Polishing head and polishing device

Abstract

To provide a polishing head capable of controlling a substrate polishing rate by preventing an edge of a polishing tape from unintentionally coming into contact with a substrate such as a wafer.SOLUTION: A polishing head 10 comprises a pressing mechanism 12 for pressing a polishing tape 2 against a substrate W, and a tape hook 40 for limiting movement of an edge of the polishing tape 2 in the direction of being headed toward the substrate W. The tape hook 40 has a tape positioning surface 47 facing a polishing surface of the edge of the polishing tape 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a polishing head for pressing a polishing tape against a substrate such as a wafer, and also to a polishing apparatus for polishing a substrate with such a polishing head. [Background technology]

[0002] In recent years, devices such as memory circuits, logic circuits, and image sensors (e.g., CMOS sensors) have become increasingly highly integrated. During the processes used to fabricate these devices, foreign particles such as particles and dust can adhere to the devices. Foreign particles adhering to devices can cause short circuits between wiring and circuit malfunctions. Therefore, in order to improve device reliability, it is necessary to clean wafers on which devices are formed and remove foreign particles from the wafer.

[0003] Foreign matter such as the fine particles and dust particles mentioned above can also adhere to the backside (non-device side) of the wafer. If such foreign matter adheres to the backside of the wafer, the wafer moves away from the stage reference surface of the exposure tool, causing the front side of the wafer to tilt relative to the stage reference surface, resulting in patterning deviation and focal length deviation. To prevent such problems, it is necessary to remove foreign matter adhered to the backside of the wafer.

[0004] Therefore, as shown in Figures 15 and 16, a polishing apparatus is used that polishes the backside of a wafer with a polishing tape. Figure 15 is a top view of a conventional polishing apparatus, and Figure 16 is a side view of the conventional polishing apparatus shown in Figure 15. In the polishing apparatus, a plurality of rollers 500 hold the peripheral edge of a wafer W, and these rollers 500 themselves rotate to rotate the wafer W. A polishing tape 502 is disposed on the backside of the wafer W. A predetermined tension is applied to the polishing tape 502 as it advances in the direction indicated by arrow Z.

[0005] The plurality of polishing heads 505 are arranged in the diameter direction of the wafer W, and these polishing heads 505 press the polishing tape 502 against the back surface of the wafer W, thereby polishing the back surface of the wafer W. The polishing tape 502 pressed against the back surface of the wafer W can remove foreign matter from the back surface of the wafer W.

[0006] 17 is a perspective view of the polishing head 505. As shown in Fig. 17, the polishing head 505 has a pressing member 512 that presses the polishing tape 502 against the back surface of the wafer W. This pressing member 512 comes into contact with the center of the polishing tape 502 in the width direction of the polishing tape 502, and presses the polishing tape 502 up toward the wafer W. The polishing tape 502 receives a pressing force from the pressing member 512 and can polish the wafer W. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-122895 Summary of the Invention [Problem to be solved by the invention]

[0008] However, because the polishing tape 502 is flexible but not stretchable, the edge of the polishing tape 502 that is not pressed by the pressing member 512 also follows the center of the polishing tape 502 and lifts up, unintentionally contacting the wafer W. The edge of the polishing tape 502, indicated by the symbol R in FIG. 17, is an area that is not pressed by the pressing member 512, but it contacts the wafer W and slightly polishes the wafer W. Because the polishing load cannot be controlled on the edge of the polishing tape 502 that is not pressed by the pressing member 512, the polishing rate of the portion of the wafer W polished by the edge of the polishing tape 502 becomes unstable. As a result, the polishing head 505 may not be able to uniformly polish the target area of ​​the wafer W.

[0009] Therefore, the present invention provides a polishing head that can prevent the edge of the polishing tape from unintentionally contacting a substrate such as a wafer and can control the removal rate of the substrate.The present invention also provides a polishing apparatus equipped with such a polishing head. [Means for solving the problem]

[0010] In one aspect, a polishing head for polishing a substrate is provided, comprising a pressing mechanism for pressing a polishing tape against the substrate and a tape hook for limiting movement of the edge of the polishing tape in a direction toward the substrate, the tape hook having a tape positioning surface facing the polishing surface of the edge of the polishing tape.

