JP5415737B2 - Polishing equipment - Google Patents

Description

  The present invention relates to a polishing apparatus such as a CMP apparatus, and more particularly to a type of polishing apparatus in which a polishing pad is detachably held by a vacuum adsorption action.

  In recent years, as semiconductor integrated circuits are highly integrated and miniaturized, the number of semiconductor manufacturing processes has increased and has become complicated, and along with this, the surface of semiconductor devices has not necessarily become flat. The presence of a step on the surface of a semiconductor device leads to disconnection of the wiring and increase in local resistance, leading to disconnection and a decrease in capacitance. It becomes a factor of.

  On the other hand, with the high integration and miniaturization of semiconductor integrated circuits, the light source wavelength of a semiconductor exposure apparatus used for photolithography is shortened, and the numerical aperture of the projection lens of the semiconductor exposure apparatus, the so-called NA, is increasing. As a result, the depth of focus of the projection lens of the semiconductor exposure apparatus has become substantially shallow, and in order to cope with the decrease in the depth of focus, the surface of the semiconductor device needs to be flattened more than ever. The

  Therefore, as a method for planarizing the surface of a semiconductor device, a chemical mechanical polishing (Chemical Mechanical Polishing or Chemical Mechanical Planarization, hereinafter referred to as CMP) technique is widely used. A polishing pad for polishing a workpiece with a CMP apparatus is worn and clogged as it is used. Therefore, the polishing pad is subjected to surface polishing called dressing and reused. Since the thickness of the polishing pad decreases with the passage of time of use, the polishing pad is replaced when the predetermined thickness is reached (see Patent Document 1).

JP 2005-322876 A

  The polishing pad described in the above-mentioned patent document is configured to be detachably held by a vacuum suction action with respect to the main body side (adapter in the same document) that is rotationally driven. Therefore, the polishing pad improves the workability of replacement. Therefore, a pad material is attached to one side of a thin resin plate that is light and easy to handle with a double-sided adhesive tape. In such a polishing pad, a seal member (O-ring in the same document) for maintaining a degree of vacuum is disposed between the main body side and the plate. This seal member is elastically deformed and crushed when it is vacuum operated and the plate is sucked to the main body, but the pressure generated at that time is transferred to the plate and the pad material, causing a convex portion on the surface of the pad material. There was a problem that uniform polishing could not be performed.

  The present invention has been made in view of the above circumstances, and in a polishing apparatus that detachably holds a polishing pad by vacuum suction, a seal for maintaining a degree of vacuum even if the polishing pad has low rigidity. It is an object of the present invention to provide a polishing apparatus capable of achieving high flatness polishing by performing uniform polishing without transferring a member to a polishing pad.

A polishing apparatus according to the present invention includes a holding unit that holds a workpiece, a polishing wheel that is disposed to face the holding unit, a rotation drive mechanism that rotates the polishing wheel, a holding unit, and a polishing wheel. A polishing apparatus having a feeding means for moving the polishing wheel relative to the rotation axis to press the polishing wheel against a work held by a holding means and polishing the work by the polishing wheel, the polishing wheel holding a polishing pad A mounting member connected to a rotating shaft of the rotation drive mechanism, wherein an air suction port is formed in the holding surface, and an air suction path communicating with the air suction port is formed therein. A polishing pad having a held surface held by the holding surface of the mount member, and forming a space between the holding surface and the held surface, and having flexibility and holding the polishing pad surface In the space between the holding surface of the mount member and surrounding the air suction port, a vacuum region is formed inside itself, and when the air in the vacuum region is sucked, both the held surface and the holding surface and a sealing member annular affected to be brought into close contact with, the seal member is transferred to the polishing pad against to said holding surface from extending obliquely toward a holding surface of the polishing pad And having a flat plate-like seal portion that is in surface contact with the polishing pad without generating a convex portion , and further comprising suction means for sucking air in the vacuum region from the air suction port. It is a feature.

  In the polishing apparatus of the present invention, when the polishing pad is aligned with the holding surface of the mount member and the vacuum operation is performed by the suction means, the air in the vacuum region inside the seal member is sucked through the air suction port, thereby the polishing pad. Is adsorbed and held by the mount member. Further, when the vacuum operation by the suction means is stopped, the polishing pad can be separated from the mount member.

