TW202110577A - Polishing device - Google Patents

Abstract

The present invention relates to a polishing device for forming a recess in a peripheral section of a bonded wafer or other substrate, with the recess having an orthogonal cross-sectional shape. The polishing device comprises a polishing head (8) having a pressing member (5) for pressing a polishing tape (T) onto a peripheral section of a substrate (W) which is on a substrate holding plane (1a). The pressing member (5) includes: a pressing surface (5A) that is parallel to the substrate holding plane (1a); and an inclined surface (5B) that is connected to the inner edge of the pressing surface (5A), with the angle formed by the pressing surface (5A) and the inclined surface (5B) being an acute angle. The polishing head (8) comprises a positioning roller (33) that determines the relative position of the polishing tape (T) in relation to the inclined surface (5B). An angle of the polishing tape (T) that extends between the positioning roller (33) and the pressing member (5) is an acute angle relative to the pressing surface (5A).

Description

Grinding device

The present invention relates to a polishing apparatus for forming pits with a right-angle cross-sectional shape on the peripheral edge of a substrate such as a bonded wafer.

In order to polish the peripheral edge of a wafer as an example of a substrate, a polishing apparatus equipped with a grindstone 500 as shown in FIG. 15 is used. This type of polishing device grinds the peripheral edge of the wafer W by rotating the wafer W and the grindstone 500, and the grindstone 500 is brought into contact with the peripheral edge of the wafer W to form a cross section with a right angle as shown in FIG. 16 Shaped pit 505.

The polishing apparatus shown in FIG. 15 is used especially in the step of bonding wafers to thin them. As shown in FIG. 17A, the wafer W is made by bonding a patterned pattern wafer W1 with a patterned wafer W1 and a support wafer W2 composed of a silicon wafer, etc., with an oxide film or adhesive (indicated by the symbol 200). . As shown in FIG. 17B, by rotating the wafer W and pressing the grindstone 500 against the peripheral edge of the wafer W, as shown in FIG. 17C, a pit 510 with a right-angle cross-sectional shape is formed on the peripheral edge of the wafer W. .

However, in the polishing wafer W, since the polishing surface of the grindstone 500 cannot be renewed (dressed), when the grindstone 500 is clogged, the polishing rate is likely to decrease. In addition, because the amount of material to be removed from the wafer W is large, there is a problem that the life of the grindstone 500 is very short.

Therefore, instead of the grinding stone 500, a grinding device using the grinding belt 600 as shown in FIG. 18A is proposed. The polishing tape 600 moves in its longitudinal direction, and the polishing surface of the polishing tape 600 is pressed against the peripheral edge of the wafer W by the pressing member 601. In polishing the wafer W, since the polishing belt 600 moves in its length direction, it is not easy to cause clogging of the polishing surface of the polishing belt 600, and a stable polishing rate is achieved. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2011-177842 A [Patent Document 2] JP 2011-224680 A

(The problem to be solved by the invention)

However, it can be understood from FIG. 18A that the polishing tape 600 extends from the pressing member 601 to the outside, and the part of the polishing tape 600 extending to the outside contacts the peripheral edge of the wafer W obliquely. As a result, as shown in FIG. 18B, the inclined surface 610 is formed on the peripheral edge portion of the wafer W, and a pit having a right-angle cross-sectional shape cannot be formed.

Therefore, the present invention provides a polishing device that can form pits having a right-angled cross-sectional shape on a substrate such as a wafer by using a polishing tape. (Means to solve the problem)

One aspect provides a polishing device, which is provided with: a holding stage having a substrate holding surface for holding a substrate; and a polishing head having a peripheral portion of the substrate for pressing a polishing tape on the substrate holding surface A pressing member; and an actuator, which moves the polishing head in a direction perpendicular to the substrate holding surface; the pressing member has: a pressing surface parallel to the substrate holding surface; and an inclined surface, which It is connected to the inner edge of the pressing surface; the angle formed by the pressing surface and the inclined surface is an acute angle. The grinding head is equipped with a positioning roller, which defines the relative position of the grinding belt to the inclined surface. The angle of the abrasive belt extending between the positioning roller and the pressing member to the pressing surface is an acute angle.

One aspect is that the relative position of the positioning roller and the pressing member is fixed. One aspect is that the angle of the grinding belt extending between the positioning roller and the pressing member to the pressing surface is in the range of 30 to 90 degrees. One aspect is that the aforementioned polishing head further has: a sequential unwinding shaft, which discharges the aforementioned abrasive tape in sequence; a reeling shaft, which retracts the aforementioned abrasive tape; and a base, which holds the aforementioned positioning roller and the aforementioned pressing The components, the aforementioned unwinding reel in sequence, and the aforementioned reeling reel. One aspect is that the aforementioned grinding device is further equipped with: a sequential unwinding shaft, which sequentially releases the aforementioned grinding tape; and a rewinding shaft, which rewinds the aforementioned grinding tape; the aforementioned sequential unwinding shaft and the aforementioned winding reel are arranged at The same height as the aforementioned polishing head. One aspect is that the substrate holding surface is the same size as the substrate or larger than the substrate.