[0011] In one aspect, the tape hook is located adjacent to the pressing mechanism. In one embodiment, the tape hook is a plurality of tape hooks arranged on both sides of the pressing mechanism. In one embodiment, the plurality of tape hooks each have a plurality of tape positioning surfaces that face the polishing surfaces of both edge portions of the polishing tape. In one aspect, the pressing mechanism is a pressing member for pressing the polishing tape against the substrate, and the polishing head further includes a pressing member holder for holding the pressing member, and the distance from a reference surface in the pressing member holder to the end face of the tape hook is shorter than the distance from the reference surface to the tape pressing surface of the pressing member. In one aspect, the tape hook has a protrusion that protrudes toward the pressing member, one side of the protrusion forming the tape positioning surface and the opposite side of the protrusion forming the end surface of the tape hook. In one embodiment, the protrusion is located between the substrate and the edge of the polishing tape. In one embodiment, the tape hook and the pressing mechanism are movable together.

[0012] In one aspect, a polishing apparatus is provided, comprising a substrate holder for holding a substrate and the polishing head described above. [Effects of the Invention]

[0013] The edge of the polishing tape is prevented from coming into contact with the substrate by the tape hook, thereby preventing the edge of the polishing tape from unintentionally polishing the substrate. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing an embodiment of a polishing head for polishing a wafer, which is an example of a substrate, by pressing a polishing tape, which is an example of a polishing tool, against the surface of the wafer. [Figure 2] FIG. 2 is a cross-sectional view of the polishing head shown in FIG. [Figure 3] FIG. 1 is a side view showing one embodiment of a tape hook. [Figure 4] 4 is a cross-sectional view showing a polishing tape supported by a pressing member and a tape hook. FIG. [Figure 5] FIG. 10 is a side view illustrating one embodiment of a tape hook arrangement. [Figure 6] FIG. 10 is a side view showing another embodiment of the arrangement of tape hooks. [Figure 7] FIG. 10 is a perspective view showing another embodiment of the polishing head. [Figure 8] FIG. 10 is a side view illustrating one embodiment of a tape hook arrangement. [Figure 9] FIG. 10 is a side view showing another embodiment of the arrangement of tape hooks. [Figure 10] FIG. 10 is a side view showing yet another embodiment of the arrangement of tape hooks. [Figure 11] 1 is a side view showing an embodiment of a polishing apparatus. [Figure 12] FIG. 12 is a top view of the polishing apparatus shown in FIG. [Figure 13] FIG. 1 is a perspective view showing an embodiment of a polishing head equipped with a fluid pressing portion. [Figure 14] FIG. 10 is a perspective view showing another embodiment of a polishing head provided with a fluid pressing portion. [Figure 15] FIG. 1 is a top view of a conventional polishing apparatus. [Figure 16] FIG. 16 is a side view of the conventional polishing apparatus shown in FIG. [Figure 17] FIG. 1 is a perspective view of a conventional polishing head. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing one embodiment of a polishing head 10 for polishing a wafer W, which is an example of a substrate, by pressing a polishing tape 2, which is an example of a polishing tool, against the surface of the wafer W, which is an example of a substrate, and Fig. 2 is a cross-sectional view of the polishing head 10 shown in Fig. 1. The polishing head 10 of this embodiment is disposed below the wafer W and the polishing tape 2, and is disposed so as to press the polishing tape 2 against the back surface of the wafer W from the back side thereof.

[0016] The polishing head 10 includes a pressing member 12 as a pressing mechanism for pressing the polishing tape 2 against the wafer W, an actuator 15 that applies a pressing force to the pressing member 12 by moving the pressing member 12 in a predetermined pressing direction indicated by an arrow CL, and a housing 18 in which the actuator 15 is disposed. The actuator 15 includes a movable shaft 16 connected to the pressing member 12, and a partition film (diaphragm) 25 that forms a pressure chamber 20 between the end of the movable shaft 16 and the housing 18. The movable shaft 16 and the partition film 25 are disposed within the housing 18.

[0017] The polishing head 10 further includes a pressing member holder 30 that holds the pressing member 12. The pressing member holder 30 is connected to the movable shaft 16 and can move integrally therewith. The pressing member 12 is annular as a whole, and is removably held by the pressing member holder 30. The pressing member holder 30 has a fitting groove (not shown) into which the pressing member 12 fits. The annular pressing member 12 is hung on the pressing member holder 30 in an elastically deformed state while fitting into the fitting groove. The pressing member 12 of this embodiment has two tape pressing surfaces 12A and 12B for pressing the polishing tape 2 against the wafer W.

