract

The present invention relates to a polishing device in which a polishing tape is pressed against an edge portion of a substrate to polish the edge portion. The polishing device comprises a substrate holding portion (1) that holds and rotates a substrate W, a pressing member (11) that presses the polishing surface of a polishing tape (7) against the edge portion of the substrate W, and a pressing roller mechanism (50) disposed on the polishing surface side of the polishing tape (7). The pressure roller mechanism (50) includes at least one pressure roller unit (51) having a pressure roller (52) in contact with the polishing surface of the polishing tape (7), a biasing means (54) for applying, to the pressing roller (11), a biasing force for pressing the surface of the polishing tape (7) on the side opposite to the polishing surface against the pressing member (11), and a biasing force adjustment mechanism (53) that adjusts the biasing force of the biasing means (54).

Description

Polishing equipment

The present invention relates to a polishing apparatus for polishing a peripheral portion of a substrate such as a semiconductor wafer, and more particularly to a polishing apparatus for pressing an abrasive tape against an edge portion of a substrate to polish the edge portion.

In recent years, management of the surface state of a substrate has attracted attention from the viewpoint of improving the yield in the manufacture of semiconductor devices. In the manufacturing process of a semiconductor device, various materials are formed on a silicon wafer. For this reason, an unnecessary film | membrane and surface roughness are formed in the peripheral part of a board | substrate. In recent years, a method of conveying a substrate while holding only the peripheral edge of the substrate with an arm has become common. Under such a background, an unnecessary film remaining on the peripheral edge peels off during various steps and adheres to the device formed on the substrate, thereby reducing the yield. Therefore, in order to remove an unnecessary film formed on the peripheral portion of the substrate, the peripheral portion of the substrate is polished using a polishing apparatus.

This type of polishing apparatus polishes the peripheral portion of the substrate by bringing the polishing surface of the polishing tape into sliding contact with the peripheral portion of the substrate (see, for example, Patent Document 1 and Patent Document 2). Here, in this specification, the peripheral part of a board | substrate is defined as an area | region including the bevel part located in the outermost periphery of a board | substrate, and the top edge part and bottom edge part located in the radial inside of this bevel part.

FIG. 18A and FIG. 18B are enlarged cross-sectional views showing a peripheral portion of a wafer as an example of a substrate. More specifically, FIG. 18A is a cross-sectional view of a so-called straight type wafer, and FIG. 18B is a cross-sectional view of a so-called round type wafer. In the wafer W of FIG. 18A, the bevel portion is the outermost peripheral surface of the wafer W composed of an upper inclined portion (upper bevel portion) P, a lower inclined portion (lower bevel portion) Q, and a side portion (apex) R. (Denoted by B). In the wafer W of FIG. 18B, the bevel portion is a portion (indicated by reference sign B) that forms the outermost peripheral surface of the wafer W and has a curved cross section. The top edge portion is a flat portion E1 that is located radially inward of the bevel portion B. The bottom edge portion is a flat portion E2 that is located on the opposite side of the top edge portion and located radially inward of the bevel portion B. The top edge portion may include a region where a device is formed. In the following description, the top edge portion is simply referred to as an edge portion.

FIG. 19A is a diagram schematically showing a state where a wafer which is an example of a substrate is being polished by a conventional polishing apparatus, and FIG. 19B is a cross-sectional view taken along line EE of FIG. 19A. As shown in FIG. 19A, the polishing tape 107 extends parallel to the tangential direction of the wafer W at a contact point where the polishing tape 107 contacts the edge portion of the wafer W. The lower surface of the polishing tape 107 constitutes a polishing surface for polishing the edge portion of the wafer W.

As illustrated in FIG. 19B, the polishing apparatus holds the wafer W and rotates the wafer stage 102 of the substrate holding unit 101, and the pressing member 111 that presses the polishing tape 107 against the edge portion of the wafer W held on the wafer stage 102. And. The polishing apparatus further includes a take-up reel (not shown) to which one end of the polishing tape 107 is fixed, and a take-up reel (not shown) to which the other end of the polishing tape 107 is fixed. A load that presses the polishing tape 107 against the edge portion of the wafer W is transmitted to the pressing member 111 through the load transmitting member 127. The pressing member 111 has a through hole 111a formed therein. One end of the through hole 111 a opens at the lower surface of the pressing member 111, and the other end of the through hole 111 a is connected to the vacuum line 130. When a vacuum is formed in the through hole 111a in a state where the pressing member 111 is in contact with the upper surface of the polishing tape 107 (that is, the surface opposite to the polishing surface), the upper surface of the polishing tape 107 is held on the lower surface of the pressing member 111. Is done.

When polishing the edge portion of the wafer W with this polishing apparatus, the wafer W held on the substrate holding portion 101 is rotated, and the polishing tape 107 is sent from the unwinding reel to the take-up reel at a constant speed. In this state, the edge portion of the wafer W is polished by pressing the polishing tape 107 against the edge portion of the wafer W by the pressing member 111.

FIG. 20 is a diagram schematically showing an ideal cross section of the edge portion polished by the polishing apparatus. As shown in FIG. 20, when the polishing of the edge portion of the wafer W is completed, it is preferable that a right-angle cross-sectional shape S composed of the vertical plane Pv and the horizontal plane Ph is formed on the edge portion of the wafer W. . The vertical plane Pv extends perpendicular to the upper surface of the wafer W, and the horizontal plane Ph extends parallel to the upper surface of the wafer W.

During the polishing of the wafer W, the pressing member 111 and the polishing tape 107 may be swung in the radial direction of the wafer W (see arrow D in FIG. 19A). By polishing the polishing tape 107 in the radial direction of the wafer W during polishing of the edge portion of the wafer W, the polishing rate of the edge portion of the wafer W can be increased.

JP 2012-213849 A JP 2009-208214 A

However, during polishing of the edge portion of the wafer W, the polishing tape 107 may receive a load in the horizontal direction due to the contact condition between the polishing tape 107 and the edge portion and the shape of the edge portion. When the horizontal load acting on the polishing tape 107 is larger than the force with which the pressing member 111 holds the polishing tape 107 by vacuum suction, the polishing tape 107 may be displaced with respect to the pressing member 111. In particular, when the edge portion of the wafer W is polished while the polishing tape 107 is swung in the radial direction of the wafer W together with the pressing member 111, a large horizontal load is applied to the polishing tape 107, and the polishing tape 107 is pressed by the pressing member. In some cases, the position was shifted from 111. In this case, the track of the polishing tape 107 fed from the take-up reel to the take-up reel is different from the intended track.

FIG. 21A is a schematic diagram illustrating a state in which the edge portion of the wafer is polished by a polishing tape that is fed while being shifted radially outward or radially inward of the wafer W with respect to the pressing member 111, and FIG. It is a schematic diagram which shows an example of the cross section of the edge part grind | polished with the grinding | polishing tape sent, shifting | deviating with respect to the member 111. FIG. In FIG. 21A, a polishing tape 107 indicated by a solid line represents an abrasive tape sent along an intended trajectory, and an abrasive tape 107 'indicated by a thin one-dot chain line represents an example of an abrasive tape deviated from the intended trajectory. Further, in FIG. 21A, a thick alternate long and short dash line indicates a locus drawn by one point P on the center line of the polishing tape 107 that is sent while being displaced with respect to the pressing member 111. When the polishing tape 107 is sent without deviation from the pressing member 111, the point P moves in parallel with the tangential direction of the wafer W.

As shown in FIG. 21A, the point P on the center line of the polishing tape 107 moves while irregularly shifting radially outward or radially inward with respect to the edge portion of the wafer W. When the edge portion of the wafer is polished by the polishing tape 107 fed in this manner, a right-angle cross-sectional shape S (see FIG. 20) cannot be formed at the edge portion of the wafer W. Specifically, as shown in FIG. 21B, the surface Pv ′ of the cross-sectional shape S ′ formed at the edge portion of the wafer W extends in the vertical direction while inclining radially outward or radially inward of the wafer W. ing. Such poor polishing causes a decrease in the yield of the semiconductor device.