  When the vacuum operation is performed and the polishing pad is adsorbed to the holding surface of the mount member, the seal member is in close contact with both the holding surface of the mount member and the held surface of the polishing pad, and the degree of vacuum in the vacuum region is maintained. Here, the seal portion that is in close contact with the held surface of the polishing pad is formed in a flat plate shape that extends in an oblique direction toward the held surface and then comes into surface contact with the held surface. This shape is a shape in which the seal portion is difficult to adhere to the polishing pad with a strong pressure, and therefore, the transfer of the seal member to the polishing pad is avoided even if the polishing pad has a low rigidity. As a result, uniform polishing by the polishing pad is performed, and high flatness polishing can be achieved.

Hereinafter, more specific features of the present invention will be described. The seal member is fixed to either the holding surface of the mount member or the held surface of the polishing pad. Further, in such a form in which the seal member is fixed to either the holding surface of the mount member or the held surface of the polishing pad, the seal member is held by the holding surface of the mount member or the held surface of the polishing pad. From the adhering part to the surface, it extends in an oblique direction toward the outside of the vacuum region.

  Further, the holding surface of the mount member and / or the held surface of the polishing pad is formed with a guide portion that deforms the seal portion of the seal member so as to extend in the oblique direction. The mount member and the polishing pad are characterized in that a slurry supply path to the polishing surface of the polishing pad is formed in a state where the polishing pad is held by the mount member.

In addition, an air suction path communicating with the air suction path of the mount member is formed on the rotation shaft, and the air suction path on the rotation shaft side is air suction via a rotary joint connected to the rotation shaft. It is characterized by being connected to a source.
In addition, a slurry supply path communicating with the slurry supply path of the mount member is formed on the rotary shaft, and the slurry supply path on the rotary shaft side is supplied with slurry via a rotary joint connected to the rotary shaft. It is characterized by being connected to a source.

  Further, the holding surface of the mount member is formed with a central convex portion at the central portion, an annular outer peripheral convex portion is formed at the outer peripheral portion, and a recess is formed between the central convex portion and the outer peripheral convex portion. A slurry supply passage is opened in the central convex portion, an air suction port is formed in the concave portion, and the polishing pad is held in the mount member while being mounted on the mount pad. A slurry supply path communicating with the slurry supply path of the member is formed, and the seal member includes a first seal member disposed on the inner peripheral side of the air suction port in the recess, and a front of the air suction port. And a second seal member disposed on the outer peripheral side.

  Further, the mounting member and the polishing pad are provided with positioning means for positioning the holding position of the polishing pad with respect to the mount member.

  In addition, although the workpiece | work said by this invention is not specifically limited, For example, the semiconductor wafer which consists of GaAs, silicon, etc., a ceramic, glass, or a sapphire-type board | substrate etc. are mentioned.

  According to the present invention, in the polishing apparatus that holds the polishing pad so as to be detachable by vacuum suction, even if the polishing pad has low rigidity, the seal member for maintaining the degree of vacuum is not transferred to the polishing pad. Thus, uniform polishing is performed, and as a result, polishing with high flatness can be achieved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(1) Polishing Apparatus (1-1) Outline of Polishing Apparatus FIG. 1 shows a CMP apparatus that is a polishing apparatus according to an embodiment. The polishing apparatus 10 performs CMP processing on a disk-shaped semiconductor wafer 1. The wafer 1 is a silicon wafer or the like, which has been previously thinned to a predetermined thickness by grinding, and one or both surfaces are polished flatly to a desired flatness by the polishing apparatus 10.

  The polishing apparatus 10 has a rectangular parallelepiped base 11. A table base 12 is provided on the base 11 so as to be movable in the Y direction, and a disk-shaped chuck table 13 is rotatably supported on the table base 12. The chuck table 13 is of a generally known vacuum chuck type, and the wafer 1 is placed concentrically on the horizontal suction surface 13a of the chuck table 13 and sucked and held.

  The wafer 1 is fed through the table base 12 and the chuck table 13 from the attaching / detaching position at the end in the Y1 direction in FIG. 1 to the processing position at the end in the Y2 direction. The base 11 is provided with a moving mechanism for moving the table base 12 in the Y direction, and the table base 12 is provided with a rotation drive mechanism for rotating the chuck table 13 (all not shown). The base 11 is provided with a bellows-like cover 14 which can block the movement path of the table base 12 and prevent polishing dust and the like from falling into the base 11 so as to extend and contract.