[0018] The pressing member 12 is made of an elastic material. Examples of materials that can be used to form the pressing member 12 include rubbers such as fluororubber, silicone rubber, and ethylene propylene diene rubber. The cross section of the pressing member 12 is circular. The pressing member 12 may be an O-ring. In this embodiment, the pressing member holder 30 has protrusions 30b and 30c on its side surface. The pressing member 12 is supported by the protrusions 30b and 30c in an elastically deformed state.

[0019] However, the pressing member 12 is not limited to this embodiment and may have other shapes or be made of other materials. For example, the pressing member 12 may have only one tape pressing surface for pressing the polishing tape 2 against the wafer W. In another example, instead of being annular, the pressing member 12 may have the shape of a linearly extending blade or a curved blade.

[0020] As shown in FIG. 2, the movable shaft 16 is movable in its axial direction within the housing 18, and the movable shaft 16 can raise the pressing member 12 in the pressing direction indicated by the arrow CL. The pressing member 12 faces the back side of the polishing tape 2. When the movable shaft 16 raises the pressing member 12 in the pressing direction indicated by the arrow CL, the pressing member 12 comes into contact with the back side of the polishing tape 2. The pressing member 12 presses the polishing surface of the polishing tape 2 against the back side of the wafer W, polishing the back side of the wafer W with the polishing tape 2. During polishing of the wafer W, the back side of the polishing tape 2 is supported by the pressing member 12. The back side of the polishing tape 2 is the surface opposite the polishing surface having abrasive grains. During polishing of the wafer W, the polishing tape 2 is fed in its longitudinal direction at a predetermined speed.

[0021] In this embodiment, the movable shaft 16 is configured as a ball spline shaft. A ball spline nut 32 is disposed within the housing 18, and the movable shaft 16 is supported by the ball spline nut 32 so as to be movable in the axial direction of the movable shaft 16. In one embodiment, the movable shaft 16 may be supported on the inner surface of the housing 18 so as to be movable.

[0022] The housing 18 includes a housing main body 18A having a space formed therein for accommodating the movable shaft 16, and a lid 18B that closes the space. The lid 18B is detachably fixed to the housing main body 18A with screws (not shown). The actuator 15, which generates a pressing force for pressing the polishing tape 2 against the wafer W, includes the movable shaft 16 and a partition wall film 25. The partition wall film 25 is in contact with the end (lower end) of the movable shaft 16, and the edge of the partition wall film 25 is sandwiched between the housing main body 18A and the lid 18B. The partition wall film 25 is only in contact with the movable shaft 16 and is not fixed to the movable shaft 16.

[0023] The partition membrane 25 is made of a flexible material. Examples of materials that can be used to form the partition membrane 25 include chloroprene rubber, fluororubber, and silicone rubber. The pressure chamber 20 is connected to a compressed gas supply line (not shown), and compressed gas (e.g., compressed air) is supplied into the pressure chamber 20 from the compressed gas supply line.

[0024] When polishing the wafer W, compressed gas such as compressed air is supplied into the pressure chamber 20. The pressure of the compressed gas in the pressure chamber 20 acts on the end (lower end) of the movable shaft 16 through the partition membrane 25, causing the movable shaft 16, the pressing member holder 30, and the pressing member 12 to rise. The polishing head 10 may further include a distance sensor that measures the relative movement distance of the movable shaft 16 with respect to the housing 18. When polishing of the wafer W is to be completed, the pressure chamber 20 is opened to the atmosphere, and as a result, the movable shaft 16 and the pressing member 12 descend due to the weight of the movable shaft 16 and the tension of the polishing tape 2.

[0025] A skirt 38 is fixed to the pressing member holder 30. This skirt 38 extends downward from the pressing member holder 30 and surrounds the upper part of the housing 18. In this embodiment, the skirt 38 is cylindrical, but it may have any other shape as long as it can surround the upper part of the housing 18. The skirt 38 can prevent liquids such as pure water used in polishing the wafer W from entering the housing 18.

