JP6298681B2 - Polishing apparatus and polishing pad dressing method - Google Patents

Description

The present invention is a polishing apparatus for polishing a wafer while supplying a slurry, a polishing surface of the polishing pad relating to dress method to that Migaku Ken pad dress the polishing apparatus.

  In a polishing apparatus for polishing a plate-like workpiece such as a wafer, the plate-like workpiece is held on a chuck table, and slurry is entered between the plate-like workpiece and a polishing pad to polish the plate-like workpiece (for example, Patent Document 1). In such a polishing apparatus, when the polishing surface of the polishing pad is clogged with reaction products or processing waste generated by polishing, the slurry cannot enter between the plate-like workpiece and the polishing pad, resulting in the plate-like workpiece being There is a problem that polishing becomes impossible. For this reason, a new slurry is fixed to the polishing pad by periodically dressing the polishing surface of the polishing pad.

  Conventionally, as a method for dressing a polishing surface of a polishing pad, a method of fixing a slurry on a polishing surface while dressing the polishing surface of the polishing pad is known (see Patent Document 2). In the dressing method described in Patent Document 2, slurry is caused to enter between the polishing surface of the polishing pad and the dress surface of the dressing mechanism, and the polishing surface of the polishing pad is dressed under supply of the slurry. As a result, the slurry fixed on the polishing surface is not washed away during the dressing of the polishing surface of the polishing pad, and the dressing is performed while fixing a new slurry on the polishing surface, so that the polishing performance is not deteriorated immediately after the dressing. The plate workpiece is polished.

Japanese National Patent Publication No. 11-505181 JP 2013-215895 A

  However, in the dressing method described in Patent Document 2, the polishing surface of the polishing pad and the dressing surface of the dressing mechanism are not necessarily parallel, and in this state, a portion that has been dressed on the polishing surface and a portion that is not dressed are created. It will be. More specifically, a concentric striped pattern is formed by a portion that is not a portion dressed by a small-diameter dress surface with respect to a polishing surface obtained by rotating the polishing pad. This stripe pattern makes it difficult for the slurry to enter and discharge between the polishing pad and the plate-like workpiece, making it impossible to fix new slurry on the polishing surface of the polishing pad.

The present invention has been made in view of the foregoing, without creating uneven polishing surface of the polishing pad, evenly Migaku Ken Ru can dress apparatus a polishing surface, to provide a dress method for a polishing pad For the purpose.

The polishing apparatus of the present invention includes a dressing mechanism for dressing a polishing pad having a polishing surface for polishing a plate-like workpiece, a chuck table having a holding surface for holding the plate-like workpiece, and a plate-like workpiece held by the chuck table. A polishing means for rotatably mounting the polishing pad for polishing, a polishing feed means for approaching and separating the polishing means from the chuck table, the polishing means and the chuck table, or the polishing means and the dressing mechanism And a radial direction moving means for relatively moving in the radial direction of the polishing pad, the polishing means comprising a disk-shaped platen having a mounting surface for mounting the polishing pad; and a spindle for rotating said platen, said dress mechanism includes a disc-shaped dress plate having a dress surface in contact with the polishing surface, to the dress plate Binding to a rotating shaft for rotating the center of the dress plate axis, an adjustment unit for adjusting the inclination perpendicular to the said rotary shaft and said mounting surface of said platen in said dress plate, the rotary shaft and the dress plate And a tilt varying mechanism that tilts the dress surface in accordance with the tilt of the polishing surface, the tilt varying mechanism having a fulcrum on the center axis of the dress plate and the rotation A spherical seat whose shaft supports the dress plate, an anti-rattle portion for preventing the dress plate from rattling when the dress plate supported by the spherical seat is tilt-variable by pressing of the polishing pad, and the polishing pad A limiting portion that limits the inclination of the dress plate that is variable in inclination by pressing, and the polishing surface in the dress and the dress surface are parallel to each other.