Therefore, an object of the present invention is to provide a polishing apparatus capable of preventing the polishing tape from being displaced with respect to the pressing member during polishing of the edge portion of the substrate.

In one aspect of the present invention, a substrate holding portion that holds and rotates the substrate, a pressing member that presses the polishing surface of the polishing tape against the edge portion of the substrate, and the polishing surface of the polishing tape against the edge portion. A load transmitting member for transmitting a pressing force to the pressing member, and a pressing roller mechanism disposed on the polishing surface side of the polishing tape, wherein the pressing roller mechanism is in contact with the polishing surface of the polishing tape. At least one pressing roller unit having a roller, an urging means for applying an urging force to the pressing member to press the surface opposite to the polishing surface of the polishing tape, and the urging force of the urging means There is provided a polishing apparatus comprising an urging force adjusting mechanism for adjusting the pressure.

In one embodiment, the pressing roller unit has a tilt mechanism capable of adjusting an inclination angle of the pressing roller with respect to a polishing surface of the polishing tape.
In one embodiment, the pressing roller unit includes a bearing that rotatably supports the pressing roller, a bearing block that supports the bearing, and a support block that supports the bearing block via a connection block. The tilt mechanism includes a screw hole that penetrates the connection block, and an angle adjustment screw that is screwed into a screw hole formed in the connection block and contacts the bearing block, and the bearing block includes the connection block. The tilting angle of the pressing roller is changed together with the bearing block by adjusting the screwing amount of the angle adjusting screw with respect to the screw hole.
In one embodiment, the pressing roller unit includes a bearing that rotatably supports the pressing roller, a bearing block that supports the bearing, a support block that supports the bearing block via a connection block, A position adjusting mechanism capable of adjusting the position of the pressing roller in the radial direction.
In one embodiment, the connection block is disposed in a step formed in the support block, and the position adjusting mechanism includes a lateral hole extending from a side surface of the support block to a vertical surface of the step, A position adjusting screw screwed into the horizontal hole, and adjusting the screwing amount of the position adjusting screw with respect to the horizontal hole changes the position of the pressing roller together with the connecting block.

In one embodiment, the pressure roller unit includes a bearing that rotatably supports the pressure roller, a bearing block that supports the bearing, and a support block that supports the bearing block via a connection block. The pressure roller unit further includes a height adjusting member disposed between the connection block and the support block.
In one embodiment, the pressing roller mechanism further includes a base block that supports the pressing roller unit and is disposed below the load transmission member, and the biasing force adjustment mechanism extends through the base block. And a biasing shaft disposed between the base block and the adjusting nut. The screwing shaft is fixed to the load transmitting member, and the adjusting nut is screwed onto the screwing shaft. It is a spring.
In one embodiment, the pressure roller mechanism further includes a separation mechanism for separating the pressure roller from the polishing surface of the polishing tape, and the separation mechanism is a piston cylinder unit fixed to both sides of the base block. Each piston cylinder unit includes a cylinder fixed to the base block, and a piston movable in the cylinder by a fluid supplied to the cylinder, and the pressure of the fluid is the biasing member Is larger than the urging force applied to the pressing roller, and the fluid is supplied to the cylinder, whereby the tip of the piston comes into contact with the load transmitting member and moves the pressing roller together with the base block. .

In one embodiment, the pressure roller mechanism further includes a base block that supports the pressure roller unit and is fixed to the load transmission member, and the biasing force adjustment mechanism includes a nut fixed to the base block; A cap having an inner surface that can be screwed into a thread groove formed on the outer surface of the nut, and the biasing means is a biasing spring disposed between the nut and the cap.
In one embodiment, the pressure roller mechanism further includes a separation mechanism for separating the pressure roller from the polishing surface of the polishing tape, and the separation mechanism is fixed to the pressure roller unit and extends downward. A plate member disposed below the base block, a stopper for fixing a lower end portion of the rod-shaped member to the plate member, and a piston cylinder unit disposed on both sides of the plate member. The cylinder unit includes a cylinder that is fixed to the plate member, and a piston that can be moved in the cylinder by a fluid supplied to the cylinder. The tip of the piston is in contact with the base block by supplying the fluid to the cylinder greater than the urging force applied to the cylinder. To move the press roller downward together with the plate member.

According to the present invention, since the pressing roller presses the upper surface of the polishing tape against the pressing member during polishing of the edge portion of the substrate, the polishing tape is prevented from being displaced from the pressing member. Further, the biasing force with which the pressing roller presses the polishing tape against the pressing member is adjusted to a desired biasing force by the biasing force adjusting mechanism. As a result, the polishing tape can be fed in the tangential direction of the substrate at a predetermined speed while suppressing the deviation of the polishing tape with respect to the pressing member.

FIG. 1 is a plan view schematically showing an embodiment of a polishing apparatus. FIG. 2 is a side view of the polishing apparatus shown in FIG. FIG. 3 is a diagram schematically showing the inside of the polishing head shown in FIG. FIG. 4 is a schematic diagram showing the polishing tape supported by the positioning roller. FIG. 5 is a diagram schematically illustrating a pressing roller mechanism according to an embodiment. FIG. 6 is a perspective view of the pressing roller mechanism shown in FIG. 7 is a cross-sectional view taken along line AA in FIG. FIG. 8 is a view showing a state where the pressing roller is separated from the polishing surface of the polishing tape by the separation mechanism shown in FIG. 9 is a cross-sectional view taken along line BB in FIG. FIG. 10 is a diagram illustrating a state in which the bearing block and the pressing roller are inclined with respect to the horizontal plane. FIG. 11 is a diagram illustrating an example of a height adjusting member that adjusts the height of the pressing roller unit in the vertical direction. 12 is a cross-sectional view taken along the line CC of FIG. FIG. 13 is a diagram showing an example in which the position of the pressing roller in the radial direction of the wafer is changed by the position adjusting mechanism shown in FIG. FIG. 14 is a diagram schematically illustrating a pressing roller mechanism according to another embodiment. FIG. 15 is a view showing a state where the pressing roller is separated from the polishing surface of the polishing tape by the separation mechanism shown in FIG. FIG. 16 is a plan view schematically showing a polishing apparatus according to another embodiment. 17 is a side view of the polishing apparatus shown in FIG. FIG. 18A is a cross-sectional view of a straight wafer. FIG. 18B is a cross-sectional view of a round type wafer. FIG. 19A is a diagram schematically illustrating a state where a wafer which is an example of a substrate is being polished by a conventional polishing apparatus. 19B is a cross-sectional view taken along line EE of FIG. 19A. FIG. 20 is a diagram schematically showing an ideal cross section of the edge portion polished by the polishing apparatus. FIG. 21A is a schematic diagram illustrating a state where the edge portion of the wafer is polished by the polishing tape that is fed while being shifted radially outward or radially inward of the pressing member. FIG. 21B is a schematic diagram illustrating an example of a cross section of the edge portion polished by the polishing tape that is fed while being displaced with respect to the pressing member.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a plan view schematically showing one embodiment of a polishing apparatus, and FIG. 2 is a side view of the polishing apparatus shown in FIG. The polishing apparatus includes a wafer holding unit (substrate holding unit) 1 that holds and rotates a wafer W that is an example of a substrate. The wafer holding unit 1 includes a wafer stage (substrate stage) 2 that can hold the wafer W, and a stage motor 3 that rotates the wafer stage 2 around its axis. The wafer W to be polished is held on the upper surface of the wafer stage 2 by vacuum suction or the like, and is rotated together with the wafer stage 2 by a stage motor 3. The upper surface of the wafer stage 2 functions as a wafer holding surface (substrate holding surface) 2a.