[0026] 1, during polishing of the wafer W, the polishing tape 2 is fed at a predetermined speed in the longitudinal direction of the polishing tape 2, as indicated by the arrow Z. The pressing member 12 in this embodiment extends obliquely with respect to the longitudinal direction (traveling direction Z) of the polishing tape 2. When polishing the wafer W, the pressing member 12 presses the polishing tape 2 against the wafer W from its back side.

[0027] As shown in FIG. 1, the polishing head 10 has a plurality of tape hooks 40. Each tape hook 40 is detachably attached to the pressing member holder 30 by a screw 41. The tape hooks 40 are configured to limit movement of the edge of the polishing tape 2 in a direction toward the wafer W. More specifically, when the pressing member 12 presses the polishing tape 2 against the wafer W, the tape hooks 40 are configured to prevent the edge of the polishing tape 2 from contacting the wafer W. The pressing member holder 30 has inclined surfaces 30d and 30e that slope downward from the pressing member 12 toward the tape hooks 40.

[0028] The tape hook 40 and the pressing member 12 can move together. That is, the tape hook 40 and the pressing member 12 are moved together toward the wafer W by the actuator 15 shown in FIG. 2. The tape hook 40 is disposed adjacent to the pressing member 12, but is not in contact with the pressing member 12. In this embodiment, the multiple tape hooks 40 are disposed on both sides of the pressing member 12. That is, the multiple tape hooks 40 are disposed on both sides of the polishing tape 2, and limit the movement of both edges of the polishing tape 2 in the direction toward the wafer W.

[0029] FIG. 3 is a side view showing one embodiment of the tape hooks 40. As shown in FIG. 3, each of the tape hooks 40 has a protrusion 45 that protrudes toward the pressing member 12. The protrusion 45 has a tape positioning surface 47 that faces the polishing surface of the edge of the polishing tape 2. One side of the protrusion 45 forms the tape positioning surface 47, and the opposite side of the protrusion 45 forms a flat end surface 48. In this embodiment, the protrusion 45 has a tapered shape, and the tape positioning surface 47 slopes upward toward the pressing member 12. The protrusion 45 is located between the wafer W and the edge of the polishing tape 2. Therefore, the edge of the polishing tape 2 does not contact the wafer W.

[0030] The distance L1 from the reference plane PL in the pressing member holder 30 to each end face 48 of the tape hook 40 is shorter than the distance L2 from the reference plane PL to the tape pressing surfaces 12A and 12B of the pressing member 12. The reference plane PL is an imaginary plane perpendicular to the direction CL in which the pressing member 12 presses the polishing tape 2 against the wafer W. The end face 48 of the tape hook 40 is the end face of the tape hook 40 farthest from the reference plane PL. In the embodiment shown in FIG. 3 , the end face 48 of the tape hook 40 is the top surface of the tape hook 40. In this embodiment, the height of the tape hook 40 from the reference plane PL is shorter than the height of the tape pressing surfaces 12A and 12B of the pressing member 12 from the reference plane PL.

[0031] 4 is a cross-sectional view showing the polishing tape 2 supported by the pressing member 12 and the tape hook 40. As shown in Fig. 4, both edge portions of the polishing tape 2 engage with the tape hooks 40, and the tape hooks 40 fix the height of both edge portions of the polishing tape 2 relative to the pressing member 12. In other words, the center of the polishing tape 2 is lifted by the pressing member 12, but both edge portions of the polishing tape 2 come into contact with the tape positioning surfaces 47 of the tape hooks 40, restricting the upward movement (deformation) of both edge portions of the polishing tape 2.

[0032] As can be seen from FIG. 4 , when viewed from the traveling direction Z of the polishing tape 2, the protrusion 45 of the tape hook 40 is located between the edge of the polishing tape 2 and the wafer W. As a result, both edges of the polishing tape 2 do not contact the wafer W, while the center of the polishing tape 2 is pressed against the wafer W by the pressing member 12. This prevents the edges of the polishing tape 2 from unintentionally polishing the wafer W, while the center of the polishing tape 2 is pressed against the wafer W by the pressing member 12 with a controlled polishing load. The length of the protrusion 45 is not particularly limited, but is a length that allows the tape hook 40 to engage with the edge of the polishing tape 2 and does not interfere with the pressing member 12 pressing the polishing tape 2 against the wafer W, i.e., a length that does not contact the pressing member 12 or the pressing member holder 30. In this specification, the length of the protrusion 45 is the length in a direction perpendicular to the longitudinal direction of the polishing tape 2.