  According to this configuration, since the dress plate is supported on the spherical seat so as to be tiltable about the rotation axis, when the dress surface of the dress plate comes into contact with the polishing surface of the polishing pad, it follows the surface shape of the polishing surface. The inclination of the dress surface is variable. At this time, since the backlash when the dress plate is tilted is prevented, the dress surface can smoothly follow the surface shape of the polishing surface. Since the polishing surface of the polishing pad and the dress surface of the dress plate are abutted in parallel, the entire dress surface can be uniformly applied to the polishing surface, and the polishing pad can be dressed evenly. Accordingly, the slurry enters and discharges between the polishing pad and the plate workpiece, and the new slurry is fixed on the polishing surface of the polishing pad, so that the plate workpiece is polished well.

  In the polishing apparatus of the present invention, the polishing means or the dressing mechanism is provided with a pressure detection unit that presses the polishing pad, and the pressure of the polishing pad detected by the pressure detection unit is monitored and applied to the polishing surface. A polishing feed control unit that controls the polishing feed means so that the pressure value detected by the pressure detection unit does not exceed a preset pressure setting value during the dress contacting the dress surface is provided.

  In the polishing apparatus of the present invention, a dress plate rotation control unit that controls the rotation speed of the dress plate, a polishing pad rotation control unit that controls the rotation speed of the polishing pad, and the positional relationship between the polishing pad and the dress plate A positional relationship recognizing unit for recognizing, and based on the positional relationship recognized by the positional relationship recognizing unit, the circumferential speed difference between the dress plate and the polishing pad becomes uniform in the radial direction of the polishing pad. As described above, the rotation speeds of the dress plate and the polishing pad are controlled by the dress plate rotation control unit and the polishing pad rotation control unit.

  A polishing pad dressing method using the polishing apparatus of the present invention, wherein the polishing pad and the dress plate are rotated in the same direction, and the center of the dress surface and the polishing are rotated using the radial movement means. A starting step of aligning the center of the surface and bringing the dressing surface into contact with the polishing surface; and after the starting step, the radial movement means is used to move the dress plate toward the outside of the polishing pad. When the center of the dress plate comes to the outer periphery of the polishing surface, the polishing pad and the dress surface are moved away from each other in a direction to end polishing, and the start step and the end step are designated. And repeating the process a number of times.

  According to the present invention, the dress surface of the dressing plate is tilted in accordance with the surface shape of the polishing surface of the polishing pad, so that the dressing surface of the polishing pad can be uniformly dressed without unevenness.

It is a mimetic diagram of a polish device concerning this embodiment. It is a detailed block diagram of the inclination variable mechanism which concerns on this Embodiment. It is explanatory drawing of the dressing method of the polishing pad which concerns on this Embodiment.

  Hereinafter, a polishing apparatus according to the present embodiment will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a polishing apparatus according to the present embodiment. Note that the polishing apparatus according to the present embodiment is not limited to the apparatus configuration dedicated to polishing as shown in FIG. 1, and a series of processes such as grinding, polishing, and cleaning are performed fully automatically. It may be incorporated into a fully automatic type processing apparatus.

  As shown in FIG. 1, the polishing apparatus 1 causes a slurry to enter between the plate-like workpiece W on the chuck table 11 and the polishing pad 36, and forms the plate-like workpiece W by chemical mechanical polishing (CMP). It is configured to polish. Further, the polishing apparatus 1 is configured to periodically dress the polishing surface 37 of the polishing pad 36 by the dress mechanism 12 so as to remove processing waste and reaction products during polishing. In the polishing apparatus 1, clogging of the polishing surface 37 of the polishing pad 36 is suppressed by regular dressing by the dress mechanism 12, and the plate-like workpiece W is polished well.

As the plate-like workpiece W, a semiconductor substrate such as a silicon wafer (Si), gallium arsenide (GaAs), or silicon carbide (SiC), ceramic, glass, a sapphire (Al ₂ O ₃ ) based inorganic material substrate, a plate metal Alternatively, a ductile substrate made of resin, or various processed substrates that require flatness (TTV: Total Thickness Variation) from the micron order to the submicron order may be used. Here, the flatness means a difference between the maximum value and the minimum value among the heights measured in the thickness direction with the surface to be polished of the plate-like workpiece W as a reference surface.