The polishing apparatus has a polishing head 10 having a pressing member 11 that presses the polishing tape 7 against the edge portion of the wafer W. The pressing member 11 is disposed above the wafer stage 2. The polishing tape 7 is a polishing tool for polishing the edge portion of the wafer W. One end of the polishing tape 7 is fixed to the take-up reel 14, and the other end of the polishing tape 7 is fixed to the take-up reel 15. Most of the polishing tape 7 is wound around both the take-up reel 14 and the take-up reel 15, and a part of the polishing tape 7 extends between the take-up reel 14 and the take-up reel 15. The take-up reel 14 and the take-up reel 15 are respectively applied with torques in opposite directions by the

reel motors

17 and 18, whereby tension is applied to the polishing tape 7.

A tape feeder 20 is disposed between the unwinding reel 14 and the take-up reel 15. The polishing tape 7 is fed from the take-up reel 14 to the take-up reel 15 at a constant speed by the tape feeder 20. The polishing tape 7 extending between the take-up reel 14 and the take-up reel 15 is supported by a first guide roller 21 and a second guide roller 22. The axial direction of the first guide roller 21 is parallel to the axial direction of the second guide roller 22. The polishing tape 7 is supported by the first guide roller 21 and the second guide roller 22 so as to extend parallel to the tangential direction of the wafer W. These two

guide rollers

21 and 22 are disposed between the take-up reel 14 and the take-up reel 15.

In one embodiment, the polishing tape 7 may be supported by three or more guide rollers. In this case, two of the three or more guide rollers are used as the first guide roller 21 and the second guide roller 22 described above.

The polishing head 10 includes a pressing member 11 that presses the polishing tape 7 against the edge portion of the wafer W, and two

positioning rollers

23 and 24 that position the polishing tape 7 with respect to the wafer W. The pressing member 11 is positioned between the two

positioning rollers

23 and 24, and the axial directions of the

positioning rollers

23 and 24 are parallel to the axial directions of the first guide roller 21 and the second guide roller 22. The lower surface of the polishing tape 7 extending between the

positioning rollers

23 and 24 constitutes a polishing surface for polishing the edge portion of the wafer W. For example, abrasive grains such as diamond particles are fixed to the polishing surface of the polishing tape 7.

As shown in FIG. 1, the

positioning rollers

23 and 24 are guided by

guide rollers

21 and 22 in a predetermined direction D that is parallel to the wafer holding surface 2 a of the wafer holding unit 2 and perpendicular to the tangential direction of the wafer W. Is also located on the outside. The

positioning rollers

23 and 24 are arranged so that the polishing tape 7 between the

positioning rollers

23 and 24 extends in the tangential direction of the wafer W at the contact point between the edge portion of the wafer W and the polishing tape 7. Therefore, the predetermined direction D is parallel to the radial direction of the wafer W at the contact point between the edge portion of the wafer W and the polishing tape 7. In one embodiment, three or more positioning rollers may be disposed between the first guide roller 21 and the second guide roller 22.

FIG. 3 is a diagram schematically showing the inside of the polishing head 10 shown in FIG. In FIG. 3, only the pressing roller 52 of the pressing roller mechanism described later is shown. As shown in FIG. 3, the polishing head 10 includes the pressing member 11 that presses the polishing tape 7 against the edge portion of the wafer W, an air cylinder 25 that controls the pressing force of the pressing member 11, the pressing member 11, and the air cylinder. And a load transmission member 27 that couples the two. The air cylinder 25 is an actuator that biases the pressing member 11 in a predetermined direction toward the wafer W on the wafer holding unit 1. The air cylinder 25 is configured to urge the pressing member 11 downward toward the edge portion of the wafer W. In the present embodiment, the direction of the pressing member 11 biased by the air cylinder 25 is a direction parallel to the axis of the wafer holding unit 1, that is, a vertical direction. The lower part of the load transmission member 27 is configured as a pressing member holder 27a that detachably holds the pressing member 11. That is, the pressing member 11 is held by the pressing member holder 27 a of the load transmission member 27, and the force generated by the air cylinder 25 is transmitted to the pressing member 11 via the load transmission member 27.

The pressing member 11 has a through hole 11a formed therein. One end of the through hole 11 a is opened at the lower surface of the pressing member 11, and the other end of the through hole 11 a is connected to the vacuum line 30. The vacuum line 30 is provided with a valve (not shown), and a vacuum is formed in the through hole 11a of the pressing member 11 by opening the valve. When a vacuum is formed in the through hole 11 a with the pressing member 11 in contact with the upper surface of the polishing tape 7, the upper surface of the polishing tape 7 is held on the lower surface of the pressing member 11.

The pressing member 11 is fixed to the pressing holder 27a of the load transmitting member 27. The pressing member 11 and the load transmission member 27 constitute an integral structure and are moved together by the air cylinder 25. The load transmission member 27 is movably connected to a linear motion guide 33 extending along the axis of the wafer holding unit 1. The air cylinder 25 and the linear motion guide 33 are fixed to the frame 39. Accordingly, the entire movement direction of the pressing member 11 and the load transmission member 27 is limited to a direction parallel to the axis of the wafer holding unit 1 (that is, the vertical direction).

Although the details of the pressing roller mechanism will be described later, the pressing roller 52 of the pressing roller mechanism is disposed on the polishing surface side of the polishing tape 7, and the upper surface of the polishing tape 7 (that is, the surface opposite to the polishing surface) is a pressing member. 11 is pressed. During the polishing of the wafer W, the pressing roller 52 is positioned on the outer side in the radial direction of the wafer W and the wafer stage 2 so that the pressing roller 52 does not contact the peripheral edge of the wafer W and the wafer stage 2.

As shown in FIG. 2, the

positioning rollers

23 and 24 are rotatably fixed to the load transmission member 27 of the polishing head 10. Although not shown, the two

positioning rollers

23 and 24 may be rotatably attached to the frame 39 of the polishing head 10. Even in this case, the pressing member 11 is positioned between the two

positioning rollers

23 and 24, and the

positioning rollers

23 and 24 are positioned at the contact point between the edge portion of the wafer W and the polishing tape 7. The 24 polishing tapes 7 are arranged so as to extend in the tangential direction of the wafer W.

As shown in FIGS. 1 and 2, the polishing apparatus further includes a rocking mechanism 5 that rocks the polishing head 10 in a predetermined direction D. The polishing head 10 having the

positioning rollers

23 and 24 can swing along the predetermined direction D by the swing mechanism 5.

In the present embodiment, the swing mechanism 5 includes a linear motion guide 40 extending in parallel with the predetermined direction D, a ball screw mechanism 41 coupled to the linear motion guide 40, and a servo motor 42 that drives the ball screw mechanism 41. And having. The linear motion guide 40 is fixed to the base 28, and the base 28 is supported by a frame (not shown) of the polishing apparatus. The servo motor 42 is supported on the base 28 via a support base 44. The ball screw mechanism 41 has a screw shaft 41a and a main body 41b that moves along the screw shaft 41a by the rotation of the screw shaft 41a. The main body 41 b of the ball screw mechanism 41 is connected to the frame 39 of the polishing head 10 via the connection block 43.

When the servo motor 42 is driven, the screw shaft 41 a of the ball screw mechanism 41 rotates, and the polishing head 10 connected to the main body 41 b of the ball screw mechanism 41 via the connecting block 43 moves along the linear motion guide 40. More specifically, when the servo motor 42 is driven in the forward rotation, the polishing head 10 moves forward along the linear motion guide 40, and when the servo motor 42 is driven in the reverse rotation, the polishing head 10 moves along the linear motion guide 40. To retreat. Since the linear motion guide 40 extends in parallel with the predetermined direction D, the polishing head 10 can be swung along the predetermined direction D by repeating forward and reverse rotations of the servo motor 42.

FIG. 4 is a schematic diagram showing the polishing tape 7 supported by the positioning roller 23. Since the positioning roller 24 has the same configuration as the positioning roller 23, the configuration of the positioning roller 23 will be mainly described below.