One aspect provides a polishing device, which is provided with: a holding stage having a substrate holding surface for holding a substrate; and a polishing head having a peripheral portion of the substrate for pressing a polishing tape on the substrate holding surface A pressing member; and an actuator that moves the polishing head in a direction parallel to the substrate holding surface; the pressing member has: a pressing surface perpendicular to the substrate holding surface; and an inclined surface, which It is connected to the lower edge of the pressing surface; the angle formed by the pressing surface and the inclined surface is an acute angle. The grinding head is equipped with a positioning roller, which defines the relative position of the grinding belt to the inclined surface. The angle of the abrasive belt extending between the positioning roller and the pressing member to the pressing surface is an acute angle.

One aspect is that the relative position of the positioning roller and the pressing member is fixed. One aspect is that the angle of the grinding belt extending between the positioning roller and the pressing member to the pressing surface is in the range of 30 to 90 degrees. One aspect is that the aforementioned polishing head further has: a sequential unwinding shaft, which discharges the aforementioned abrasive tape in sequence; a reeling shaft, which retracts the aforementioned abrasive tape; and a base, which holds the aforementioned positioning roller and the aforementioned pressing The components, the aforementioned unwinding reel in sequence, and the aforementioned reeling reel. One aspect is that the aforementioned grinding device is further equipped with: a sequential unwinding shaft, which sequentially releases the aforementioned grinding tape; and a rewinding shaft, which rewinds the aforementioned grinding tape; the aforementioned sequential unwinding shaft and the aforementioned winding reel are arranged at Above the aforementioned grinding head. One aspect is that the substrate holding surface is the same size as the substrate or larger than the substrate. (Effects of Invention)

When the present invention is adopted, since the inclined surface is at an acute angle to the pressing surface, the abrasive belt extends obliquely along the inclined surface. Since the portion of the polishing tape extending along the inclined surface does not touch the peripheral edge of the substrate, the polishing tape pressed against the peripheral edge of the substrate by the pressing surface can form pits with a right-angle cross-sectional shape on substrates such as wafers. on.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. This specification defines the peripheral edge portion of the substrate as an area, which includes: a bevel portion located on the outermost periphery of the substrate; and a top edge portion and a bottom edge portion located on the radially inner side of the bevel portion. The substrate is, for example, a wafer.

1A and 1B are enlarged cross-sectional views showing the peripheral edge of the substrate. In more detail, FIG. 1A is a cross-sectional view of a so-called straight substrate, and FIG. 1B is a cross-sectional view of a so-called round substrate. In the substrate W of FIG. 1A, the groove portion is the uppermost portion of the substrate W composed of an upper inclined portion (upper groove portion) P, a lower inclined portion (lower groove portion) Q, and a side portion (apex) R. Peripheral surface (represented by symbol B). In the substrate W of FIG. 1B, the groove portion is a portion (indicated by symbol B) that constitutes the outermost peripheral surface of the substrate W and has a curved cross-section. The top edge portion is a flat annular portion E1 located on the inner side of the groove portion B in the radial direction. The bottom edge portion is located on the opposite side to the top edge portion E1, and is a flat annular portion E2 located on the inner side of the groove portion B in the radial direction. The top edge portion E1 also includes a region where elements are formed. The top edge portion E1 and the bottom edge portion E2 are connected to the groove portion B.

Fig. 2 is a schematic diagram showing an embodiment of the polishing device. The polishing apparatus of the present embodiment is used for polishing the peripheral edge portion of the wafer W, which is an example of a substrate, and forming pits having a right-angle cross-sectional shape in the peripheral edge portion. A specific example of the wafer W is the bonded wafer shown in FIG. 17A.

As shown in FIG. 2, the polishing apparatus of this embodiment includes: a holding stage 1 having a substrate holding surface 1a for holding a wafer W as an example of a substrate; and the holding stage 1 is centered on the axis CL of the substrate holding surface 1a A stage rotating device 3 that rotates as the center; a polishing head 8 having a pressing member 5 for pressing the polishing tape T on the peripheral edge of the wafer W on the substrate holding surface 1a; and the polishing head 8 is placed on the substrate The actuator 12 moves in the vertical direction of the holding surface 1a.

An opening 1 b such as a hole or a groove is formed on the substrate holding surface 1 a, and the opening 1 b is connected to the vacuum line 15. It is also possible to provide a plurality of openings 1b. In a state where the lower surface of the wafer W is placed on the substrate holding surface 1a, when a vacuum is formed in the opening 1b, the wafer W is held on the substrate holding surface 1a by the vacuum. The substrate holding surface 1a has the same shape as the wafer W. The wafer W in this embodiment is circular, and the substrate holding surface 1a is also circular. The substrate holding surface 1a has the same size as the wafer W. That is, the diameter of the substrate holding surface 1a is the same as the diameter of the wafer W. Therefore, the entire lower surface of the wafer W is held by the substrate holding surface 1a. In one embodiment, the substrate holding surface 1a may be larger than the wafer W.