  The chuck table 11 of the polishing apparatus 1 is formed in a circular shape when viewed from above, and is rotatably provided on a base (not shown). A holding surface 29 is formed of a porous ceramic material on the upper surface of the chuck table 11. The holding surface 29 is connected to a suction source (not shown), and the plate-like workpiece W is sucked and held by the negative pressure generated on the holding surface 29. Note that the holding surface 29 of the chuck table 11 may be formed completely flat, or formed in a conical shape with a gentle inclination with the rotation axis as the apex as used in a full-auto type grinding apparatus. May be.

  Above the dressing mechanism 12 in FIG. 1, polishing means 13 for polishing the plate-like workpiece W held on the chuck table 11 is provided. In the polishing means 13, a disk-like platen 32 is provided at the lower end of the spindle 31, and a polishing pad 36 is attached to a mounting surface (lower surface) 33 of the platen 32 via an adhesive layer 34. The polishing pad 36 is formed in a circular sheet shape using, for example, foamed urethane or nonwoven fabric. Further, the polishing means 13 is moved in the vertical direction approaching and separating from the chuck table 11 by the polishing feed means 14, and is moved in the radial direction of the polishing pad 36 by the radial direction moving means 15.

  At the time of polishing, the slurry is supplied between the plate-like workpiece W on the chuck table 11 and the polishing pad 36 by the slurry supply unit (not shown) of the polishing unit 13. Then, the platen 32 is rotated by the spindle 31 and the polishing pad 36 is brought into rotational contact with the plate-like workpiece W, whereby the plate-like workpiece W and the polishing pad 36 are relatively slid to polish the plate-like workpiece W. Is done. Examples of the slurry used in the polishing process include a polishing agent using crocoidal silica as a base abrasive, a polishing agent using alumina fine abrasive as a base abrasive, and a polishing agent using cerium oxide as a base abrasive. used.

  Incidentally, the polishing pad 36 of the polishing means 13 is periodically dressed, but the polishing surface 37 of the polishing pad 36 is not necessarily formed flat. For this reason, when the polishing surface 37 is dressed without considering the uneven shape of the polishing surface 37 of the polishing pad 36, a concentric striped pattern is formed on the polishing surface 37 by the dressed portion and the undressed portion. When the plate-like workpiece W is polished with the polishing pad 36, the slurry does not spread over the entire polishing pad 36, and the slurry cannot be fixed to the entire polishing surface 37 and polished.

  For this reason, in the polishing apparatus 1 according to the present embodiment, the dress surface 49 of the dress mechanism 12 can be tilted, and polishing is performed while following the surface shape of the polishing surface 37 of the polishing pad 36. The dress mechanism 12 is provided with a disk-shaped dress plate 41 having a dress surface 49 that contacts the polishing surface 37. The dress plate 41 is formed by electrodepositing diamond abrasive grains on the dress surface 49 of the plate, and is fixed to the upper surface of the base plate 42 having the skirt portion 56. The base plate 42 is supported by an upper end portion of the rotating shaft 43 accommodated in the housing 47 so as to be tiltable via a tilt varying mechanism 44. The details of the tilt varying mechanism 44 will be described later.

  The rotating shaft 43 is connected to a dress rotating unit 45 such as a motor, and the dress plate 41 is rotated about the vertical axis via the rotating shaft 43. Further, an adjustment portion 46 that adjusts the inclination of the rotation shaft 43 is provided at the lower end portion of the dressing mechanism 12 in a direction orthogonal to the mounting surface 33 of the platen 32 of the polishing means 13. For example, the adjusting unit 46 supports the dress mechanism at three points by two movable shafts and one fixed shaft, and tilts the rotary shaft 43 by moving the movable shaft up and down relative to the fixed shaft. The inclination of the dressing mechanism 12 with respect to the platen 32 is adjusted by the adjusting unit 46, and the inclination of the dressing plate 41 with respect to the polishing surface 37 of the polishing pad 36 is varied by the inclination varying mechanism 44.

