JP2013094925A - Correction carrier and polishing device - Google Patents

Abstract

A correction carrier and a polishing apparatus capable of flattening a polishing surface of a surface plate with high accuracy are provided.
A modified carrier 1 having through holes 10a, 10b, 10c, and 10d in the thickness direction used for flatly polishing polishing surfaces 25a and 27a of surface plates 25 and 27 of a double-side polishing apparatus 22. In addition, the through holes 10a, 10b, 10c, and 10d are located at positions avoiding the center of the main surface.
[Selection] Figure 1

Description

  The present invention relates to a correction carrier and a polishing apparatus used for correcting a polishing surface of a surface plate provided in the polishing apparatus.

2. Description of the Related Art Conventionally, in the process of manufacturing a semiconductor or a crystal resonator, the wafer surface is polished in order to remove scratches and distortions on the surface of the wafer serving as a base plate.
A polishing apparatus is used for polishing the wafer surface. The polishing apparatus includes a double-side polishing apparatus that simultaneously polishes both sides of a wafer and a single-side polishing apparatus that polishes one side of a wafer. The double-side polishing apparatus is superior in thickness accuracy as compared with the single-side polishing apparatus, and is used for polishing a quartz wafer that is a base plate for manufacturing a quartz resonator.

  FIG. 13 is a perspective view of a conventional double-side polishing apparatus 22. The double-side polishing apparatus 22 includes a drive shaft 23 disposed at the rotation center, a sun gear 24 that is rotationally driven by the drive shaft 23, and an annular lower surface plate 25 that is provided concentrically with the sun gear 24 around the sun gear 24. The internal gear 26 is disposed around the lower surface plate 25 and is concentric with the sun gear 24 and is driven to rotate, and the annular upper surface plate 27 is disposed above the lower surface plate 25. Between the sun gear 24 and the internal gear 26, a carrier 21 holding a workpiece W such as a quartz wafer is disposed.

  In order to polish the workpiece W, the workpiece W is accommodated in the holding hole 21p of the carrier 21, and the carrier 21 is incorporated so that the gear 21g provided on the outer peripheral surface of the carrier 21 meshes with the sun gear 24 and the internal gear 26 simultaneously. . Further, the carrier 21 is sandwiched between the upper surface plate 27 and the lower surface plate 25 and a load is applied. Then, while supplying abrasive (slurry) to the polishing surface, a drive mechanism (not shown) is driven to rotate the sun gear 24, internal gear 26, upper surface plate 27, and lower surface plate 25. Accordingly, as shown in FIG. 14, the carrier 21 meshing with the sun gear 24 and the internal gear 26 performs a so-called planetary motion that rotates while rotating around the sun gear 24. The upper and lower surface plates 25 and 27 polish the work W by rotating in the opposite direction or the same direction.

  When iron is used as the material for the upper and lower surface plates, the apparatus is called a lapping machine, and the workpiece W can be wrapped by the surface plate. On the other hand, when a pad made of resin or the like is attached to the surface plate, the apparatus is called a polish plate, and the work W can be polished on the surface plate. For the lapping machine, a carbon or alumina abrasive with a particle size of several μ to several tens of μm is used for the lapping machine, and cerium oxide with a particle diameter of about 1 μm or recently zirconia is used for the polishing machine. The

  In such a polishing apparatus, when a quartz wafer serving as a base plate of a quartz oscillator, which is a precision component, is polished as a workpiece, it is required to polish the workpiece flatly with high accuracy. When a workpiece is polished with a surface plate, the polishing surface of the surface plate is transferred to the workpiece. Therefore, the flatness of the polishing surface of the surface plate is necessary in order to cope with the higher accuracy of the workpiece, which is increasingly demanded year by year. Must be maintained and managed with high accuracy.

  However, the polishing surface of the surface plate is scraped or deformed as the workpiece is repeatedly polished. Therefore, after polishing for a certain number of times and time, an operation for correcting the polishing surface of the surface plate to be flat is required. This operation is called “fixing the surface plate”.

  When performing the surface plate correction, the carrier is taken out from the polishing apparatus, and a correction carrier (hereinafter referred to as “correction carrier”) is set instead. Then, as in the case of workpiece polishing, a load is applied to the surface plate, and the correction carrier and the surface plate are rotated while supplying an abrasive to the polishing surface. This rotation is performed for several tens of minutes to several hours.

  The correction carrier has a thickness of 20 to 30 mm, which is thicker than the polishing carrier, in order to give rigidity and wear due to the correction of the surface plate. In addition, a through-hole is provided in the central portion of the main surface of the correction carrier so that the abrasive is evenly distributed over the polishing surface.