Since the positioning roller 23 is positioned outside the first guide roller 21 and the second guide roller 22 in the predetermined direction D (see FIG. 1), the first guide roller 21 and the second guide roller The track of the polishing tape 7 supported by 22 is shifted outward in the predetermined direction D by the

positioning rollers

23 and 24. A restoring force F is applied to the polishing tape 7 whose track has been shifted in the predetermined direction D so as to return to the track of the polishing tape 7 supported by the first guide roller 21 and the second guide roller 22. As a result, the inner edge 7 a of the polishing tape 7 supported by the positioning roller 23 is always pressed against the inner surface of the flange 34 of the positioning roller 23 by this restoring force F. Similarly, the inner edge 7 a of the polishing tape 7 supported by the positioning roller 24 is always pressed against the inner surface of the flange 35 of the positioning roller 24 by the restoring force F.

The edge portion of the wafer W is polished as follows. As shown in FIGS. 1 and 2, the wafer W is held on the wafer stage 2 so that a film (for example, a device layer) formed on the surface of the wafer W faces upward. At the same time, it is rotated around its axis. A polishing liquid (for example, pure water) is supplied to the center of the rotating wafer W from a liquid supply nozzle (not shown). The air cylinder 25 (see FIG. 3) of the polishing head 10 urges the pressing member 11 toward the wafer W, and the pressing member 11 presses the polishing tape 7 against the edge portion of the wafer W to polish the edge portion. During the polishing of the edge portion of the wafer W, the air cylinder 25 generates a certain force. During polishing of the edge portion of the wafer W, the polishing tape 7 is fed from the take-up reel 14 to the take-up reel 15 by the tape feeder 20 at a predetermined speed. Further, during polishing of the edge portion of the wafer W, the polishing head 10 is swung along the predetermined direction D by the swing mechanism 5. As the polishing head 10 swings, the polishing tape 7 supported by the

positioning rollers

23 and 24 of the polishing head 10 also swings along a predetermined direction D.

During the polishing of the edge portion of the wafer W, the

positioning rollers

23 and 24 in a state where the inner edge portion 7a of the polishing tape 7 is always pressed against the flanges 34 and 35 (see FIG. 4) of the

positioning rollers

23 and 24 by the restoring force F. The polishing tape 7 between them is rocked together with the polishing head 10 by the rocking mechanism 5. As a result, when the edge portion of the wafer W is polished with the polishing tape 7 while the polishing tape 7 is swung, the polishing tape 7 is prevented from being displaced with respect to the pressing member 11.

In the present embodiment, the polishing apparatus further prevents the polishing tape 7 from being displaced with respect to the pressing member 11 so that the upper surface of the polishing tape 7 (that is, the surface opposite to the polishing surface) is the pressing member 11. A pressing roller mechanism is provided that presses with a predetermined force. FIG. 5 is a diagram schematically showing a pressing roller mechanism according to an embodiment, and FIG. 6 is a perspective view of the pressing roller mechanism shown in FIG. In FIG. 6, the illustration of the polishing tape 7 is omitted, but the polishing tape 7 is sandwiched between the pressing roller 52 and the pressing member 11.

As shown in FIGS. 5 and 6, the pressing roller mechanism 50 includes three pressing roller units 51 arranged on the polishing surface side of the polishing tape 7. Each pressing roller unit 51 has a pressing roller 52 disposed on the polishing surface side of the polishing tape 7 and in contact with the polishing surface of the polishing tape 7. The pressure roller mechanism 50 includes three pressure roller units 51. However, the number of the pressure roller units 51 may be two or less, or may be four or more. That is, the pressing roller mechanism 50 includes at least one pressing roller unit 51. Each pressing roller unit 51 includes a bearing 55 that rotatably supports the pressing roller 52, a bearing block 56 that supports the bearing 55, and a support block 57 that supports the bearing block 56 (FIG. 9 to be described later). reference).

The pressing roller mechanism 50 further includes a biasing spring (biasing) that applies a biasing force to the pressing roller 52 of the pressing roller unit 51 to press the upper surface of the polishing tape 7 (that is, the surface opposite to the polishing surface) against the pressing member 11. Means) 54 and a biasing force adjusting mechanism 53 for adjusting the biasing force of the biasing spring 54.

As shown in FIG. 5, the three pressing roller units 51 are supported by the base block 58. The base block 58 is disposed below the pressing member holder 27 a of the load transmission member 27, and side through holes 58 a are formed on both sides of the base block 58. A screw shaft 71 is inserted in each side through hole 58a, and a gap is formed between the outer peripheral surface of the screw shaft 71 and the side through hole 58a. Accordingly, the base block 58 is movable along the screw shaft 71.

The screw shaft 71 extending through the side through hole 58 a is fixed to the pressing member holder 27 a of the load transmitting member 27. In the present embodiment, the pressing member holder 27 a is formed with two recesses 31 into which the screw shafts 71 are respectively inserted, and a lateral hole 32 communicating with each recess 31. The recess 31 extends in the vertical direction from the lower surface of the pressing member holder 27a, and the lateral hole 32 extends in the horizontal direction from the side surface of the pressing member holder 27a to the recess 31. The screw shaft 71 inserted into the recess 31 has an annular groove 71a formed in the upper part thereof. With the screw shaft 71 inserted in the recess 31 of the pressing member holder 27a, the fixing pin 36 is inserted into the lateral hole 32, and the tip of the fixing pin 36 is engaged with the annular groove 71a. Thereby, the screw shaft 71 is fixed to the pressing member holder 27 a of the load transmitting member 27.

Although not shown, the pressing member holder 27a of the load transmitting member 27 may have a screw hole into which each screw shaft 71 can be screwed. Each screw hole extends in the vertical direction from the lower surface of the pressing member holder 27a. By screwing the screw shaft 71 into the screw hole, the screw shaft 71 is fixed to the pressing member holder 27 a of the load transmitting member 27.

Furthermore, the pressing roller mechanism 50 has an adjustment nut 73 that can be screwed to each screw shaft 71, and the adjustment nut 73 is screwed into the screw shaft 71 from the lower end of the screw shaft 71. The biasing spring 54 is disposed between the base block 58 and the adjustment nut 73 and is supported by the adjustment nut 73. The biasing spring 54 is a coil spring extending in a spiral shape, and is arranged around a screw shaft 71 fixed to the pressing member holder 27a. That is, the screw shaft 71 extends in the biasing spring 54 that extends in a spiral shape. The base block 58 is urged toward the pressing member holder 27 a of the load transmission member 27 by the repulsive force of the urging spring 54.

As the adjusting nut 73 is screwed into the screw shaft 71, the pressing roller 52 of the pressing unit 51 moves toward the polishing tape 7 and contacts the polishing surface of the polishing tape 7. When the adjustment nut 73 is further screwed in, the urging spring 54 is gradually contracted, and the pressing roller 52 causes the upper surface of the polishing tape 7 (that is, the surface opposite to the polishing surface) by the repulsive force of the urging spring 54. Press against the pressing member 11. Therefore, the repulsive force of the contracted urging spring 54 corresponds to the urging force applied to the pressing roller 11 to press the polishing tape 7 against the pressing member 11. With this urging force, the pressing roller 52 can press the upper surface of the polishing tape 7 against the pressing member 11.

In this embodiment, the urging force adjusting mechanism 53 that adjusts the urging force of the urging spring 54 includes a screw shaft 71 and an adjusting nut 73. By adjusting the screwing amount of the adjustment nut 73 with respect to the screw shaft 71, the vertical length of the biasing spring 54 can be adjusted. More specifically, when the adjustment nut 73 screwed onto the screw shaft 71 is rotated and moved toward the base block 58, the biasing spring 54 is contracted. As a result, the urging force applied to the pressing roller 52 by the urging spring 54 increases. On the other hand, when the adjusting nut 73 screwed to the screw shaft 71 is moved in the direction away from the base block 58, the biasing spring 54 is extended. As a result, the urging force applied to the pressing roller 52 by the urging spring 54 is reduced. In this way, by adjusting the screwing amount of the adjusting nut 73 with respect to the screw shaft 71, the urging force by which the pressing roller 52 presses the polishing tape 7 against the pressing member 11 can be adjusted.