  Further, the polishing apparatus 1 is provided with a control means 16 that performs overall control of each part of the apparatus. The control unit 16 includes a processor that executes various processes, a memory, and the like. The memory is composed of one or a plurality of storage media such as a ROM (Read Only Memory) and a RAM (Random Access Memory) depending on the application. The control unit 16 includes a polishing feed control unit 21 that controls the polishing feed unit 14, a polishing pad rotation control unit 22 that varies the rotation speed of the polishing pad 36, and a dress plate rotation control unit 23 that varies the rotation speed of the dress plate 41. A positional relationship recognition unit 27 is provided for recognizing the relative positional relationship between the dress plate 41 and the polishing pad 36 according to the output of the radial direction moving means 15.

  The polishing feed control unit 21 is connected to a pressure detection unit 24 provided in the polishing unit 13, and controls the polishing feed amount according to the pressure of the polishing pad 36 detected by the pressure detection unit 24. In this case, the polishing feed control unit 21 monitors the pressure of the polishing pad 36 output from the pressure detection unit 24, and the polishing feed so that the pressure value during dressing of the polishing pad 36 does not exceed a preset pressure setting value. The means 14 is controlled. As a result, the dress plate 41 does not hit the polishing surface 37 of the polishing pad 36 excessively, and the polishing pad 36 can be dressed by the dress mechanism 12 within the set pressure range.

  The polishing pad rotation control unit 22 is connected to a polishing pad rotation variable unit 25 connected to the polishing means 13, and the polishing pad rotation variable unit 25 changes the rotation speed of the polishing pad 36. The polishing pad rotation control unit 22 receives a radial contact position (positional relationship) between the dress plate 41 and the polishing pad 36 from the positional relationship recognition unit 27, and corresponds to the positional relationship recognized by the positional relationship recognition unit 27. The rotational speed of the polishing pad 36 is varied. In this case, the rotational speed of the polishing pad 36 is changed to a low speed as the contact position moves radially outward from the vicinity of the center of the polishing pad 36. As a result, the polishing pad 36 and the dress plate 41 are rotationally contacted at a substantially uniform relative speed near the center of the polishing pad 36 where the circumferential speed is small and near the periphery where the circumferential speed is large.

  The dress plate rotation control unit 23 is connected to a dress rotation variable unit 26 connected to the dress mechanism 12, and the dress rotation variable unit 26 varies the rotation speed of the dress plate 41. The dress plate rotation control unit 23 receives a radial contact position (positional relationship) between the dressplate 41 and the polishing pad 36 from the positional relationship recognition unit 27, and corresponds to the positional relationship recognized by the positional relationship recognition unit 27. The rotational speed of the dress plate 41 is varied. In this case, the rotational speed of the dress plate 41 is varied at a higher speed as the radial contact position moves from the vicinity of the center of the polishing pad 36 toward the radially outer side. Thus, the polishing pad 36 and the dress plate 41 are rotationally contacted at a uniform relative speed near the center of the polishing pad 36 where the circumferential speed is small and near the outer periphery where the circumferential speed is large.

  Here, with reference to FIG. 2, the detailed configuration of the tilt variable mechanism will be described. FIG. 2 is a detailed configuration diagram of the variable tilt mechanism according to the present embodiment. 2A shows a state where the polishing pad is not dressed, and FIG. 2B shows a state where the polishing pad is dressed.

  As shown in FIG. 2A, the rotating shaft 43 of the dress mechanism 12 is connected to the dress plate 41 (base plate 42) via the tilt varying mechanism 44, and the housing 47 is rotated so as to rotate around the center of the dress plate 41. Is housed inside. An upper portion of the rotation shaft 43 is a flange-shaped support portion 51 that supports the dress plate 41 so as to be tiltable. A spherical seat 52 serving as a fulcrum when the dress plate 41 is tilted with respect to the rotation shaft 43 is formed on the central axis of the upper surface of the support portion 51. A large-diameter O-ring 53 interposed between the base plate 42 and the support portion 51 is installed around the spherical seat 52.