The stage rotating device 3 includes a motor and the like. The stage rotating device 3 is connected to a stage shaft 1c fixed to the lower part of the holding stage 1. When the stage rotating device 3 operates, the holding stage 1 and the stage shaft 1c integrally rotate around the axis CL of the substrate holding surface 1a. The wafer W is held on the substrate holding surface 1a such that the axis of the wafer W coincides with the axis CL of the substrate holding surface 1a. Therefore, the wafer W and the holding stage 1 integrally rotate around the axis of the wafer W (that is, the axis CL of the substrate holding surface 1 a).

A liquid supply nozzle 18 is arranged above the substrate holding surface 1a. The liquid supply nozzle 18 is connected to a liquid supply line (not shown) to supply liquid such as pure water or alkaline water to the center of the wafer W. The liquid supplied to the center of the rotating wafer W is spread over the entire upper surface of the wafer W by centrifugal force, which can protect the upper surface of the wafer W from damage by particles such as grinding debris.

The polishing head 8 is arranged above the outer periphery of the substrate holding surface 1a. The polishing head 8 is connected to the actuator 12. The actuator 12 is held by a holding member such as a bracket (not shown). The specific structure of the actuator 12 is not particularly limited. For example, the actuator 12 can be composed of an air cylinder, or a combination of a ball screw mechanism and a servo motor.

The polishing head 8 is provided with: a sequential unwinding shaft 21 for sequentially unwinding the abrasive tape T; a reeling shaft 22 for winding the abrasive tape T; and a tape feeding mechanism 25 for sending out the abrasive tape T in its length direction. The unwinding shaft 21, the winding reel 22, the pressing member 5, and the tape feeding mechanism 25 are moved integrally by the actuator 12 in order.

The pressing member 5 is arranged above the outer periphery of the substrate holding surface 1a. The pressing member 5 is located directly above the peripheral edge of the wafer W held on the substrate holding surface 1a. The pressing member 5 supports the back side of the polishing tape T, and polishes the peripheral edge of the wafer W by pressing the polishing surface (front side) of the polishing tape T against the peripheral edge of the wafer W. The polishing surface of the polishing belt T has abrasive grains fixed on it. The aforementioned actuator 12 moves the pressing member 5 toward the peripheral edge of the wafer W, whereby the pressing member 5 can press the polishing tape T against the peripheral edge of the wafer W. The force of the pressing member 5 to press the polishing tape T on the periphery of the wafer W (ie, the polishing load) can be adjusted by the actuator 12. The polishing tape T at the polishing point of the wafer W extends in the radial direction of the wafer W (that is, the radial direction of the substrate holding surface 1a).

The polishing head 8 has a sensor mark 28. The sensor mark 28 can be moved integrally with the pressing member 5 by the actuator 12. The polishing device includes a displacement sensor 30 arranged toward the sensor target 28. The displacement sensor 30 is configured to measure the moving distance of the sensor target 28, that is, the moving distance of the polishing head 8. The displacement sensor 30 is, for example, a contact displacement sensor or a non-contact displacement sensor. Such contact type displacement sensors and non-contact type displacement sensors are available on the market. In one embodiment, the sensor mark 28 may not be specially provided, and the displacement sensor 30 may be used to measure the moving distance of the polishing head 8.

The displacement sensor 30 is connected to the motion control unit 34, and the measured value of the movement distance of the polishing head 8 is transmitted from the displacement sensor 30 to the motion control unit 34. The operation control unit 34 is configured to determine the polishing end point of the wafer W based on the measured value of the moving distance of the polishing head 8. The operation control unit 34 is composed of at least one computer. The action control unit 34 includes: a memory device 34a that stores a program for determining the polishing end point of the wafer W based on the measured value of the movement distance of the polishing head 8; and a processing device 34b (CPU or GPU, etc.).

The wafer W is polished as follows. The wafer W is set on the substrate holding surface 1a by a conveying device (not shown) so that its center coincides with the axis CL of the substrate holding surface 1a. The holding stage 1 is rotated about the axis CL as the center by the stage rotating device 3, whereby the wafer W is rotated about the axis CL as the center. The liquid supply nozzle 18 supplies liquid to the center of the wafer W and forms a liquid film on the top of the wafer W. Then, the actuator 12 moves the entire polishing head 8 including the pressing member 5 toward the wafer W, and the pressing member 5 presses the polishing surface of the polishing tape T against the peripheral edge of the wafer W. The pressing member 5 presses the polishing tape T against the peripheral edge of the wafer W in a direction perpendicular to the upper surface of the wafer W. The peripheral portion of the wafer W is polished by the relative movement of the polishing belt T and the wafer W in the presence of liquid. During the polishing of the wafer W, the polishing tape T is conveyed in its longitudinal direction at a predetermined speed.