Although not shown, a biasing force for pressing the polishing tape 7 against the pressing member 11 may be applied to the pressing roller 52 of the pressing roller unit 51 using a piston cylinder mechanism. For example, the piston cylinder mechanism includes a cylinder that is fixed to a frame (not shown) of a polishing apparatus and extends in the vertical direction, and a piston that can move in the cylinder in the vertical direction. The upper end of the piston is fixed to the lower surface of the base block 58. Fluid is supplied to the cylinder, and the piston moves the base block 58 and the pressing roller 52 of the pressing roller unit 51 supported by the base block 58 in the vertical direction by the pressure of the fluid supplied to the cylinder. As a result, the pressing roller 52 pressed against the polishing surface of the polishing tape 7 presses the upper surface of the polishing tape 7 against the pressing roller 11. Furthermore, by adjusting the pressure of the fluid supplied to the cylinder, it is possible to adjust the urging force that the pressing roller 52 presses the polishing tape 7 against the pressing member 11.

According to the embodiment described above, the upper surface of the polishing tape 7 (that is, the surface opposite to the polishing surface) is pressed by the pressing roller 52 of the pressing roller unit 51 to which the biasing force of the biasing spring 54 is applied. Pressed against. As a result, during polishing of the edge portion of the wafer W, the polishing tape 7 that swings in the radial direction of the wafer W is appropriately held by the pressing member 11 and is prevented from being displaced with respect to the pressing member 11. That is, the polishing tape 7 can be sent along the intended track. Further, the urging force applied to the pressing roller 52 by the urging spring 54 can be adjusted by the urging force adjusting mechanism 53. Therefore, during polishing of the edge portion of the wafer W, the polishing tape 7 can be fed at an appropriate feed rate while preventing the orbit of the polishing tape 7 from deviating from the intended orbit.

Furthermore, the pressing roller mechanism 50 may include a separation mechanism for separating the pressing roller 52 of the pressing roller unit 51 from the polishing surface of the polishing tape 7 against the biasing force of the biasing spring 54. FIG. 7 is a cross-sectional view taken along the line AA in FIG. 5 and shows an example of a separation mechanism. FIG. 8 is a view showing a state where the pressing roller 52 is separated from the polishing surface of the polishing tape 7 by the separation mechanism shown in FIG. Hereinafter, an example of the separation mechanism will be described with reference to FIGS. 7 and 8.

As shown in FIG. 5, the separation mechanism 75 includes two piston cylinder units 76 disposed on both sides of the base block 58. Each cylinder unit 76 is disposed between the pressing roller unit 51 and the urging force adjusting mechanism 53 in the horizontal direction. As shown in FIG. 7, each piston cylinder unit 76 includes a cylinder 77 fixed to the base block 58, and a piston 78 that can move in the cylinder 77 by the pressure of the fluid supplied to the cylinder 77. .

Each cylinder 77 is connected to a fluid supply line (not shown) for supplying a fluid such as air or nitrogen. By supplying fluid to each cylinder 77, the piston 78 moves upward, and the tip of the piston 78 comes into contact with the lower surface of the pressing member holder 27 a of the load transmission member 27. The pressure of the fluid supplied to the cylinder 77 is set larger than the urging force of the urging member 64. Furthermore, since a gap is formed between the side through hole 58a of the base block 58 and the screw shaft 71 (see FIG. 5), the base block 58 is movable along the screw shaft 71. Therefore, the base block 58 is moved downward against the urging force of the urging spring 54 by the piston 78 in contact with the lower surface of the pressing member holder 27a. As a result, the pressing roller 52 of each pressing roller unit 51 supported by the base block 58 can be separated from the polishing surface of the polishing tape 7 by the separation mechanism 75 (see FIG. 8).

Thus, by separating the pressing roller 52 from the polishing tape 7, the polishing tape 7 can be easily replaced. When the polishing tape 7 is replaced, a fluid is supplied to each cylinder 77 of the separation mechanism 75 to separate the pressing roller 52 from the polishing tape 7. In this state, the polishing tape 7 is replaced. Since the polishing tape 7 is not pressed against the pressing member 11 by the pressing roller 52 during the replacement operation, the operator can easily replace the polishing tape 7. After the replacement of the polishing tape 7 is completed, the supply of fluid to the cylinder 77 is stopped, and the piston 78 is moved downward. As a result, the base block 58 moves toward the pressing member holder 27 a by the biasing force of the biasing spring 54, and the pressing roller 52 presses the polishing tape 7 against the pressing member 11.

The polishing tape 7 is wound as a wound body 8 on an unwinding reel 14 (see FIG. 1). When detecting the outer diameter of the wound body 8, the separation mechanism 75 may be operated to separate the pressing roller 52 from the polishing surface of the polishing tape 7. The detection of the outer diameter of the wound body 8 (hereinafter simply referred to as “outer diameter detection”) is performed, for example, when adjusting the torque applied to the take-up reel 14 and the take-up reel 15 by the

reel motors

17 and 18. Is called. The outer diameter of the wound body 8 may be detected in order to check the remaining amount of the polishing tape 7.

During polishing of the edge portion of the wafer W, the polishing tape 7 wound around the unwinding reel 14 is sent to the unwinding reel 15 via the polishing head 10. Therefore, the outer diameter of the wound body 8 gradually decreases. On the other hand, the take-up reel 15 winds up the polishing tape 7 as the wound body 9, so that the outer diameter of the wound body 9 gradually increases. If the rotational torque of the

reel motors

17 and 18 is kept constant and the polishing tape 7 is consumed and the outer diameter of the wound body 8 changes, the tension applied to the polishing tape 7 changes. The tension of the polishing tape 7 acts as a polishing load between the polishing tape 7 and the wafer W. Therefore, in order to keep the polishing load constant regardless of the consumption of the polishing tape 7, it is necessary to keep the tension of the polishing tape 7 constant regardless of the change in the outer diameter of the wound body 8 of the polishing tape 7. Therefore, it is necessary to control the output torque of the

reel motors

17 and 18 in accordance with the change in the outer diameter of the wound body 8 of the polishing tape 7 to control the rotational torque applied to the unwinding reel 14 and the take-up reel 15. Therefore, the polishing apparatus detects the outer diameter of the wound body 8 before starting the polishing of the edge portion of the wafer W, and adjusts the rotational torque applied to the unwinding reel 14 and the take-up reel 15.

In the present embodiment, the outer diameter detection of the wound body 8 is performed as follows. The polishing apparatus has a controller (not shown) that can control the operation of the entire polishing apparatus including the operations of the

reel motors

17 and 18. The control unit operates the

reel motors

17 and 18 and the tape feeding device 20 to feed the polishing tape 7 from the take-up reel 14 to the take-up reel 15 by a predetermined length L (for example, 20 mm). At this time, the control unit measures the number T of pulses output from the reel motor 17. After detecting the pulse number T, the control unit operates the

reel motors

17 and 18 to return the polishing tape 7 from the take-up reel 15 to the take-up reel 14 by a predetermined length L (for example, 20 mm). The control unit stores the following formula (1) in advance, and calculates the outer diameter r of the wound body 8 from the formula (1).
r = (2π · T) / (L · Ta) (1)
However, Ta is the number of pulses output to the control unit while the reel motor 17 rotates once. The control unit stores in advance the number Ta of pulses output during one rotation of the reel motor 17, and the number of pulses Ta, the predetermined length L, and the number of measured pulses are expressed in Equation (1). Substituting T, the outer diameter r of the wound body 8 is calculated.

As described above, in this embodiment, the polishing tape 7 is pressed against the pressing member 11 by the pressing roller 52 to which the biasing force of the biasing spring 54 is applied. In order to accurately detect the outer diameter of the wound body 8, it is preferable that only the tension due to the rotational torque of the take-up reel 14 and the take-up reel 15 is applied to the polishing tape 7. Therefore, when detecting the outer diameter of the wound body 8, the separation mechanism 75 is operated to separate the pressing roller 52 from the polishing tape 7.