  The base plate 42 includes a flat portion 55 to which the dress plate 41 is attached and a skirt portion 56 provided around the flat portion 55. A spherical portion 57 supported by the spherical seat 52 of the rotating shaft 43 is provided at the center of the lower surface of the flat portion 55. Since the spherical surface portion 57 of the base plate 42 is placed on the spherical seat 52 of the rotating shaft 43, the base plate 42 is tiltably supported with respect to the rotating shaft 43. An annular recess 58 is formed in the flat portion 55 around the central axis of the dress plate 41. A plurality of collars 61 projecting from the upper surface of the support portion 51 of the rotating shaft 43 are projected through the plurality of openings at the bottom of the annular recess 58 inside the annular recess 58.

  The base plate 42 is connected to the rotary shaft 43 by inserting a connecting bolt 63 into the collar 61 via a washer 62. The fastening amount of the connecting bolt 63 is regulated so that a gap is left between the base plate 42 and the support portion 51 by the protruding amount of the collar 61 and the thickness of the washer 62. A small-diameter O-ring 54 interposed between the bottom of the annular recess 58 and the washer 62 is installed around each connecting bolt 63. As described above, the gap between the base plate 42 and the support portion 51 is filled with the large-diameter O-ring 53, and the gap between the washer 62 and the bottom of the annular recess 58 is filled with the small-diameter O-ring 54.

  By the large and small O-rings 53 and 54, vibration at the time of contact between the dress plate 41 and the polishing pad 36 is absorbed, and the dress plate 41 is smoothly tilted with respect to the rotation shaft 43. That is, the large and small O-rings 53, 54 function as a backlash preventing portion that prevents backlash of the dress plate 41 when the inclination of the dress plate 41 is changed by being crushed according to the pressing of the polishing pad 36. . Further, on the outer peripheral side of the lower surface of the base plate 42, a restricting portion 65 that restricts the inclination of the base plate 42 to a predetermined angle (for example, 1 ° to 2 °) is provided. The restricting portion 65 projects annularly from the lower surface of the flat portion 55 so as to abut against the upper surface of the support portion 51 of the rotating shaft 43 when the base plate 42 is inclined at a predetermined angle or more.

  The skirt portion 56 of the base plate 42 is formed so as to cover the side of the support portion 51 of the rotation shaft 43 and the upper end portion 67 of the housing 47. The skirt portion 56 makes it difficult for slurry to enter the dress mechanism 12 during dressing. A discharge path 68 for discharging slurry that has entered the dressing mechanism 12 to the outside is formed in the upper end portion 67 of the housing 47, and further, between the support portion 51 of the rotating shaft 43 and the upper end portion 67 of the housing 47. A labyrinth structure 69 that restricts entry of slurry into the back of the dress mechanism 12 is formed. Furthermore, on the upper surface of the support portion 51 of the rotating shaft 43, the intrusion of slurry to the spherical seat 52 side is prevented by the O-rings 53 and 54.

  As shown in FIG. 2B, in the dress mechanism 12, when the dress surface 49 of the dress plate 41 comes into contact with the polishing surface 37 of the polishing pad 36, the surface of the polishing surface 37 is contacted by the contact resistance between the dress surface 49 and the polishing surface 37. The dress plate 41 is tilted by an angle θ following the uneven shape. When the dress plate 41 tilts counterclockwise in the figure, the left half of the dress plate 41 tilts downward with the spherical seat 52 as a fulcrum while crushing the left half of the large-diameter O-ring 53 in the figure. Is done. At the same time, the right half of the dress plate 41 is tilted upward with the spherical seat 52 as a fulcrum while crushing the small-diameter O-ring 54 around the connecting bolt 63 on the right side of the figure.

  Since the dress plate 41 is tilted while the large and small O-rings 53 and 54 are crushed, the vibration during dressing is absorbed, and the dress surface 49 can smoothly follow the surface shape of the polishing surface 37. In this case, since the O-rings 53 and 54 are formed more flexibly than the polishing pad 36, the polishing pad 36 side is deformed instead of the dress plate 41 tilting when the dress surface 49 and the polishing surface 37 come into contact with each other. There is no. Further, since the tilt angle of the dress plate 41 is limited by the restricting portion 65 provided on the base plate 42, the dress plate 41 does not hit the polishing pad 36 too much and is not partly polished.