  A polishing unit 20 is disposed above the processing position. The polishing unit 20 is installed on the front surface (Y1 side surface) of the column 15 erected at the end of the base 11 on the Y2 direction side so as to be movable up and down along the Z direction (vertical direction). . That is, a guide 16 extending in the Z direction is provided on the front surface of the column 15, and the polishing unit 20 is slidably mounted on the guide 16 via the slider 17. The polishing unit 20 is moved up and down in the Z direction via a slider 17 by a ball screw type feed mechanism 19 driven by a servo motor 18.

  The polishing unit 20 includes a cylindrical spindle housing 21 whose axial direction extends in the Z direction. The spindle housing 21 is fixed to the front surface of the slider 17. A spindle shaft 23 (see FIG. 4) that is rotationally driven by a spindle motor 22 is coaxially incorporated in the spindle housing 21. The spindle shaft 23 protrudes downward from the lower end of the spindle housing 21, and a disk-like flange 24 is coaxially formed at the protruding end portion. A polishing wheel 29 is detachably attached to the flange 24. Both the axial directions of the spindle shaft 23 and the chuck table 13 are parallel to each other in the Z direction, and the positions of the axes of the spindle shaft 23 and the chuck table 13 in the X direction are the same.

  The polishing wheel 29 includes a mount member 30 that is detachably fixed to the lower surface of the flange 24 by means such as bolting, and a polishing pad 40 that is detachably held on the lower surface of the mount member 30 by a vacuum adsorption action. It is comprised from the sealing members 51 and 52 (refer FIG. 2 and FIG. 3) arrange | positioned between the mount member 30 and the polishing pad 40. FIG. The mount member 30 and the polishing pad 40 are disk-shaped having substantially the same diameter as the flange 24 and are disposed coaxially with the spindle shaft 23. The diameter of the polishing pad 40 is set to be approximately the same as that of the wafer 1 held on the chuck table 13. The grinding wheel 29 will be described in detail later.

  According to the polishing apparatus 10 having the above configuration, the wafer 1 attracted and held by the chuck table 13 at the attachment / detachment position is moved to the processing position below the polishing unit 20 by moving the table base 12 in the Y2 direction. The chuck table 13 is rotated and rotated. Then, while supplying slurry (polishing liquid) to the upper surface of the wafer 1, the flange 24, the mount member 30 and the polishing wheel 29 of the polishing unit 20 are integrally rotated by the spindle motor 22, and the polishing unit 20 is lowered to polish the polishing unit 20. The lower surface of the pad 40 (the lower surface of a pad material 42 described later) is pressed against the upper surface of the wafer 1 with a predetermined load. By this operation, the upper surface of the wafer 1 is subjected to CMP.

The slurry, which is a polishing liquid, is selected according to the type of the wafer 1. For example, an aqueous alkaline chemical solution such as KOH (potassium hydroxide), NaOH (sodium hydroxide), NH ₃ OH (ammonia), A material in which abrasive grains such as ₂ (silicon oxide), Ce (cerium oxide), and Al ₂ O ₃ (alumina) are suspended is used. As an aqueous solution of abrasive grains, an acidic one may be used.

  Further, in the region where the polishing pad 40 is in contact with the wafer 1, the polishing pad 40 that rotates relative to the rotating wafer 1 relatively slides to obtain an effective polishing action, and the entire upper surface of the wafer 1 is covered. The region to be polished. When a predetermined polishing time has elapsed, the polishing unit 20 is raised, the table base 12 is returned to the attachment / detachment position, the rotation of the chuck table 13 is stopped, the polished wafer 1 is picked up, and the polishing process is completed.

(1-2) Polishing Wheel of First Embodiment Next, the polishing wheel 29 will be described.
As shown in FIGS. 2 and 3, a circular central convex portion 32 is formed at the center of the lower surface 31 of the mount member 30, and an annular outer peripheral convex portion 33 is formed at the outer peripheral portion, and these convex portions 32. , 33 is formed with an annular recess 34. The central protrusion 32 and the outer peripheral protrusion 33 have the same amount of protrusion from the bottom surface 34a of the recess 34, and the lower surfaces of these protrusions 32 and 33 are flush.

  A slurry supply path 35 that opens to the lower surface of the central convex portion 32 is formed at the axial center of the mount member 30. The mount member 30 has a plurality of air suction passages 36 formed in parallel with the slurry supply passage 35, and an air suction port 36 a that is an opening of the air suction passage 36 is formed on the bottom surface 34 a of the recess 34. ing. In this case, two air suction passages 36 are formed, and each air suction port 36a is formed at a position 180 degrees apart from each other in the circumferential direction with the central convex portion 32 interposed therebetween.