Furthermore, the pressing roller unit 51 of the pressing roller mechanism 50 may have a tilt mechanism that can adjust the inclination angle of the pressing roller 52 with respect to the polishing surface of the polishing tape 7. FIG. 9 is a cross-sectional view taken along the line BB of FIG. 5 and shows an example of a tilt mechanism. For the convenience of explanation, in this specification, the direction indicated by the arrow G shown in FIG. 9 is defined as the forward direction, and the direction indicated by the arrow H is defined as the backward direction. The forward direction indicated by the arrow G and the backward direction indicated by the arrow H are perpendicular to the tangential direction of the wafer W at the contact point between the polishing tape 7 and the wafer W and are relative to the wafer holding surface 2 a of the wafer table 2. Parallel.

As shown in FIG. 9, the pressing roller unit 51 includes a pressing roller 52, a bearing 55 that rotatably supports the pressing roller 52, a bearing block 56 that supports the bearing 55, and a connecting block 61 that connects the bearing block 56. And a support block 57 to be supported. Accordingly, the pressing roller 52 is supported by the support block 57 via the bearing 55, the bearing block 56, and the connection block 61.

9 includes a connecting block 61 arranged between the bearing block 56 and the support block 57, an angle adjusting screw 62 for adjusting the angle of the bearing block 56 with respect to the polishing surface of the polishing tape 7, Two connection screws 64 and 65 for connecting the bearing block 56 to the support block 57 via the connection block 61 are provided. The connection block 61 is supported by a stepped portion 57 a formed in the support block 57.

The connecting block 61 has a main body 61a and a protrusion 61b protruding from the upper surface of the main body 61a. The upper surface 61c of the protrusion 61b has a cross-sectional shape that is substantially semicircular. On the lower surface of the bearing block 56, a recess 56a is formed in which the upper surface 61c of the protrusion 61b is in sliding contact. The concave portion 56a has a substantially semicircular cross-sectional shape, and the curvature of the cross section of the concave portion 56a is equal to the curvature of the cross section of the upper surface 61c of the protruding portion 61b. Therefore, the recess 56a and the upper surface 61c have the same fulcrum O. The bearing block 56 is supported on the upper surface 61 c of the protrusion 61 b by the recess 56 a of the bearing block 56. That is, the bearing block 56 is supported by the connection block 61 so as to be tiltable by the protrusion 61b of the connection block 61 (see arrow I in FIG. 9).

Near the rear end of the support block 57, a rear through hole 57b extending from the lower surface to the upper surface is formed, and the angle adjusting screw 62 is inserted into the rear through hole 57b. A gap is formed between the outer peripheral surface of the angle adjusting screw 62 and the rear through hole 57b. The main body 61a of the connection block 61 has a screw hole 61d into which the angle adjusting screw 62 is screwed. The screw hole 61d extends from the lower surface to the upper surface of the main body 61a of the connection block 61. The angle adjusting screw 62 is screwed into the screw hole 61 d through the rear through hole 57 b of the support block 57. The angle adjusting screw 62 screwed into the screw hole 61 d extends in the vertical direction through the connecting block 61. A flange portion 56b is formed at the rear end of the bearing block 56, and the tip end of the angle adjusting screw 62 is in contact with the flange portion 56b.

The inclination angle of the bearing block 56 with respect to the connection block 61 can be adjusted by adjusting the screwing amount of the angle adjusting screw 62 with respect to the screw hole 61d of the connection block 61. For example, the angle adjustment screw 62 is rotated clockwise and moved upward with respect to the screw hole 61 d, whereby the tip of the angle adjustment screw 62 pushes up the flange portion 56 b of the bearing block 56. As a result, the bearing block 56 rotates about the fulcrum O so that the rear end of the bearing block 56 rises and the front end of the bearing block 56 falls. By rotating the angle adjusting screw 62 counterclockwise and moving it downward relative to the screw hole 61d, the front end of the bearing block 56 is raised and the rear end of the bearing block 56 is lowered. Thus, it rotates around the fulcrum O. Since the pressing roller 52 is supported by the bearing block 56 via the bearing 55, the inclination angle of the pressing roller 52 with respect to the polishing surface of the polishing tape 7 (that is, the angle of the pressing roller 52 that contacts the polishing surface of the polishing tape 7). ) Can be adjusted.

After adjusting the inclination angle of the pressing roller 52, the bearing block 56 is fixed to the support block 57 via the connection block 61 by the front connection screw 64 and the rear connection screw 65. The support block 57 has a front through hole 57c into which the front connection screw 64 is inserted, and an intermediate through hole 57d into which the rear connection screw 65 is inserted. The front through hole 57c is formed in a region where the stepped portion 57a that supports the connecting block 61 is not formed. The intermediate through hole 57d is located between the front through hole 57d and the rear through hole 57c, and is formed in the region of the step portion 57a that supports the connecting block 61. A gap is formed between the outer peripheral surface of the front connection screw 64 and the front through hole 57c. Similarly, a gap is formed between the outer peripheral surface of the rear connection screw 65 and the intermediate through hole 57d.

In the main body 61a of the connecting block 61, a through hole 61e into which the rear connecting screw 65 inserted into the intermediate through hole 57d can be inserted is formed. The through hole 61 e of the connection block 61 extends from the upper surface to the lower surface of the connection block 61, and a gap is formed between the outer peripheral surface of the rear connection screw 65 and the through hole 61 e of the connection block 61.

The tip of the front connection screw 64 that has passed through the front through hole 57 c of the support block 57 is screwed into a front screw hole 56 c formed on the lower surface of the bearing block 56. A spring washer 68 is disposed between the head of the front connection screw 64 and the lower surface of the support block 57. The tip of the rear connection screw 65 that has passed through the intermediate through hole 57 d of the support block 57 and the through hole 61 e of the connection block 61 is screwed into a rear screw hole 56 d formed on the lower surface of the bearing block 56. A spring washer 69 is disposed between the head of the rear connection screw 65 and the lower surface of the support block 57.

FIG. 10 is a view showing a state in which the bearing block 56 and the pressing roller 52 supported by the bearing block 56 via the bearing 55 are inclined with respect to the horizontal plane. The inclination angle of the bearing block 56 is, for example, in the range of about + 1 ° to −1 ° with respect to the horizontal plane.

As shown in FIG. 10, the bearing block 56 and the pressing roller 52 can be inclined with respect to the horizontal plane by adjusting the screwing amount of the angle adjusting screw 62 with respect to the screw hole 61d. The front connection screw 64 that is screwed into the front screw hole 56 c formed on the lower surface of the bearing block 56 is also inclined, but the amount of inclination of the front connection screw 64 with respect to the horizontal plane is absorbed by the spring washer 68. Similarly, the rear connection screw 65 screwed into the rear screw hole 56d formed on the lower surface of the bearing block 56 is also inclined, but the amount of inclination of the rear connection screw 65 with respect to the horizontal plane is absorbed by the spring washer 69.

In this manner, the inclination angle at which the pressing roller 52 presses the polishing tape 7 against the pressing member 11 is adjusted by inclining the bearing block 56 and the pressing roller 52 with respect to the horizontal plane (that is, with respect to the polishing tape 7). Can do.

9 is provided in each pressing roller unit 51. The tilt mechanism 60 shown in FIG. Therefore, when a plurality of pressing roller units 51 are provided, the inclination angle of the pressing roller 52 of each pressing roller unit 51 can be individually adjusted.

FIG. 11 is a view showing an example of a height adjusting member for adjusting the height of the pressing roller unit in the vertical direction. As shown in FIG. 11, the pressing roller unit 51 may include a shim 67 disposed between the connection block 61 and the support block 57. In this case, the bearing block 56 is supported by the support block 57 via the connection block 61 and the shim 67. This shim 67 is used as a height adjusting member. In the present embodiment, the shim 67 has a through hole into which the rear connection screw 65 is inserted and a through hole into which the angle adjusting screw 62 is inserted.

The height of the pressing roller 52 in the vertical direction can be adjusted by a shim 67 disposed between the connection block 61 and the support block 57. When a plurality of pressing roller units 51 are provided, the shim 67 can be disposed in each pressing roller unit 51. The width of the shim 67 in the vertical direction is arbitrary. Therefore, the vertical height of each pressing roller 52 can be individually adjusted.