During the polishing of the wafer W, the displacement sensor 30 measures the moving distance of the polishing head 8. The measured value of the moving distance of the polishing head 8 is transmitted to the action control unit 34. The action control unit 34 determines the polishing end point of the time when the measured value of the moving distance of the polishing head 8 reaches the preset target value. After the operation control unit 34 determines the polishing end point, it issues an instruction to the actuator 12 to separate the polishing head 8 from the wafer W, and then stops the stage rotating device 3. The actuator 12 is an embodiment composed of a combination of a ball screw mechanism and a servo motor. The motion control unit 34 can obtain the moving distance of the polishing head 8 from the screw pitch of the ball screw mechanism and the number of rotations of the servo motor. Therefore, the displacement sensor 30 may be omitted.

FIG. 3 is an enlarged view of the polishing head 8. The polishing head 8 is provided with: a sequential unwinding shaft 21 for unwinding the abrasive tape T in sequence; a winding reel 22 for winding the abrasive tape T; a positioning roller 33 supporting the abrasive tape T and a plurality of guide rollers 35, 36; and in its length The belt feeding mechanism 25 that sends out the abrasive belt T in the direction. The abrasive belt T extends from the unwinding shaft 21 to the winding shaft 22 via the guide roller 35, the positioning roller 33, the pressing member 5, the guide roller 36, and the belt feeding mechanism 25 in order.

The polishing head 8 further has a base 40 that holds the positioning roller 33, the guide rollers 35, 36, the pressing member 5, the belt feeding mechanism 25, the unwinding shaft 21, and the winding reel 22 in sequence. The sensor target 28 is fixed to the base 40. The pressing member 5 is fixed to the lower part of the base 40 and protrudes downward from the lower part of the base 40. The pressing member 5 has: a pressing surface 5A parallel to the substrate holding surface 1a; and an inclined surface 5B connected to the inner end 5c of the pressing surface 5A. The pressing surface 5A constitutes the bottom surface of the pressing member 5 and is located below the base 40.

The belt feeding mechanism 25 has: a belt feeding roller 25A; a belt feeding motor 25B connected to the belt feeding roller 25A; and a nip roller 25C that presses the grinding tape T against the belt feeding roller 25A. The pinch roller 25C is urged toward the tape feed roller 25A by a urging device (for example, a spring) not shown. The polishing belt T is sandwiched between the belt feed roller 25A and the pinch roller 25C. The tape feed roller 25A and the nip roller 25C are rotatably supported on the base 40. The tape feeding motor 25B is fixed to the base 40. When the tape feed roller 25A is rotated by the tape feed motor 25B, the polishing tape T is sent out in the longitudinal direction. That is, the polishing tape T is sent out in the direction indicated by the arrow in FIG. 3, and moves from the unwinding shaft 21 to the winding reel 22 in sequence. During the polishing of the wafer W, the polishing tape T is fed out at a predetermined speed by the tape feeding mechanism 25.

The positioning roller 33, the guide rollers 35, 36, the unwinding shaft 21, and the winding and winding shaft 22 are rotatably held on the base 40. Since the pressing member 5 is also fixed to the base 40, the relative positions of the pressing member 5 to the positioning roller 33, the guide rollers 35, 36, the unwinding shaft 21, and the winding shaft 22 in sequence are fixed. The positioning roller 33 and the guide roller 36 are arranged adjacent to the pressing member 5. At least a part of the positioning roller 33 is located outside the inner edge 5c of the pressing surface 5A in the radial direction of the substrate holding surface 1a (that is, in the radial direction of the wafer W).

The positioning roller 33 functions as a guide roller and is used to define (fix) the relative position of the polishing tape T to the inclined surface 5B of the pressing member 5. The position of the polishing tape T along the inclined surface 5B is fixed by the positioning roller 33. The inclined surface 5B of the pressing member 5 faces the axis CL of the substrate holding surface 1 a (refer to FIG. 2 ), and constitutes the inner surface of the pressing member 5. The distance between the positioning roller 33 and the upper end of the inclined surface 5B is shorter than the distance between the guide rollers 35, 36 and the upper end of the inclined surface 5B. In other words, the positioning roller 33 is arranged at a position closest to the inclined surface 5B than the guide rollers 35, 36.

The unwinding shaft 21 and the winding reel 22 are connected to two tension motors 45 and 46 respectively. These tension motors 45 and 46 are fixed to the base 40. The tension motors 45 and 46 are configured to apply torque in the opposite direction to the unwinding shaft 21 and the winding shaft 22 in order, whereby the polishing tape T can be given tension.

In order to prevent the polishing tape T supported by the pressing member 5 and the positioning roller 33 from slackening, during the polishing of the wafer W, the tension of the polishing tape T needs to be maintained to a certain degree. In this embodiment, the unwinding shaft 21, the winding reel 22, and the pressing member 5 are supported on the common base 40 in sequence. In particular, since the pressing member 5 is fixed to the base 40, even if the tension of the polishing tape T is increased, the relative position of the pressing member 5 to the base 40 will not change. Therefore, the actuator 12 does not affect the tension of the polishing belt T, and can accurately apply the preset polishing load to the pressing member 5.