  As described above, the tilt varying mechanism 44 in the present embodiment includes the spherical seat 52 of the support portion 51 of the rotating shaft 43, the restriction portion 65 of the base plate 42, and the large and small O-rings 53 and 54. The tilt varying mechanism 44 is not limited to the above configuration, and may be configured so that the dress plate 41 can tilt along the polishing surface 37 of the polishing pad 36 by the contact resistance between the dress surface 49 and the polishing surface 37. Any configuration may be used.

  By the way, when the dress plate 41 and the polishing pad 36 are rotated in the opposite directions at the time of dressing, the dress plate 41 is dragged to the polishing pad 36 while being tilted in one direction. Will not be followed. Then, since the polishing pad 36 is dressed with the dress plate 41 tilted in one direction, concentric striped patterns are formed on the polishing surface 37. In this embodiment, since the dress plate 41 is rotated in the same direction as the polishing pad 36, the contact resistance between the dress surface 49 and the polishing surface 37 does not become too large, and the polishing mechanism 36 is used by the dress mechanism 12. Is dressed well.

  A polishing pad dressing method will be described with reference to FIG. FIG. 3 is an explanatory diagram of a polishing pad dressing method according to the present embodiment. Note that the polishing pad dressing method described below is merely an example, and any method may be used as long as the polishing pad is dressed using the dressing mechanism according to the present embodiment.

  As shown in FIG. 3A, the dress plate 41 and the polishing pad 36 are rotated in the same direction, and the center of the polishing surface 37 of the polishing pad 36 coincides with the center of the dress surface 49 of the dress plate 41 by the radial movement means 15. So positioned. Then, the polishing pad 36 is brought close to the dress plate 41 by the polishing feeding means 14, and the polishing surface 37 of the polishing pad 36 is brought into contact with the dress surface 49 of the dress plate 41 (starting step). At this time, due to the contact resistance between the polishing surface 37 and the dress surface 49, the dress plate 41 is tilted following the uneven shape of the polishing surface 37, and the polishing surface 37 and the dress surface 49 are rotationally contacted in a parallel state.

  Next, as shown in FIG. 3B, the polishing pad 36 is moved to the left side in the figure by the radial direction moving means 15 while the dress plate 41 and the polishing pad 36 are in contact with each other. Accordingly, the dress plate 41 is moved radially outward relative to the polishing pad 36 while the dress plate 41 is tilted following the uneven shape of the polishing surface 37. Then, when the outer periphery of the polishing pad 36 reaches the center of the dress plate 41, the polishing pad 36 is moved in a direction away from the dress plate 41 by the polishing feeding means 14, and the polishing is finished (end step). .

  When the polishing pad 36 and the dress plate 41 are relatively moved in the radial direction, the rotational speed of the dress plate 41 is controlled to increase as the contact position between the dress plate 41 and the polishing pad 36 moves to the outer peripheral side. As a result, the variation in the circumferential speed difference (relative circumferential speed) between the dress plate 41 and the polishing pad 36 due to the difference in speed between the center and the outer periphery of the polishing pad 36 is reduced. Therefore, regardless of the contact position between the polishing pad 36 and the dress plate 41, the polishing surface 37 is rotationally contacted with the dress surface 49 with a uniform speed difference. In this way, the polishing surface 37 and the dress surface 49 are in a parallel state, and the polishing surface 37 is dressed at a constant relative speed in the radial direction of the polishing pad 36, and the entire polishing surface 37 is satisfactorily dressed by the dress plate 41. .

  Next, as shown in FIG. 3C, when the polishing pad 36 is separated from the dress plate 41, the center of the polishing surface 37 of the polishing pad 36 is again set to the center of the dress surface 49 of the dress plate 41 by the radial movement means 15. Positioning to match, the operations of FIGS. 3A and 3B are repeated. In the above-described dressing method of the polishing pad 36, the rotational speed of the dress plate 41 is variable. However, the present invention is not limited to this configuration. Based on the positional relationship recognized by the positional relationship recognition unit 27 (see FIG. 1), the dress plate 41 and the dress plate 41 and the polishing pad 36 have a uniform speed difference in the circumferential direction in the radial direction of the polishing pad 36. For example, instead of changing the rotation speed of the dress plate 41, the rotation speed of the polishing pad 36 may be changed.