Furthermore, the polishing apparatus may include a position adjustment mechanism that can adjust the position of the pressing roller 11 in the radial direction of the wafer W. FIG. 12 is a cross-sectional view taken along the line CC of FIG. 5 and is a diagram illustrating an example of a position adjusting mechanism.

12 includes a horizontal hole 81 extending from the side surface of the support block 57 to the vertical surface of the stepped portion 57b, and a position adjusting screw 82 inserted into the horizontal hole 81. In the present embodiment, the position adjusting mechanism 80 is configured by the two sets of lateral holes 81 and the position adjusting screw 82 (see FIGS. 5 and 6). Each lateral hole 81 is formed with a thread groove, and the position adjusting screw 82 can be screwed into the thread groove. The tip of the position adjusting screw 82 protrudes from the rear end of the horizontal hole 81 and contacts the front surface of the connecting block 61. By adjusting the screwing amount of the position adjusting screw 82 with respect to the horizontal hole 81, the horizontal position of the pressing roller 52 with respect to the polishing tape 7 can be adjusted.

As shown in FIG. 9, a gap is formed between the front connecting screw 64 and the front through hole 57 c of the support block 57. A gap is formed between the rear connection screw 65 and the intermediate through hole 57 d of the support block 57, and a gap is also formed between the rear connection screw 65 and the through hole 61 e of the connection block 61. . Further, a gap is also formed between the angle adjusting screw 62 screwed into the screw hole 61 d of the connection block 61 and the rear through hole 57 b of the support block 57. Therefore, when the position adjusting screw 82 is moved rearward (that is, in the direction of the arrow H shown in FIG. 9), the connecting block 61 becomes the bearing block 56, the bearing 55, the pressing roller 52, the front connecting screw 64, and the rear. It moves backward together with the connecting screw 65 and the angle adjusting screw 62 (see FIG. 13). When the position adjusting screw 82 is moved forward (that is, in the direction of arrow G shown in FIG. 9), the connecting block 61 is moved to the bearing block 56, the bearing 55, the pressing roller 52, the front connecting screw 64, the rear connecting screw 65, And it can be moved forward together with the angle adjusting screw 62. In this way, by adjusting the screwing amount of the position adjusting screw 82 with respect to the lateral hole 81, the horizontal position of the pressing roller 52 with respect to the polishing tape 7 can be adjusted.

FIG. 14 is a diagram schematically showing a pressing roller mechanism according to another embodiment. The pressing roller mechanism 50 ′ shown in FIG. 14 includes two pressing roller units 51 arranged on the polishing surface side of the polishing tape 7. The configuration of each pressing roller unit 51 shown in FIG. Since it is the same as that of the structure of the press roller unit 51 which concerns on embodiment, the detailed description is abbreviate | omitted.

Further, the pressing roller mechanism 50 ′ applies a biasing force that presses the base block 58 ′ supporting the pressing roller unit 51 and the upper surface of the polishing tape 7 (that is, the surface opposite to the polishing surface) against the pressing member 11. And an urging force adjusting mechanism 53 ′ for adjusting the urging force of the urging spring 54 ′. In the present embodiment, the base block 58 ′ is fixed to the pressing member holder 27 a of the load transmission member 27. More specifically, the upper end of the base block 58 'is fixed to the lower surface of the pressing member holder 27a by a fixing tool (not shown) such as a screw.

14 includes a nut 85 fixed to the base block 58 'and a cap 86 having an inner surface that can be screwed into a thread groove formed on the outer surface of the nut 85. The urging force adjusting mechanism 53' shown in FIG. The nut 85 is fixed to the bottom wall of the base block 58 '. A biasing spring 54 ′ that applies a biasing force to the pressing roller 52 ′ that presses the upper surface of the polishing tape 7 (that is, the surface opposite to the polishing surface) against the pressing member 52 ′ is a coil spring that extends in a spiral shape. The biasing spring 54 ′ is disposed between the support block 57 of the pressing roller unit 51 and the nut 85, and is supported by the nut 85. Due to the repulsive force of the urging spring 54 ′, the pressing roller unit 51 is urged toward the pressing member holder 27 a of the load transmitting member 27. In the present embodiment, a flat seat 93 is disposed between the lower end of the biasing spring 54 ′ and the nut 85, and the biasing spring 54 ′ is supported by the nut 85 via the flat seat 93. The

In the present embodiment, the biasing force applied to the pressing member 11 by the biasing spring 54 ′ can be adjusted by adjusting the screwing amount of the cap 86 with respect to the nut 85. More specifically, when the cap 86 is moved toward the pressing roller unit 51, the biasing spring 54 'contracts. As a result, the urging force applied to the pressing roller 52 of the pressing roller unit 51 by the urging spring 54 'increases. On the other hand, when the cap 86 is moved away from the pressing roller unit 51, the biasing spring 54 'extends. As a result, the biasing force applied to the pressing roller 52 of the pressing roller unit 51 by the biasing spring 54 'is reduced. In this way, by adjusting the screwing amount of the cap 86 with respect to the nut 85, it is possible to adjust the urging force by which the pressing roller 52 presses the polishing tape 7 against the pressing holder 27a of the load transmitting member 27.

The pressing roller mechanism 50 ′ may include a separation mechanism 75 ′ for separating the pressing roller 52 from the polishing surface of the polishing tape 7 against the urging force of the urging spring 54 ′. In the present embodiment, the separation mechanism 75 ′ includes a bar-shaped member 88 fixed to the support block 57 of each pressing roller unit 51, a plate member 92 disposed below the base block 58 ′, and each bar-shaped member 88. And a stopper 89 for fixing to the member 92. The biasing spring 54 ′ is disposed around the rod-shaped member 88. That is, the rod-shaped member 88 extends in the biasing spring 54 ′ that extends in a spiral shape.

One end (upper end) of the rod-shaped member 88 is fixed to the support block 57 of the pressing roller unit 51, and the rod-shaped member 88 extends from the lower surface of the support block 57 in the vertical direction. The cap 86 and the nut 85 are formed with through holes into which the rod-shaped member 88 is inserted, respectively, between the outer surface of the rod-shaped member 88 and the through-hole of the cap 86, and between the outer surface of the rod-shaped member 88 and the nut 85. A gap is formed between the holes. Similarly, a through hole into which the rod-shaped member 88 is inserted is formed in the base block 58 ', and a gap is formed between the outer surface of the rod-shaped member 88 and the through hole of the base block 58'. The lower end portion of the rod-shaped member 88 is fixed to the lower surface of the plate member 92 by a stopper 89. Therefore, the rod-shaped member 88 and the plate member 92 are movable in the vertical direction with respect to the cap 86, the nut 85, and the base block 58 '.

Furthermore, the separation mechanism 75 ′ has two piston cylinder units 76 ′ disposed on both sides of the plate member 92. Each cylinder unit 76 ′ includes a cylinder 77 ′ fixed to the plate member 92 and a piston 78 ′ movable within the cylinder 77 ′ by the pressure of fluid supplied to the cylinder 77 ′. The cylinder 77 ′ is opened upward so that the tip of the piston 78 ′ can come into contact with the lower surface of the base block 58 ′ fixed to the pressing member holder 27 a of the load transmission member 27.

Each cylinder 77 'is connected to a fluid supply line (not shown) for supplying a fluid such as air or nitrogen. By supplying fluid to each cylinder 77 ', the piston 78' moves upward, and the tip of the piston 78 'contacts the lower surface of the base block 58'. The pressure of the fluid supplied to each cylinder 77 'is set larger than the urging force of the urging member 54'. Therefore, the plate member 92, the rod-shaped member 88 fixed to the plate member 92, and the pressing roller unit 51 fixed to the rod-shaped member 88 by the piston 78 ′ that presses the lower surface of the base block 58 ′ with the pressure of the fluid. It is moved downward against the biasing force of the biasing spring 54 '. As a result, the pressing roller 52 can be separated from the polishing surface of the polishing tape 7 (see FIG. 15).