FIG. 4 is a perspective view of the pressing member 5. The inclined surface 5B extends upward from the inner end edge 5c of the pressing surface 5A. Both the pressing surface 5A and the inclined surface 5B are flat surfaces. The angle α formed by the pressing surface 5A and the inclined surface 5B is an acute angle. More specifically, the angle α is in the range of 20 to 90 degrees, and preferably in the range of 30 to 70 degrees. The pressing member 5 is made of metal such as stainless steel, or hard resin.

FIG. 5 is an enlarged side view showing the pressing member 5 and the positioning roller 33. The positioning roller 33 is located directly above the inclined surface 5B, and is arranged close to the inclined surface 5B. At least a part of the positioning roller 33 is located outside the inner edge 5c of the pressing surface 5A in the radial direction of the substrate holding surface 1a (that is, the radial direction of the wafer W). The positioning roller 33 guides the polishing tape T so that the polishing tape T extends along the inclined surface 5B. The relative position of the polishing belt T to the inclined surface 5B is fixed by the positioning roller 33.

The angle β of the abrasive belt T extending between the positioning roller 33 and the pressing member 5 to the pressing surface 5A is an acute angle. The angle β is not limited to an acute angle. The angle β may be as shown in FIG. 5, which is the same as the angle α formed by the pressing surface 5A and the inclined surface 5B, or may be smaller than the angle α as shown in FIG. 6, or as shown in FIG. As shown, it is larger than the angle α. The embodiment shown in FIGS. 5 and 6 is that the positioning roller 33 is arranged at a position where the back side of the polishing belt T contacts the inclined surface 5B, and the embodiment shown in FIG. 7 is that the positioning roller 33 is arranged on the back side of the polishing belt T from The position where the inclined surface 5B is away.

8A to 8C are diagrams showing how the peripheral edge of the wafer is polished. The wafer W has a structure in which a pattern wafer W1 formed with a pattern and a support wafer W2 composed of a silicon wafer or the like are bonded by an oxide film or an adhesive (indicated by the symbol 200). As shown in FIG. 8A, the polishing tape T is pressed against the peripheral edge of the wafer W by the pressing member 5. The direction in which the pressing member 5 presses the polishing tape T is a direction perpendicular to the substrate holding surface 1a. As shown in FIG. 8B, the polishing tape T removes the entire peripheral edge of the pattern wafer W1, and further removes a part of the peripheral edge of the support wafer W2.

In the polishing of the wafer W, the polishing tape T is pressed against the wafer W only by the pressing surface 5A constituting the bottom surface of the pressing member 5, and the inclined surface 5B of the pressing member 5 does not press the polishing tape T against the wafer W. The pressing surface 5A of the pressing member 5 is parallel to the substrate holding surface 1a, and the moving direction of the pressing member 5 is perpendicular to the substrate holding surface 1a. Since the substrate holding surface 1a is parallel to the upper surface of the wafer W, the pressing surface 5A of the pressing member 5 is also parallel to the upper surface of the wafer W on the substrate holding surface 1a. Therefore, as shown in FIG. 8C, the polishing tape T can form a pit 100 with a right-angle cross-sectional shape on the peripheral edge of the wafer W as the pressing member 5 moves.

As shown in FIGS. 8A and 8B, since the substrate holding surface 1 a has the same size as the wafer W, the polishing load applied to the wafer W from the pressing member 5 via the polishing tape T is blocked by the holding stage 1. Therefore, the wafer W is not bent downward. As a result, the pressing member 5 presses the polishing tape T in a direction perpendicular to the upper surface of the wafer W, and the polishing tape T can form pits with a right-angle cross-sectional shape on the periphery of the wafer W.

During the polishing of the wafer W, since the polishing tape T is sequentially sent out in the longitudinal direction by the tape feeding mechanism 25 (refer to FIG. 3 ), the polishing tape T does not become clogged. Therefore, the polishing rate (removal rate) of the wafer W is stable.

Fig. 9 is a schematic diagram showing another embodiment of the polishing apparatus. Since the configuration and operation of the present embodiment, which are not specifically described, are the same as the embodiment described with reference to FIGS. 1A to 8C, the repeated description thereof will be omitted.

The unwinding shaft 21 and the winding reel 22 in this embodiment are arranged away from the polishing head 8 in order. More specifically, the sequential unwinding shaft 21 and the winding reel 22 are rotatably supported by a reel suport 50 disposed away from the polishing head 8. The unwinding shaft 21 and the rewinding shaft 22 are arranged on the outside of the base 40 of the polishing head 8 and are located at the same height as the polishing head 8. The polishing head 8 includes a first guide roller 51 and a second guide roller 52 that are rotatably supported on the upper portion of the base 40. The first guide roller 51 is located at the same height as the sequential unwinding shaft 21, and the second guide roller is located at the same height as the winding shaft 22. Therefore, the polishing tape T extends from the sequential unwinding shaft 21 to the first guide roller 51 in the lateral direction. Similarly, the polishing belt T extends from the second guide roller 52 to the winding shaft 22 in the lateral direction.