[0033] The number and arrangement of the tape hooks 40 are not limited to the embodiment described with reference to FIGS. 1 to 4 . For example, as shown in the schematic diagram of FIG. 5 , multiple sets of tape hooks 40 may be provided on both sides of the pressing member 12. As shown in FIG. 5 , the lengths of the protrusions 45 of the tape hooks 40 may vary. For example, the length of the protrusions 45 of the tape hooks 40 (the length in a direction perpendicular to the longitudinal direction of the polishing tape 2) may increase according to the distance between the tape hooks 40 and the pressing member 12. In another example, as shown in FIG. 6 , the tape hooks 40 may have a width greater than the length of the protrusions 45. Although not shown, depending on the position and / or shape of the pressing member 12, the tape hooks 40 may be provided on only one side of the pressing member 12. In this case, the tape hooks 40 restrict the movement of only one edge of the polishing tape 2.

[0034] 7 is a perspective view showing another embodiment of the polishing head 10. The configuration and operation of this embodiment, which will not be specifically described, are the same as those of the embodiment described with reference to FIGS. 1 to 6, and therefore, redundant description will be omitted.

[0035] 1 to 6 in that the pressing member 12 has only one tape pressing surface 12A and that two tape hooks 40 are provided on one side of the pressing member 12 and one tape hook 40 is provided on the other side. In this embodiment, too, the tape hooks 40 prevent both edges of the polishing tape 2 from contacting the wafer W, while the center of the polishing tape 2 is pressed against the wafer W by the pressing member 12. Therefore, unintentional polishing of the wafer W by the edges of the polishing tape 2 is prevented, while the center of the polishing tape 2 is pressed against the wafer W by the pressing member 12 with a controlled polishing load.

[0036] The number and arrangement of the tape hooks 40 are not limited to the embodiment shown in FIG. 7 . For example, as shown in the schematic diagram of FIG. 8 , multiple sets of tape hooks 40 may be provided on both sides of the pressing member 12. As shown in FIG. 8 , the lengths of the protrusions 45 of the tape hooks 40 may vary. For example, the length of the protrusions 45 of the tape hooks 40 may increase according to the distance between the tape hooks 40 and the pressing member 12. In another example, as shown in FIG. 9 , one set of tape hooks 40 may be provided on both sides of the pressing member 12. In yet another example, as shown in FIG. 10 , the tape hooks 40 may have a width greater than the length of the protrusions 45. Although not shown, depending on the position and / or shape of the pressing member 12, the tape hooks 40 may be provided on only one side of the pressing member 12.

[0037] Fig. 11 is a side view showing one embodiment of a polishing apparatus, and Fig. 12 is a top view of the polishing apparatus shown in Fig. 11. The polishing apparatus shown in Figs. 11 and 12 includes a substrate holding unit 70 that holds and rotates a wafer W, multiple polishing heads 10A to 10D that polish the first side 5a of the wafer W by bringing polishing tapes 2A and 2B into contact with the first side 5a of the wafer W held by the substrate holding unit 70, a polishing tape supply mechanism 72A that supplies the polishing tape 2A to the polishing heads 10A and 10B and collects the polishing tape 2A from the polishing heads 10A and 10B, and a polishing tape supply mechanism 72B that supplies the polishing tape 2B to the polishing heads 10C and 10D and collects the polishing tape 2B from the polishing heads 10C and 10D.

[0038] The polishing heads 10A and 10C have the same configuration as the polishing head 10 described with reference to Figures 1 to 4, and the polishing heads 10B and 10D have the same configuration as the polishing head 10 described with reference to Figure 7. The polishing tapes 2A and 2B have the same configuration.

[0039] In this embodiment, the first surface 5a of the wafer W is the back surface of the wafer W on which no devices have been formed or are not planned to be formed, i.e., the non-device surface. The second surface 5b of the wafer W opposite the first surface 5a is the surface on which devices have been formed or are planned to be formed, i.e., the device surface. In this embodiment, the wafer W is supported horizontally by the substrate holder 70 with the first surface 5a facing downward.

[0040] The substrate holder 70 includes a plurality of rollers 75A, 75B, 75C, and 75D that can come into contact with the peripheral edge of the wafer W, and a roller rotation device (not shown) for rotating the rollers 75A to 75D at the same speed. In this embodiment, four rollers 75A to 75D are provided, but five or more rollers may also be provided.