  As shown in FIG. 4, the spindle shaft 23 is formed with a slurry supply path 25 and an air suction path 26 communicating with the slurry supply path 35 and the air suction path 36 of the mount member 30, respectively. The slurry supply path 25 on the spindle shaft 23 side extends upward from a connection portion with the slurry supply path 35 on the mount member 30 side, and then branches into two left and right sides, and is formed on the outer peripheral surface of the spindle shaft 23. It opens to the groove 25a. Further, the air suction path 26 on the spindle shaft 23 side extends upward from the connection portion with each air suction path 36 on the mount member 30 side, then bends in the direction of the outer peripheral surface, and is formed on the outer peripheral surface of the spindle shaft 23. Open to the circumferential groove 26a.

  As shown in FIG. 4, the spindle shaft 23 is inserted into a cylindrical universal joint 60 supported by the spindle housing 21 so as to be slidable. The universal joint 60 is formed with a slurry introduction path 65 communicating with the circumferential groove 25a and an air suction path 66 communicating with the circumferential groove 26a. A slurry supply source 71 such as a slurry pump is connected to the slurry introduction path 65 via a pipe 71A, and an air suction source 72 such as a compressor is connected to the air suction path 66 via a pipe 72A. .

  When the slurry supply source 71 operates, the slurry is introduced from the pipe 71A into the slurry introduction path 65 of the universal joint 60, and then enters the circumferential groove 25a of the spindle shaft 23, passes through the slurry supply path 25, and passes through the slurry supply path of the mount member 30. 35. When the air suction source 72 is activated, the air from the air suction port 36a of the mount member 30 passes through the air suction path 36 of the mount member 30, the air suction path 26 of the spindle shaft 23, and the circumferential groove 26a, and then the universal joint 60. The air suction path 66 is sucked into the air suction source 72 through the pipe 72A.

  Although the spindle shaft 23 is rotated by the spindle motor 22, the circumferential grooves 25a and 26a always communicate with the slurry introduction path 65 and the air suction path 66 on the universal joint 60 side even when the spindle shaft 23 rotates. Supply and air suction are performed stably without any delay. An O-ring 61 is provided around the connection portion of each flow path to keep the airtight state and suppress leakage of slurry and air.

  The polishing pad 40 is made of a resin such as PET (polyethylene terephthalate), and a disk-shaped pad material 42 having the same diameter as the plate 41 is provided on one surface of a disk-shaped plate 41 having a flat surface and a constant thickness. Constructed by concentrically pasting. The pad material 42 is selected according to the wafer 1 that is the object to be polished. For example, polyurethane formed by foaming or forming a fibrous material into a sheet shape is used. The pad material 42 is affixed to the plate 41 with, for example, a double-sided adhesive tape, and is peeled off from the plate 41 and replaced with a new pad material 42 at the time of replacement. At the center of the polishing pad 40, a slurry supply port 40a is formed.

  The polishing pad 40 is adsorbed and held on the mount member 30 by a vacuum adsorption action in a state where the plate 41 is aligned with the lower surfaces of the central convex portion 32 and the outer peripheral convex portion 33 of the lower surface 31 of the mount member 30. At that time, a space 45 is formed between the bottom surface 34 a of the recess 34 of the mount member 30 and the top surface 41 a of the plate 41, and the slurry supply port 40 a of the polishing pad 40 communicates with the slurry supply path 35 of the mount member 30. To do. In the recess 34 of the mount member 30, two seal members 51 and 52 for generating a vacuum adsorption action and maintaining the degree of vacuum are fixed.

  Each of the sealing members 51 and 52 is made of a material having elasticity such as rubber, and both of them are made of a flat plate material having a constant thickness in an annular shape and inclined in an oblique direction with respect to its own axial direction from the inner peripheral edge to the outer peripheral edge. It is molded into a skirt shape. These seal members 51 and 52 have the same thickness and width (dimensions extending from the inner periphery to the outer periphery), but have different diameters. The first seal member 51 is on the smaller diameter side, and the second seal member is on the larger diameter side. 52.

  The first seal member 51 is disposed inside the two air suction ports 36a, concentrically with the recess 34, and narrows toward the lower side (the polishing pad 40 side). A plurality of portions, that is, a plurality of peripheral edge portions are fixed to the bottom surface 34 a of the recess 34 with screws 49. On the other hand, the second seal member 52 is disposed on the outer peripheral side of the air suction port 36a concentrically with the recess 34 and in a state of expanding toward the lower side. A plurality of locations on the side edge are fixed to the bottom surface 34 a of the recess 34 by screws 49. Therefore, the two air suction ports 36 a of the mount member 30 are surrounded by the first seal member 51 and the second seal member 52.