The tension motors 45 and 46 are fixed to the reel bracket 50. The position of the reel support 50 is fixed, and the positions of the unwinding reel 21 and the reeling reel 22 in sequence are also fixed. The actuator 12 moves the polishing head 8 including the first guide roller 51, the second guide roller 52, the positioning roller 33, and the pressing member 5 in a direction perpendicular to the substrate holding surface 1a (the upper surface of the wafer W). In addition, The positions of the unwinding reel 21 and the reeling reel 22 in sequence remain unchanged.

When torques in opposite directions are applied to the unwinding shaft 21 and the rewinding shaft 22 in order by the two tension motors 45, 46, tension is applied to the polishing tape T. The tension of the polishing tape T generates a force that causes the polishing head 8 to approach the unwinding shaft 21 and the winding shaft 22 in sequence. The direction of the force approaching the polishing head 8 is perpendicular to the direction in which the actuator 12 moves the polishing head 8. Therefore, the force (grinding load) imparted by the actuator 12 to the pressing member 5 of the polishing head 8 hardly affects the tension of the polishing tape T. As a result, the actuator 12 does not affect the tension of the polishing belt T, and can accurately apply the preset polishing load to the pressing member 5.

Fig. 10 is a schematic diagram showing still another embodiment of the polishing apparatus. Since the configuration and operation of the present embodiment, which are not specifically described, are the same as the embodiment described with reference to FIGS. 1A to 8C, the repeated description thereof will be omitted. In the entire polishing head 8 of this embodiment, the polishing head 8 shown in FIG. 2 is set in a state of being inclined by 90 degrees. The entire polishing head 8 including the pressing member 5 and the positioning roller 33 is located outside the substrate holding surface 1a. More specifically, the polishing head 8 is located outside the substrate holding surface 1a in the radial direction of the substrate holding surface 1a, and the pressing member 5 is arranged at a position slightly higher than the substrate holding surface 1a. The pressing member 5 is fixed to the inner side of the base 40 and protrudes from the inner side of the base 40 toward the substrate holding surface 1a.

The actuator 12 is located outside the polishing head 8 in the radial direction of the substrate holding surface 1a. The actuator 12 is arranged to move the polishing head 8 in the radial direction of the substrate holding surface 1 a (that is, the radial direction of the wafer W). In other words, the actuator 12 can move the polishing head 8 in a direction toward and away from the axis CL of the substrate holding surface 1a. Therefore, the pressing member 5 can press the polishing tape T against the peripheral edge of the wafer W in a direction toward the center of the wafer W.

FIG. 11 is an enlarged view of the polishing head 8 shown in FIG. 10. The pressing surface 5A of the pressing member 5 is perpendicular to the substrate holding surface 1a, and the inclined surface 5B is inclined upward from the lower edge 5d of the pressing surface 5A. The angle formed by the pressing surface 5A and the inclined surface 5B, and the angle between the polishing tape T extending between the positioning roller 33 and the pressing member 5 and the pressing surface 5A are the same as the above-mentioned embodiment. The highest point of the positioning roller 33 is higher than the end edge 5d below the pressing surface 5A. The pressing surface 5A of this embodiment faces the axis CL of the substrate holding surface 1a and is parallel to the axis CL.

Fig. 12 is a perspective view of the pressing member 5 shown in Fig. 11. As shown in FIG. 12, the pressing surface 5A is curved with the same curvature as the curvature of the peripheral edge portion of the wafer W. Therefore, when the pressing surface 5A presses the polishing tape T against the peripheral edge of the wafer W, the polishing tape T bends along the peripheral edge of the wafer W. Therefore, the reason why the pressing surface 5A is curved along the peripheral edge of the wafer W is to increase the contact area between the polishing tape T and the peripheral edge of the wafer W.

FIGS. 13A to 13C are diagrams showing how the polishing tape T is pressed against the peripheral edge of the wafer W by the pressing member 5 shown in FIG. 11. As shown in FIG. 13A, the polishing tape T is pressed against the peripheral edge of the wafer W by the pressing member 5. The direction in which the pressing member 5 presses the polishing tape T is a direction parallel to the substrate holding surface 1a (that is, a direction parallel to the upper surface of the wafer W), and is a direction toward the axis CL of the substrate holding surface 1a (that is, , Toward the center of wafer W). As shown in FIG. 13A, at the beginning of polishing, the polishing tape T only contacts the patterned wafer W1 of the wafer W.

As shown in FIG. 13B, as the polishing progresses, the polishing tape T contacts both the pattern wafer W1 and the supporting wafer W2, and the peripheral portions of the two wafers W1 and W2 are removed. In the same manner as in the above embodiment, during polishing of the wafer W, the polishing tape T is pressed against the wafer W only by the pressing surface 5A constituting the inner surface of the pressing member 5, and the inclined surface 5B constituting the bottom surface of the pressing member 5 The polishing tape T is not pressed against the wafer W. The pressing surface 5A of the pressing member 5 is perpendicular to the substrate holding surface 1a, and the moving direction of the pressing member 5 is parallel to the substrate holding surface 1a. Since the substrate holding surface 1a is substantially parallel to the upper surface of the wafer W, as shown in FIG. 13C, as the pressing member 5 moves, the polishing tape T can form a right-angled cross-sectional recess on the periphery of the wafer W. Pit 100.