  As described above, according to the dressing mechanism 12 according to the present embodiment, the dress plate 41 is supported on the spherical shaft 52 so as to be tiltable to the rotating shaft 43, so that the dress plate 41 is placed on the polishing surface 37 of the polishing pad 36. When the dress surface 49 comes into contact, the inclination of the dress surface 49 is varied following the surface shape of the polishing surface 37. At this time, since the backlash when the dress plate 41 is tilted is prevented, the dress surface 49 can smoothly follow the surface shape of the polishing surface 37. For this reason, since the polishing surface 37 of the polishing pad 36 and the dress surface 49 of the dress plate 41 are in contact with each other in parallel, the entire dress surface 49 can be uniformly applied to the polishing surface 37. You can dress evenly. Therefore, the slurry enters and discharges between the polishing pad 36 and the plate-like workpiece W, and the new slurry is fixed on the polishing surface 37 of the polishing pad 36, so that the plate-like workpiece W is polished well. The

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the present embodiment described above, the polishing surface 37 of the polishing pad 36 and the dress surface 49 of the dress plate 41 are in contact with each other in parallel, but this parallel is not limited to a completely parallel state. The polishing surface 37 and the dressing surface 49 may be parallel as long as the entire polishing surface 37 can be dressed substantially uniformly.

  Further, in the above-described embodiment, the polishing feeding means 14 is configured to make the polishing means 13 approach and separate from the chuck table 11, but the present invention is not limited to this configuration. The polishing feed means 14 may be configured to make the polishing means 13 relatively close to and away from the chuck table 11, and may make the chuck table 11 approach and separate from the polishing means 13.

  In the above-described embodiment, the radial moving means 15 is configured to move the polishing means 13 in the radial direction of the polishing pad 36 with respect to the chuck table 11 (dressing mechanism 12). However, the present invention is not limited to this configuration. . The radial direction moving means 15 may be configured to move the polishing means 13 relative to the chuck table 11 (dressing mechanism 12) in the radial direction of the polishing pad 36, and polish the chuck table 11 (dressing mechanism 12). The polishing pad 36 may be moved in the radial direction with respect to the means 13.

  In the above-described embodiment, the polishing unit 13 is provided with the pressure detection unit 24. However, the present invention is not limited to this configuration. The pressure detection unit 24 may be configured to detect the pressure of the polishing pad 36 and may be provided in the dressing mechanism 12.

  In the above-described embodiment, the rotational speed of the dress plate 41 and the polishing pad 36 is variable according to the contact position between the dress plate 41 and the polishing pad 36. However, the present invention is not limited to this configuration. Even if the rotational speed is not changed, the entire polishing surface 37 can be satisfactorily dressed by the dress plate 41 only by tilting the dress plate 41 following the uneven shape of the polishing surface 37 of the polishing pad 36.

  In the above-described embodiment, the backlash prevention unit is configured using the large and small O-rings 53 and 54. However, the present invention is not limited to this configuration. The backlash prevention unit may be configured to prevent backlash when the inclination of the dress plate 41 is varied, and a buffer material that absorbs backlash may be used instead of the O-rings 53 and 54.

  In the present embodiment described above, the base plate 42 is provided with the restricting portion 65. However, the present invention is not limited to this configuration. The limiting unit 65 may be configured to limit the inclination of the dress plate 41, and may be provided on the support unit 51 side of the rotating shaft 43, for example.

  In the above-described embodiment, the dress plate 41 is tiltably supported on the rotation shaft 43 by the spherical surface portion 57 provided on the base plate 42 and the spherical seat 52 provided on the support portion 51 of the rotation shaft 43. However, the present invention is not limited to this configuration. A spherical seat 52 may be provided on the base plate 42, and a spherical portion 57 may be provided on the support portion 51 of the rotating shaft 43.