  Thus, in the state attached to the mount member 30, the upper end part which is the fixing part by the screw | thread 49 of each sealing member 51 and 52 is closely_contact | adhered to the bottom face 34a of the recess 34, and is horizontal. The lower portion from the upper end extends in an oblique direction away from the air suction port 36a as it goes downward, and the lower end protrudes from the recess 34 by a predetermined length. In this case, the portions extending in the oblique direction of the seal members 51 and 52 are the seal portions 51a and 52a, respectively.

  In the polishing wheel 29, during the operation in which the polishing apparatus 10 polishes the wafer 1 as described above, the polishing pad 40 is adsorbed and held on the mount member 30 by a vacuum adsorption action as shown in FIG. In this state, the slurry supply port 40a of the polishing pad 40 communicates with the slurry supply path 35 of the mount member 30, and the slurry supplied to the slurry supply path 35 during the polishing operation is downward from the slurry supply port 40a of the polishing pad 40. It flows out and is supplied to the upper surface 41 a of the wafer 1. The slurry supply port 40a faces the upper surface of the wafer 1 at the time of wafer polishing, and is positioned at a position where the slurry is sufficiently supplied to the upper surface of the wafer 1.

  In order for the polishing pad 40 to be attracted and held by the mount member 30, the upper surface 41 a of the plate 41 is concentrically aligned with the lower surface 31 of the mount member 30 with the plate 41 of the polishing pad 40 facing upward. When the plate 41 is aligned with the mount member 30, the seal portions 51 a and 52 a of the first seal member 51 and the second seal member 52 are pressed and bent by the plate 41 and come into surface contact with the upper surface 41 a of the plate 41. As a result, an annular vacuum region 45 a surrounded by the first seal member 51 and the second seal member 52 is formed in the space 45.

  Next, the air suction source 72 is activated. Then, air in the vacuum region 45a is sucked from the air suction port 36a, and the upper surface 41a of the plate 41 of the polishing pad 40 is brought into close contact with the lower surfaces of the central convex portion 32 and the outer peripheral convex portion 33 of the mount member 30, and the polishing pad 40 is mounted. Adsorbed and held on the member 30. When the polishing pad 40 is attracted and held by the mount member 30, the upper ends of the first seal member 51 and the second seal member 52 are in close contact with the bottom surface 34 a of the recess 34 of the mount member 30, and the lower ends The portion is in close contact with the upper surface 41 a of the plate 41.

  The seal portions 51a and 52a of the seal members 51 and 52 that are in close contact with the upper surface 41a of the plate 41 extend in an oblique direction toward the upper surface 41a of the plate 41 and then come into surface contact with the upper surface 41a. These sealing portions 51a and 52a are flat plates that are easily elastically deformed in the first place. In addition, the sealing portions 51a and 52a extend in an oblique direction with respect to the upper surface 41a of the plate 41. It will not be in a state to do. Therefore, even if the plate 41 is thin and has a low rigidity, the phenomenon that the seal members 51 and 52 are transferred to the polishing pad 40 does not occur, and the polishing surface of the pad material 42 is kept flat. As a result, uniform polishing can be performed and high flatness polishing can be achieved.

  Further, each of the seal members 51 and 52 extends in an oblique direction from the portion fixed to the mount member 30 toward the outside of the vacuum region 45a. Here, the outer side means that the inner seal member 51 is on the central convex portion 32 side, and the outer seal member 52 is on the outer peripheral convex portion 32 side. As described above, since the seal members 51 and 52 extend obliquely from the portion fixed to the mount member 30 toward the outside of the vacuum region 45a, the air in the vacuum region 45a is sucked from the air suction port 36a. Then, the lower end, which is the free side edge that is not fixed, securely contacts and adheres to the upper surface 41a of the plate 41 of the polishing pad 40.

  The adhesion of the free side edge to the plate 41 is caused by the fact that it extends obliquely from the portion fixed to the mount member 30 toward the outside of the vacuum region 45a, and the degree of vacuum of the vacuum region 45a. The higher the value, the stronger the adhesion and the higher the sealing performance.