Fig. 14 is a schematic diagram showing still another embodiment of the polishing apparatus. Since the configuration and operation of the present embodiment, which are not specifically described, are the same as those of the embodiment described with reference to FIGS. 10 to 13C, the repetitive description thereof will be omitted. In the entire polishing head 8 of this embodiment, the polishing head 8 shown in FIG. 9 is set to be inclined at 90 degrees.

The unwinding shaft 21 and the winding reel 22 in this embodiment are arranged away from the polishing head 8 in order. More specifically, the sequential unwinding shaft 21 and the rewinding shaft 22 are rotatably supported by the reel holder 50 disposed away from the polishing head 8. The unwinding shaft 21 and the rewinding shaft 22 are arranged above the polishing head 8 in sequence. The polishing head 8 includes a first guide roller 51 and a second guide roller 52 that are rotatably supported on the outer side of the base 40. The first guide roller 51 is located below the unwinding shaft 21 in sequence, and the second guide roller is located below the winding shaft 22. Therefore, the polishing tape T extends upward from the unwinding shaft 21 toward the first guide roller 51 in order. Similarly, the polishing tape T extends upward from the second guide roller 52 toward the winding shaft 22.

The tension motors 45 and 46 are fixed to the reel bracket 50. The position of the reel support 50 is fixed, and the positions of the unwinding reel 21 and the reeling reel 22 in sequence are also fixed. The actuator 12 moves the polishing head 8 including the first guide roller 51, the second guide roller 52, the positioning roller 33, and the pressing member 5 in a direction parallel to the substrate holding surface 1a (the upper surface of the wafer W). In addition, The positions of the unwinding reel 21 and the reeling reel 22 in sequence remain unchanged.

When torques in opposite directions are applied to the unwinding shaft 21 and the rewinding shaft 22 in order by the two tension motors 45, 46, tension is applied to the polishing tape T. The tension of the polishing tape T generates a force that causes the polishing head 8 to approach the unwinding shaft 21 and the winding shaft 22 in sequence. The direction of the force approaching the polishing head 8 is perpendicular to the direction in which the actuator 12 moves the polishing head 8. Therefore, the force (grinding load) imparted by the actuator 12 to the pressing member 5 of the polishing head 8 hardly affects the tension of the polishing tape T. As a result, the actuator 12 does not affect the tension of the polishing belt T, and can accurately apply the preset polishing load to the pressing member 5.

The above-mentioned embodiments are described for the purpose of being able to carry out the present invention by those with ordinary knowledge in the technical field to which the present invention belongs. Those skilled in the art can of course make various modifications of the above-mentioned embodiments, and the technical idea of the present invention can also be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but should be interpreted in the widest range based on the technical ideas defined by the scope of the patent application. [Industrial availability]

The present invention can be used in a polishing apparatus for forming pits having a right-angle cross-sectional shape on the peripheral edge of a substrate such as a bonded wafer.

1: Keep the stage 1a: substrate holding surface 1b: opening 1c: carrier axis 3: Carrier rotating device 5: Compression member 5A: pressure surface 5B: Inclined surface 5c: inner edge 5d: lower edge 8: Grinding head 12: Actuator 15: Vacuum line 18: Liquid supply nozzle 21: Unwind the scrolls in order 22: Rewinding reel 25: Belt delivery mechanism 25A: Feeding roller 25B: Feeding motor 25C: Clamping roller 28: Sensor target 30: Displacement sensor 33: positioning roller 34: Action Control Department 34a: Memory device 34b: Processing device 35, 36: guide roller 40: Pedestal 45, 46: Tension motor 50: reel holder 51: The first guide roller 52: The second guide roller 100: Pit 500: Grindstone 505: pit 510: pit 600: Grinding belt 601: Compression member 610: Slanted Face CL: axis T: Grinding belt W: Wafer W1: Patterned wafer W2: Support wafer