Thus, by separating the pressing roller 52 from the polishing tape 7, the polishing tape 7 can be easily replaced. Furthermore, the outer diameter of the wound body 8 (see FIG. 1) of the polishing tape 7 can be accurately detected.

In the embodiment shown in FIGS. 14 and 15, the pressing roller mechanism 50 ′ includes two pressing roller units 51, but the number of pressing roller units 51 may be one, or three or more. There may be. That is, the pressing roller mechanism 50 ′ includes at least one pressing roller unit 51.

FIG. 16 is a plan view schematically showing a polishing apparatus according to another embodiment, and FIG. 17 is a side view of the polishing apparatus shown in FIG. The configuration of the present embodiment that is not specifically described is the same as that of the polishing apparatus shown in FIGS. 1 and 2, and thus redundant description thereof is omitted.

16 and 17, the polishing tape 7 extends from the unwinding reel 14 to the take-up reel 15 in parallel to the tangential direction of the wafer W. In the polishing apparatus shown in FIGS. That is, the

positioning rollers

23 and 24 are linearly arranged with the

guide rollers

21 and 22 in a direction parallel to the tangential direction of the wafer W (see FIG. 16). Also in this embodiment, the

positioning rollers

23 and 24 are arranged such that the polishing tape 7 between the

positioning rollers

23 and 24 extends in the tangential direction of the wafer W at the contact point between the edge portion of the wafer W and the polishing tape 7. Yes.

16 and 17 can be provided with the pressing roller mechanism 50 (or 50 ') according to the above-described embodiment. The pressing roller mechanism 50 (or 50 ′) prevents the polishing tape 7 from being displaced from the pressing member 11 during polishing of the edge portion of the wafer W. That is, the pressing roller mechanism 50 (or 50 ') can prevent the track of the polishing tape 7 from deviating from the intended track.

Although not shown, the rocking mechanism 5 may be omitted in the polishing apparatus shown in FIGS. Further, the swinging mechanism 5 shown in FIGS. 1 and 2 is arranged in the polishing apparatus shown in FIGS. 16 and 17, and the polishing tape 7 and the polishing head 10 are swung in a predetermined direction D perpendicular to the tangent to the wafer W. It may be moved.

The above-described embodiments are described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in the widest scope according to the technical idea defined by the claims.

The present invention can be used in a polishing apparatus that presses a polishing tape against an edge portion of a substrate to polish the edge portion.

1 Wafer holder (substrate holder)
2 Wafer stage 2a Wafer holding surface (substrate holding surface)
DESCRIPTION OF SYMBOLS 5 Oscillation mechanism 7 Polishing tape 10 Polishing head 11 Pressing member 14 Unwinding reel 15 Take-up reel 23 Positioning roller 24 Positioning roller 27 Load transmission member 27a Pressing member holder 50 Pressing roller mechanism 51 Pressing roller unit 51 Pressing roller 53 Adjusting urging force Mechanism 54 Biasing spring (Biasing means)
55 Bearing 56 Bearing block 57 Support block 58 Base block 60 Tilt mechanism 61 Connection block 62 Angle adjustment screw 64 Front connection screw 65 Rear connection screw 71 Screw shaft 71a Annular groove 73 Adjustment nut 75 Separation mechanism 76 Piston cylinder unit 77 Cylinder 78 Piston 80 Position adjusting mechanism 81 Horizontal hole 82 Position adjusting screw 85 Nut 86 Cap 88 Bar-shaped member 89 Stopper 92 Plate member

Claims

A substrate holder for holding and rotating the substrate;
A pressing member that presses the polishing surface of the polishing tape against the edge portion of the substrate;
A load transmitting member for transmitting a load pressing the polishing surface of the polishing tape against the edge portion to the pressing member;
A pressing roller mechanism disposed on the polishing surface side of the polishing tape,
The pressing roller mechanism is
At least one pressing roller unit having a pressing roller in contact with the polishing surface of the polishing tape;
An urging means for applying an urging force to the pressing roller to press the surface opposite to the polishing surface of the polishing tape against the pressing member;
A polishing apparatus comprising: an urging force adjusting mechanism that adjusts an urging force of the urging means.
The polishing apparatus according to claim 1, wherein the pressing roller unit has a tilt mechanism capable of adjusting an inclination angle of the pressing roller with respect to a polishing surface of the polishing tape.
The pressing roller unit is
A bearing that rotatably supports the pressing roller;
A bearing block for supporting the bearing;
A support block that supports the bearing block via a connection block;
The tilt mechanism is
A screw hole penetrating the connecting block;
An angle adjusting screw that is screwed into a screw hole formed in the connection block and contacts the bearing block;
The bearing block is supported so as to be tiltable on an upper surface of a protrusion formed on the connection block,
The polishing apparatus according to claim 2, wherein an inclination angle of the pressing roller is changed together with the bearing block by adjusting a screwing amount of the angle adjusting screw with respect to the screw hole.
The pressing roller unit is
A bearing that rotatably supports the pressing roller;
A bearing block for supporting the bearing;
A support block for supporting the bearing block via a connecting block;
The polishing apparatus according to claim 1, further comprising a position adjustment mechanism capable of adjusting a position of the pressing roller in a radial direction of the substrate.
The connection block is disposed on a step formed on the support block;
The position adjustment mechanism is
A lateral hole extending from a side surface of the support block to a vertical surface of the step,
A position adjusting screw screwed into the lateral hole,
The polishing apparatus according to claim 4, wherein the position of the pressing roller is changed together with the connection block by adjusting a screwing amount of the position adjusting screw with respect to the lateral hole.
The pressing roller unit is
A bearing that rotatably supports the pressing roller;
A bearing block for supporting the bearing;
A support block that supports the bearing block via a connection block;
The polishing apparatus according to claim 1, wherein the pressing roller unit further includes a height adjusting member disposed between the connection block and the support block.
The pressure roller mechanism further includes a base block that supports the pressure roller unit and is disposed below the load transmission member,
The biasing force adjusting mechanism is
A screw shaft extending through the base block and fixed to the load transmission member;
An adjustment nut screwed onto the screw shaft,
The polishing apparatus according to claim 1, wherein the biasing means is a biasing spring disposed between the base block and the adjustment nut.
The pressure roller mechanism further includes a separation mechanism for separating the pressure roller from the polishing surface of the polishing tape,
The separation mechanism is a piston cylinder unit fixed to both sides of the base block,
Each piston cylinder unit
A cylinder fixed to the base block;
A piston movable within the cylinder by a fluid supplied to the cylinder, and
The fluid pressure is greater than the urging force applied to the pressing roller by the urging member,
The polishing apparatus according to claim 7, wherein the fluid is supplied to the cylinder so that a tip of the piston comes into contact with the load transmission member and moves the pressing roller together with the base block. .
The pressing roller mechanism is
A base block that supports the pressure roller unit and is fixed to the load transmission member;
The biasing force adjusting mechanism is
A nut fixed to the base block;
A cap having an inner surface that can be screwed into a thread groove formed on the outer surface of the nut,
The polishing apparatus according to any one of claims 1 to 6, wherein the biasing means is a biasing spring disposed between the nut and the cap.
The pressure roller mechanism further includes a separation mechanism for separating the pressure roller from the polishing surface of the polishing tape,
The separation mechanism is
A rod-like member fixed to the pressing roller unit and extending downward;
A plate member disposed below the base block;
A stopper for fixing the lower end of the rod-shaped member to the plate member;
A piston cylinder unit disposed on both sides of the plate member, and
The piston cylinder unit is
A cylinder fixed to the plate member;
A piston movable within the cylinder by a fluid supplied to the cylinder, and
The fluid pressure is greater than the urging force applied to the pressing roller by the urging member,
The polishing apparatus according to claim 9, wherein by supplying the fluid to the cylinder, the tip of the piston comes into contact with the base block and moves the pressing roller together with the plate member.