  Hereinafter, other embodiments of the grinding wheel concerning the present invention are described. In the drawings referred to in these embodiments, the same components as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.

(2) Polishing Wheel and Seal Member of Second Embodiment FIG. 5 shows a polishing wheel 29 of the second embodiment of the present invention. In this case, an annular recess 37 that is one step deeper is formed concentrically in the center of the recess 34 in the recess 34 of the lower surface 31 of the mount member 30, and the air suction port 36 a The bottom surface 37a of the recess 37 is open. An annular first seal member 51 is fixed to the inner peripheral wall 37b of the recess 37 on the small diameter side by screws 49, and an annular second seal member 52 is fixed to the outer peripheral wall 37c by screws 49. .

  The first seal member 51 in this case has a shape that narrows while curving as it goes downward from the adhering portion to the inner peripheral wall 37b along the vertical direction. On the other hand, the 2nd seal member 52 is formed in the shape which spreads while curving as it goes below from the adhering part to peripheral wall 37c along the up-and-down direction. In both of the seal members 51 and 52, the curved portions below the fixing portion to the mount member 30 are the seal portions 51a and 52a.

  In the second embodiment, as shown in FIG. 5B, when the polishing pad 40 is attracted and held by the mount member 30, the seal portions 51a and 52a of the seal members 51 and 52 bend following the curved state. The plate 41 is in close contact with the upper surface 41a. The seal portions 51a and 52a of this embodiment are in contact with the upper surface 41a of the plate 41 while being curved from above, but the portion immediately before the contact is in an obliquely extending state. For this reason, the pressing force to the plate 41 is not strong as in the above embodiment, and is not transferred to the polishing pad 40.

(3) Polishing wheel of 3rd Embodiment FIG. 6: has shown the grinding wheel 29 of 3rd Embodiment of this invention. In this embodiment as well, another annular deep recess 38 is formed concentrically in the center of the recess 34 in the recess 34 on the lower surface 31 of the mount member 30, and air suction is applied to the bottom surface 38 a of the recess 38. The mouth 36a is open. In this case, the inner peripheral wall 38b and the outer peripheral wall 38c that form the recess 38 on the small diameter side are formed on inclined surfaces that expand downward. The first seal member 51 and the second seal member 52 are fixed to the inner peripheral wall 38b and the outer peripheral wall 38c by screws 49, respectively.

  As shown in FIG. 7, these seal members 51 and 52 are ring-shaped members formed in a flat state that is not three-dimensional in a free state. The small-diameter first seal member 51 is fixed to the inner peripheral portion of the bottom surface 38a of the recess 38 on the small-diameter side by an edge on the outer peripheral side and fixed by screws 49. As a result, the inner peripheral wall 38b is inclined with respect to the inner peripheral portion with respect to the fixing portion, and is deformed into a tapered shape that narrows downward. In the first seal member 51, a portion extending downward and narrowing downward from the inner peripheral wall 38b serves as a seal portion 51a.

  On the other hand, the large-diameter second seal member 52 has an inner peripheral edge closely attached to an outer peripheral portion of the bottom surface 38a of the small-diameter recess 38 and is fixed by a screw 49. Thereby, the part of the outer peripheral side rather than the adhering part is brought into contact with the inclined outer peripheral wall 38c, and is deformed into a skirt shape that expands downward. In the second seal member 52, a portion extending downward and extending downward from the outer peripheral wall 38c serves as a seal portion 52a.

  The seal members 51 and 52 deformed by contact with the inner peripheral wall 38b and the outer peripheral wall 38c in this manner are in contact with the upper surface 41a of the plate 41 of the polishing pad 40 in an oblique direction as in the first embodiment. As a result, the same operation and effect can be obtained that the transfer to the polishing pad 40 is not performed.

  Further, in the third embodiment, as shown in FIG. 8, a plurality of protrusions 38 d that protrude downward are formed at equal intervals in the circumferential direction on the lower surface of the outer peripheral convex portion 33 of the mount member 30. A hole 41d that engages with the protrusion 38d is formed in the upper surface 41a of the plate 41 of the mating polishing pad 40. According to this configuration, the concentric positioning of the polishing pad 40 with respect to the mount member 30 can be smoothly and reliably performed by engaging the hole 41d of the polishing pad 40 with the protrusion 38d of the mount member 30. The effect that it is possible is produced.