[0041] The polishing heads 10A and 10B are supported by a support member 78A, and the polishing heads 10C and 10D are supported by a support member 78B. The polishing heads 10A to 10D are disposed below the wafer W held by the substrate holder 70. The polishing heads 10A to 10D are arranged in the diameter direction of the wafer W. In this embodiment, four polishing heads 10A to 10D are provided, but the number of polishing heads is not limited to this embodiment. In another embodiment, a single polishing head may be provided.

[0042] Since the polishing tape supply mechanisms 72A and 72B have the same configuration, only the polishing tape supply mechanism 72A will be described below. The polishing tape supply mechanism 72A is equipped with a tape supply reel 81 to which one end of the polishing tape 2A is connected, a tape take-up reel 82 to which the other end of the polishing tape 2A is connected, and a plurality of guide rollers 83 that guide the polishing tape 2A in the traveling direction. The tape supply reel 81 and the tape take-up reel 82 are connected to reel motors 86 and 87, respectively.

[0043] By rotating the tape take-up reel 82 in the direction indicated by the arrow, the polishing tape 2A is fed from the tape feed reel 81 to the polishing heads 10A and 10B and then to the tape take-up reel 82. The polishing tape 2A is supplied above the polishing heads 10A and 10B so that the polishing surface of the polishing tape 2A faces the first surface 5a of the wafer W. The reel motor 86 applies a predetermined torque to the tape feed reel 81, thereby applying tension to the polishing tape 2A. The reel motor 87 is controlled to feed the polishing tape 2A at a constant speed. The speed at which the polishing tape 2A is fed can be changed by changing the rotational speed of the tape take-up reel 82.

[0044] In one embodiment, the polishing apparatus may include a tape feeding device that feeds the polishing tape 2A in its longitudinal direction, separate from the tape supply reel 81, the tape take-up reel 82, and the reel motors 86 and 87. In yet another embodiment, the positions of the tape supply reel 81 and the tape take-up reel 82 may be reversed.

[0045] The wafer W is polished as follows. A plurality of rollers 75A to 75D hold the peripheral edge of the wafer W, and the rollers 75A to 75D are rotated to rotate the wafer W. While the polishing tape supply mechanisms 72A and 72B feed the polishing tapes 2A and 2B to the polishing heads 10A to 10D, the pressing members 12 of the polishing heads 10A to 10D press the polishing tapes 2A and 2B against the first surface 5a of the wafer W to polish the first surface 5a of the wafer W.

[0046] The polishing head 10 described with reference to FIGS. 1 to 10 includes a pressing member 12 that contacts the back side of the polishing tape 2. However, in another embodiment, as shown in FIG. 13, the polishing head 10 may include a fluid pressing unit 91 as a pressing mechanism instead of the pressing member 12. FIG. 13 is a perspective view showing one embodiment of the polishing head 10 including the fluid pressing unit 91. The polishing head 10 has the fluid pressing unit 91 with two fluid supply ports 93. These fluid supply ports 93 are connected to a fluid supply line 95. In this embodiment, the actuator 15 shown in FIG. 2 may be omitted.

[0047] The fluid supply port 93 is formed on the end face (top face in FIG. 13 ) of the fluid pressing portion 91 and faces the back side of the polishing tape 2. Similar to the pressing member 12 shown in FIG. 1 , each fluid supply port 93 extends obliquely with respect to the longitudinal direction (travel direction Z) of the polishing tape 2. The fluid supply port 93 is a slit-shaped opening. One end of a fluid supply line 95 is connected to the fluid supply port 93, and the other end is connected to a fluid supply source (not shown). The fluid supply source supplies a fluid, such as a liquid, gas, or a mixture of liquid and gas, to the fluid supply line 95. The fluid passes through the fluid supply line 95, reaches the fluid supply port 93 of the fluid pressing portion 91, and is then ejected from the fluid supply port 93 toward the back side of the polishing tape 2. The fluid jet can press the polishing tape 2 against the wafer W from its back side.

[0048] The tape hooks 40 are disposed on both sides of the two fluid supply ports 93. The configuration, arrangement, and function of the tape hooks 40 are the same as those in the embodiment described with reference to Figures 1 to 6, and therefore, redundant description thereof will be omitted.