  As described above, the present invention has an effect that the polishing surface can be uniformly dressed without creating unevenness on the polishing surface of the polishing pad, and in particular, the wafer is polished while supplying the slurry. Useful for polishing equipment.

DESCRIPTION OF SYMBOLS 1 Polishing apparatus 11 Chuck table 12 Dress mechanism 13 Polishing means 14 Polishing feed means 15 Radial direction moving means 21 Polishing feed control part 22 Polishing pad rotation control part 23 Dress plate rotation control part 24 Pressure detection part 25 Polishing pad rotation variable part 26 Dress Rotation variable portion 29 Holding surface of chuck table 31 Spindle 32 Platen 33 Platen mounting surface 36 Polishing pad 37 Polishing surface 41 Dress plate 43 Rotating shaft 44 Inclination variable mechanism 46 Adjustment portion 49 Dress surface 65 Limiting portion W Plate work

Claims (4)

A dressing mechanism for dressing a polishing pad having a polishing surface for polishing a plate-like workpiece, a chuck table having a holding surface for holding a plate-like workpiece, and the polishing pad for polishing a plate-like workpiece held by the chuck table A polishing means for rotatably mounting, a polishing feed means for moving the polishing means toward and away from the chuck table, a polishing means and the chuck table, or a polishing means and the dressing mechanism having a diameter of the polishing pad. A radial movement means for relatively moving in a direction, and a polishing apparatus comprising:
The polishing means includes
A disk-shaped platen having a mounting surface for mounting the polishing pad;
A spindle for rotating the platen,
The dress mechanism is
A disc-shaped dress plate having a dress surface in contact with the polishing surface;
A rotating shaft coupled to the dress plate and rotating about the center of the dress plate;
An adjustment unit that adjusts the rotation axis of the dress plate and the mounting surface of the platen to an orthogonal inclination;
An inclination variable mechanism that is disposed between the rotating shaft and the dress plate and tilts the dress surface following the inclination of the polishing surface;
The variable tilt mechanism is
A spherical seat with a fulcrum on the center axis of the dress plate, the rotation axis supporting the dress plate;
A backlash preventing portion for preventing backlash of the dress plate when the dress plate supported by the spherical seat is tilt-variable by pressing of the polishing pad;
A limiting portion that limits the tilt of the dress plate that is tilt-variable by pressing of the polishing pad,
A polishing apparatus characterized in that the polishing surface in a dress and the dress surface are parallel to each other. The polishing means or the dressing mechanism includes a pressure detector that presses the polishing pad,
The pressure of the polishing pad detected by the pressure detection unit is monitored, and the pressure value detected by the pressure detection unit does not exceed a preset pressure setting value during a dress in which the dress surface is brought into contact with the polishing surface. The polishing apparatus according to claim 1, further comprising a polishing feed control unit that controls the polishing feed means. A dress plate rotation control unit for controlling the rotation speed of the dress plate;
A polishing pad rotation control unit for controlling the rotation speed of the polishing pad;
A positional relationship recognition unit for recognizing a positional relationship between the polishing pad and the dress plate;
Based on the positional relationship recognized by the positional relationship recognition unit, the dress plate and the polishing pad are rotated so that the speed difference in the circumferential direction between the dress plate and the polishing pad is uniform in the radial direction of the polishing pad. The polishing apparatus according to claim 1, wherein the speed is controlled by the dress plate rotation control unit and the polishing pad rotation control unit. A polishing pad dressing method using the polishing apparatus according to any one of claims 1 to 3 ,
Rotating the polishing pad and the dress plate in the same direction, using the radial movement means to match the center of the dress surface with the center of the polishing surface, and starting to contact the dress surface with the polishing surface Process,
After the starting step, the dressing plate is moved toward the outside of the polishing pad using the radial moving means, and the polishing pad and the dressing surface are moved when the center of the dressing plate comes to the outer periphery of the polishing surface. And an end step to finish polishing by moving in the direction of separating,
A repetition step of repeating the start step and the end step a specified number of times;
Polishing pad dressing method performed by the method.

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