(4) Polishing Wheel of Fourth Embodiment In each of the above embodiments, the seal members 51 and 52 are attached to the mount member 30, but the present invention includes a configuration in which the seal member is attached to the polishing pad 40 side. FIG. 9 shows an example in which the first seal member 51 and the second seal member 52 are attached to the polishing pad 40 side in the mount member 30 and the polishing pad 40 shown in FIG.

  The orientation of the seal members 51 and 52 in this embodiment is opposite to that of the first embodiment, and the first seal member 51 is such that the outer peripheral edge is fixed to the upper surface 41a of the plate 41 and becomes narrower as it goes upward. It is arranged. On the other hand, the second seal member 52 is disposed in such a manner that its inner peripheral end is fixed to the upper surface 41a of the plate 41 and expands upward. In other words, the seal members 51 and 52 are disposed on the outer side of the vacuum region 45a from the portion where the polishing pad 40 is fixed to the plate 41 (on the slurry supply port 40a side in the inner seal member 51, on the outer seal member 52). It extends in an oblique direction toward the outer peripheral edge. With this arrangement, when the polishing pad 40 is vacuum-sucked as shown in FIG. 9B, the upper edge of the seal members 51 and 52 that are not fixed is the recess of the mount member 30. It adheres to the bottom surface 34a of 34, and a vacuum degree is maintained.

  In this case, as a means for fixing the seal members 51 and 52 to the plate 41, screw fixing is inappropriate considering that the plate 41 is thin and has low rigidity. A method of fixing by using an adhesive tape or the like is appropriate.

(5) Polishing Wheel of Fifth Embodiment In the above embodiment, a plurality (two) of air suction ports 36a are collectively surrounded by two seal portions 51, 52 on the inner peripheral side and the outer peripheral side. However, the structure which surrounds one air suction opening 36a with one seal member may be sufficient.

  FIG. 10 and FIG. 11 show such an example. On the lower surface 31 of the mount member 30, circular recesses 39 are formed concentrically around each air suction port 36a. A skirt-like seal member 53 surrounding the air suction port 36 a is concentrically disposed and fixed to the bottom surface 39 a of each recess 39. As shown in FIG. 10, each sealing member 53 has an inner peripheral edge fixed to the bottom surface 39 a of the recess 34 by a screw 49 and arranged so as to expand downward, and during vacuum suction, The seal portion 53 a extends obliquely to the upper surface 41 a of the plate 41 of the polishing pad 40 and is in close contact with the upper surface 41 a, and a vacuum region 45 a is formed inside one seal member 53.

  In the seal member 53 in this embodiment, it extends in an oblique direction from the portion fixed to the mount member 30 to the outside of the vacuum region 45a (the outside here is the outer peripheral side of the vacuum region 45a). The lower end, which is the edge, is effectively brought into close contact with the plate 41 of the polishing pad 40, and the degree of vacuum is maintained.

1 is a perspective view of a polishing apparatus according to an embodiment of the present invention. It is a disassembled perspective view which shows the lower surface side of the grinding | polishing wheel which concerns on 1st Embodiment of this invention. It is sectional drawing of the polishing wheel which concerns on 1st Embodiment, Comprising: (a) is before polishing pad adsorption | suction, (b) has shown after polishing pad adsorption | suction. It is sectional drawing which shows the slurry supply structure and air suction structure to the grinding | polishing wheel which concern on 1st Embodiment. It is sectional drawing of the polishing wheel which concerns on 2nd Embodiment, Comprising: (a) is before polishing pad adsorption | suction, (b) has shown after polishing pad adsorption | suction. It is sectional drawing of the polishing wheel which concerns on 3rd Embodiment, (a) is before polishing pad adsorption | suction, (b) has shown after polishing pad adsorption | suction. It is (a) perspective view of the sealing member which concerns on 3rd Embodiment, (b) It is sectional drawing. It is an enlarged view of the part shown by VIII of FIG. It is sectional drawing of the grinding | polishing wheel which concerns on 4th Embodiment, (a) is before polishing pad adsorption | suction, (b) has shown after polishing pad adsorption | suction. It is sectional drawing of the grinding | polishing wheel which concerns on 5th Embodiment, (a) is before polishing pad adsorption | suction, (b) has shown after polishing pad adsorption | suction. It is a bottom view of the mounting member and seal member of the grinding wheel concerning a 5th embodiment.