[0049] FIG. 14 is a perspective view showing another embodiment of the polishing head 10 equipped with a fluid pressing unit 91. The configuration of this embodiment not specifically described is the same as that of the embodiment shown in FIG. 13, and therefore a duplicated description will be omitted. In the embodiment shown in FIG. 14, the polishing head 10 has a fluid pressing unit 91 equipped with only one fluid supply port 93. Similar to the pressing member 12 shown in FIG. 7, the fluid supply port 93 extends obliquely with respect to the longitudinal direction (travel direction Z) of the polishing tape 2. The fluid supply port 93 is a slit-shaped opening.

[0050] The tape hooks 40 are disposed on both sides of the fluid supply port 93. The configuration, arrangement, and function of the tape hooks 40 are the same as those in the embodiment described with reference to Figures 7 to 10, and therefore, redundant description thereof will be omitted.

[0051] The tape hook 40 described so far is configured to restrict the movement of the edge of the polishing tape 2 in the direction toward the wafer W by physically contacting the polishing surface of the polishing tape 2, but in one embodiment, instead of the tape hook 40, the movement of the edge of the polishing tape 2 in the direction toward the wafer W may be restricted by sucking the back side of the edge of the polishing tape 2 using a vacuum suction port (not shown) formed in the polishing head 10.

[0052] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would be obvious to a person skilled in the art, and the technical concept of the present invention may be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0053] W wafer 2 polishing tapes 2A, 2B Polishing Tape 5a First Side 5b Second Side 10, 10A~10D Polishing head 12 Pressing member 12A, 12B Tape pressing surface 15 Actuators 16 Movable axis 18 Housing 18A housing body 18B Lid 20 Pressure Chamber 25 septum membrane 30 Pressing member holder 30b,30c protrusion 30d,30e sloped surface 32 Ball spline nut 38 Skirt 40 Tape Hooks 45 Protrusion 47 Tape positioning surface 48 End face 70 Board holding part 72A, 72B Polishing tape supply mechanism 78A, 78B Support member 81 Tape unwinding reel 82 Tape take-up reel 83 Guide Roller 86,87 Reel motor 91 Fluid pressing section 93 Fluid supply port 95 Fluid Supply Line

Claims

1. A polishing head for polishing a substrate, comprising: a pressing member that presses the polishing tape against the substrate; a tape hook for limiting movement of an edge of the polishing tape toward the substrate; the tape hook has a tape positioning surface that faces the polishing surface of the edge of the polishing tape; the tape hook has a protruding portion that protrudes toward the pressing member, A polishing head, wherein when the pressing member presses the polishing tape against the substrate, the protrusion is positioned between the substrate and an edge of the polishing tape.

2. The polishing head of claim 1 , wherein the tape hook is disposed adjacent to the pressing member.

3. A polishing head for polishing a substrate, comprising: a pressing mechanism that presses the polishing tape against the substrate; a tape hook for limiting movement of an edge of the polishing tape toward the substrate; the tape hook has a tape positioning surface that faces the polishing surface of the edge of the polishing tape; The polishing head, wherein the tape hooks are a plurality of tape hooks arranged on both sides of the pressing mechanism.

4. 4. The polishing head according to claim 3, wherein the plurality of tape hooks each have a plurality of tape positioning surfaces that face the polishing surfaces of both edge portions of the polishing tape.

5. A polishing head for polishing a substrate, comprising: a pressing member that presses the polishing tape against the substrate; a tape hook that limits movement of the edge of the polishing tape toward the substrate; a pressing member holder for holding the pressing member, the tape hook has a tape positioning surface that faces the polishing surface of the edge of the polishing tape; a polishing head, wherein the distance from a reference surface in the pressing member holder to the end surface of the tape hook is shorter than the distance from the reference surface to the tape pressing surface of the pressing member;

6. the tape hook has a protruding portion that protrudes toward the pressing member, 6. The polishing head of claim 5, wherein one side of said protrusion constitutes said tape positioning surface and an opposite side of said protrusion constitutes said end surface of said tape hook.

7. The polishing head of claim 6 , wherein the protrusion is located between the substrate and an edge of the polishing tape.

8. 4. The polishing head according to claim 3, wherein the tape hook and the pressing mechanism are movable together.

9. a substrate holder that holds a substrate; A polishing apparatus for polishing the substrate, comprising the polishing head according to claim 1 .

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