Fig. 1A is an enlarged cross-sectional view showing the peripheral edge of the substrate. Fig. 1B is an enlarged cross-sectional view showing the peripheral portion of the substrate. Fig. 2 is a schematic diagram showing an embodiment of the polishing device. Figure 3 is an enlarged view of the polishing head. Figure 4 is a perspective view of the pressing member. Figure 5 is an enlarged side view showing the pressing member and the positioning roller. Fig. 6 is a side view showing another example of the arrangement of the pressing member and the positioning roller. Fig. 7 is a side view showing still another example of the arrangement of the pressing member and the positioning roller. FIG. 8A is a diagram showing the state of polishing the peripheral edge of the wafer. FIG. 8B is a diagram showing the situation of polishing the peripheral edge of the wafer. FIG. 8C is a diagram showing the state of polishing the peripheral edge of the wafer. Fig. 9 is a schematic diagram showing another embodiment of the polishing apparatus. Fig. 10 is a schematic diagram showing still another embodiment of the polishing apparatus. Fig. 11 is an enlarged view of the polishing head shown in Fig. 10. Fig. 12 is a perspective view of the pressing member shown in Fig. 11. FIG. 13A is a diagram showing a situation in which the polishing tape is pressed against the peripheral edge of the wafer by the pressing member shown in FIG. 11. FIG. 13B is a diagram showing a situation in which the polishing tape is pressed against the peripheral edge of the wafer by the pressing member shown in FIG. 11. FIG. 13C is a cross-sectional view of a wafer in which pits with a right-angle cross-sectional shape are formed at the peripheral edge. Fig. 14 is a schematic diagram showing still another embodiment of the polishing apparatus. Fig. 15 is a schematic diagram showing a conventional polishing device equipped with a grindstone. FIG. 16 is a cross-sectional view of a wafer in which pits with a right-angle cross-sectional shape are formed on the periphery. Fig. 17A is a diagram showing the wafer. FIG. 17B is a diagram showing the situation when the wafer is being polished. FIG. 17C is a cross-sectional view of a wafer in which pits with a right-angle cross-sectional shape are formed on the periphery. Fig. 18A is a schematic diagram showing a conventional polishing device using a polishing belt. 18B is a cross-sectional view showing the peripheral edge of the wafer polished using the polishing device shown in FIG. 18A.

1: Keep the stage

1a: substrate holding surface

5: Compression member

5A: pressure surface

5B: Inclined surface

5c: inner edge

8: Grinding head

12: Actuator

21: Unwind the scrolls in order

22: Rewinding reel

25: Belt delivery mechanism

25A: Feeding roller

25B: Feeding motor

25C: Clamping roller

28: Sensor target

33: positioning roller

35, 36: guide roller

40: Pedestal

45, 46: Tension motor

T: Grinding belt

W: Wafer

Claims (12)

A grinding device equipped with: The holding stage has a substrate holding surface for holding the substrate; A polishing head having a pressing member for pressing the polishing tape against the peripheral edge of the substrate on the substrate holding surface; and An actuator that moves the polishing head to the substrate holding surface in a vertical direction; The pressing member has: a pressing surface which is parallel to the substrate holding surface; and an inclined surface which is connected to the inner end edge of the pressing surface; the angle formed by the pressing surface and the inclined surface is an acute angle , The polishing head is provided with a positioning roller that defines the relative position of the polishing belt to the inclined surface, and the angle of the polishing belt extending between the positioning roller and the pressing member to the pressing surface is an acute angle. The polishing device according to claim 1, wherein the relative position of the positioning roller and the pressing member is fixed. The polishing device according to claim 1 or 2, wherein the angle of the polishing belt extending between the positioning roller and the pressing member to the pressing surface is in the range of 30 to 90 degrees. The polishing device according to claim 1 or 2, wherein the aforementioned polishing head further has: Unwind the reels in sequence, which releases the aforementioned abrasive belts in sequence; The winding shaft, which winds up the aforementioned abrasive belt; and The base holds the positioning roller, the pressing member, the unwinding shaft in sequence, and the winding and winding shaft. The grinding device according to claim 1 or 2, wherein the aforementioned grinding device is further equipped with: Unwind the reels in sequence, which unwind the aforementioned abrasive tapes in sequence; and Winding reel, which winds up the aforementioned abrasive belt; The sequential unwinding shaft and the rewinding shaft are arranged at the same height as the polishing head. The polishing apparatus according to claim 1 or 2, wherein the substrate holding surface is the same size as the substrate or larger than the substrate. A grinding device equipped with: The holding stage has a substrate holding surface for holding the substrate; A polishing head having a pressing member for pressing the polishing tape on the peripheral edge of the substrate on the substrate holding surface; and An actuator that moves the polishing head in a direction parallel to the substrate holding surface; The pressing member has: a pressing surface perpendicular to the substrate holding surface; and an inclined surface connected to the lower end edge of the pressing surface; the angle formed by the pressing surface and the inclined surface is an acute angle, The polishing head is provided with a positioning roller that defines the relative position of the polishing belt to the inclined surface, and the angle of the polishing belt extending between the positioning roller and the pressing member to the pressing surface is an acute angle. The polishing device according to claim 7, wherein the relative position of the positioning roller and the pressing member is fixed. The polishing device according to claim 7 or 8, wherein the angle of the polishing belt extending between the positioning roller and the pressing member to the pressing surface is in the range of 30 to 90 degrees. The polishing device according to claim 7 or 8, wherein the aforementioned polishing head further has: Unwind the reels in sequence, which releases the aforementioned abrasive belts in sequence; The winding shaft, which winds up the aforementioned abrasive belt; and The base holds the positioning roller, the pressing member, the unwinding shaft in sequence, and the winding and winding shaft. The grinding device according to claim 7 or 8, wherein the aforementioned grinding device is further equipped with: Unwind the reels in sequence, which unwind the aforementioned abrasive tapes in sequence; and Winding reel, which winds up the aforementioned abrasive belt; The aforementioned unwinding shaft and the aforementioned rewinding shaft are arranged above the grinding head. The polishing apparatus according to claim 7 or 8, wherein the substrate holding surface is the same size as the substrate or larger than the substrate.

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