Explanation of symbols

1 ... wafer (work)
DESCRIPTION OF SYMBOLS 10 ... Polishing apparatus 13 ... Chuck table (holding means)
DESCRIPTION OF SYMBOLS 19 ... Feed mechanism 20 ... Polishing unit 22 ... Spindle motor (rotation drive mechanism)
23 ... Spindle shaft (rotary drive mechanism, rotating shaft)
25 ... Slurry supply path of spindle shaft 26 ... Air suction path of spindle shaft 29 ... Polishing wheel 30 ... Mount member 31 ... Lower surface (holding surface)
32 ... Central convex part 33 ... Outer peripheral convex part 34 ... Recess 35 ... Slurry supply path of mount member 36 ... Air suction path of mount member 36a ... Air suction port 38b ... Inner peripheral wall (guide part)
38c ... Outer wall (guide part)
38d ... projection (positioning means)
40 ... Polishing pad 40a ... Slurry supply port (slurry pad slurry supply passage)
41a: Plate upper surface (held surface)
41d ... hole (positioning means)
DESCRIPTION OF SYMBOLS 42 ... Pad material 45 ... Space 45a ... Vacuum area 51 ... 1st sealing member 52 ... 2nd sealing member 53 ... Sealing member 51a, 52a, 53a ... Sealing part 60 ... Rotary joint 71 ... Slurry supply source 72 ... Air suction source

Claims (9)

Holding means for holding the workpiece;
A polishing wheel disposed opposite the holding means;
A rotation drive mechanism for rotating the grinding wheel;
A feeding means for causing the holding means and the grinding wheel to move relative to each other in the rotational axis direction of the grinding wheel to press the grinding wheel against the work held by the holding means, and to polish the work by the grinding wheel; A polishing apparatus comprising:
The polishing wheel is
It has a holding surface for holding the polishing pad, an air suction port is formed on the holding surface, an air suction path communicating with the air suction port is formed inside, and it is connected to the rotating shaft of the rotation drive mechanism A mounting member to be
A polishing pad having a held surface held by the holding surface of the mount member, and forming a space between the holding surface and the held surface;
Having flexibility, forming a vacuum region inside itself surrounding the air suction port in the space between the held surface of the polishing pad and the holding surface of the mount member; An annular seal member that receives an action of being brought into close contact with both the held surface and the holding surface when air in a vacuum region is sucked;
The seal member, the state projections on the polishing pad by the extend obliquely towards the held surface is transferred to the polishing pad against to said holding surface not to occur in the polishing pad It has a flat seal part that makes surface contact with
The polishing apparatus further includes an air suction source for sucking air in the vacuum region from the air suction port.   The polishing apparatus according to claim 1, wherein the seal member is fixed to either the holding surface of the mount member or the held surface of the polishing pad.   2. The seal member according to claim 1, wherein the seal member extends in an oblique direction toward the outside of the vacuum region from a holding portion of the mount member or a fixing portion of the polishing pad to the held surface. Or the polishing apparatus according to 2;   The holding surface of the mount member and / or the held surface of the polishing pad is formed with a guide portion that deforms the seal portion of the seal member so as to extend in the oblique direction. The polishing apparatus according to claim 1.   5. The slurry supply path to the polishing surface of the polishing pad is formed in the mount member and the polishing pad in a state where the polishing pad is held by the mount member. The polishing apparatus according to any one of the above.   An air suction path communicating with the air suction path of the mount member is formed on the rotation shaft, and the air suction path on the rotation shaft side is connected to the air via a rotary joint connected to the rotation shaft. The polishing apparatus according to claim 1, wherein the polishing apparatus is communicated with a suction source. A slurry supply path communicating with the slurry supply path of the mount member is formed on the rotary shaft, and the slurry supply path on the rotary shaft side is supplied with slurry via a rotary joint connected to the rotary shaft. The polishing apparatus according to claim 5, wherein the polishing apparatus is communicated with a source. On the holding surface of the mount member, a central convex portion is formed at the central portion, an annular outer peripheral convex portion is formed at the outer peripheral portion, and a recess is formed between the central convex portion and the outer peripheral convex portion. The slurry supply path is open in the central convex portion, and the air suction port is formed in the recess,
The polishing pad is formed with a slurry supply path communicating with the slurry supply path of the mount member while being held by the mount member.
The seal member includes a first seal member disposed on an inner peripheral side of the air suction port and a second seal member disposed on an outer peripheral side of the air suction port in the recess. The polishing apparatus according to claim 1, wherein the polishing apparatus is provided.   The polishing apparatus according to claim 1, wherein positioning means for positioning a holding position of the polishing pad with respect to the mount member is provided on the mount member and the polishing pad.

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