  As a conventional correction carrier, for example, Patent Document 1 discloses that both the upper and lower surface plates are adjusted by adjusting the correction amount of the upper and lower surface plates by changing the area of the hole provided in the central portion of the correction carrier on both main surfaces. It describes that the surface plate is corrected efficiently and economically without the need for sliding.

JP 2000-218521 A

In order to satisfy the currently required accuracy of the wafer, when the diameter of the surface plate is about 650 mm, the flatness needs to be 1 μm or less. However, if a hole is provided in the center of the correction carrier as in Patent Document 1, the surface of the surface plate is not an ideal plane in reality, so that the correction carrier is the cup wheel of the curve generator shown in FIG. Thus, the platen is polished in a state slightly inclined with respect to the surface of the platen according to the same principle as when the convex lens is polished. For this reason, the center part of the width direction of a surface plate becomes a convex shape slightly, and flatness cannot be obtained. Also, if there is a hole in the center of the correction carrier, the time for the center part of the surface plate width to contact the correction carrier (that is, the distance moved relatively) becomes small, so the processing amount of the center part of the surface plate width is small. Become. This also contributes to the convex shape on the surface plate.
The present invention has been made to solve the above problems, and an object of the present invention is to provide a correction carrier and a polishing apparatus capable of flattening the polishing surface of a surface plate with high accuracy.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
[Application Example 1] A correction carrier having a through hole in the thickness direction, which is used to flatly polish a polishing surface of a surface plate of a polishing apparatus, and the through hole avoids the center of the main surface. Corrective carrier characterized by being in position.
According to the present invention, since the through-hole penetrating in the thickness direction is provided at a position avoiding the center of the main surface of the correction carrier, it is possible to prevent the center portion of the surface plate width from becoming a convex shape. The polished surface of the board can be flattened with high accuracy.

Application Example 2 The correction carrier according to Application Example 1, wherein a plurality of the through holes are provided in a rotationally symmetrical manner in a plan view.
According to the present invention, since the plurality of through holes are provided in a rotationally symmetrical manner in a plan view, the polishing surface of the surface plate of the polishing apparatus can be uniformly polished and corrected to be flat.

Application Example 3 A polishing apparatus including the correction carrier according to Application Example 1 or 2.
According to the present invention, the polishing apparatus can uniformly polish the polishing surface of the surface plate of the polishing apparatus with the correction carrier, and can correct the polishing surface to be flat.

Application Example 4 The polishing apparatus according to Application Example 3, wherein at least a part of the through hole passes through the inner peripheral end of the surface plate in a plan view during planetary motion.
According to the present invention, since at least a part of the through hole passes through the inner peripheral end of the surface plate in plan view during planetary motion, the amount of polishing in the vicinity of the inner peripheral end can be reduced. Therefore, when the surface plate having a sag near the inner peripheral edge is corrected by the correction carrier, the polished surface can be corrected with high accuracy and flatness.

Application Example 5 The polishing apparatus according to Application Example 3, wherein at least a part of the through hole passes through an outer peripheral end portion of the surface plate in a plan view during planetary motion.
According to the present invention, since at least a part of the through hole passes through the outer peripheral end portion of the surface plate in plan view during planetary motion, the amount of polishing in the vicinity of the outer peripheral end portion can be reduced. Therefore, when the surface plate in which the sag occurs in the vicinity of the outer peripheral end is corrected with the correction carrier, the polished surface can be corrected with high accuracy and flatness.

Application Example 6 The polishing apparatus according to Application Example 3, wherein all of the through holes always overlap the polishing surface in a plan view during planetary motion.
According to the present invention, since all of the through-holes always overlap the polishing surface in a plan view during planetary motion, it is possible to increase the polishing amount in the vicinity of the inner peripheral edge and the outer peripheral edge of the surface plate. . Therefore, when the surface plate where the inner peripheral end portion and the outer peripheral end portion are thicker than other portions is corrected with the correction carrier, the polished surface can be corrected with high accuracy and flatness.

It is a top view of the correction carrier which concerns on embodiment of this invention. It is AA sectional view taken on the line of the correction carrier shown in FIG. It is a perspective view of the double-side polish apparatus with which the correction carrier which concerns on the embodiment was set. It is a top view of the correction carrier which concerns on a modification. It is the top view of the conventional correction carrier, and its BB sectional drawing. It is the top view of the correction carrier which concerns on this invention, and its CC sectional view. It is a figure which shows the dimension of the surface plate used for the surface plate correction. (A) is DD sectional view before correction of the surface plate shown in FIG. 7, (b) is DD of the surface plate shown in FIG. 7 after surface plate correction using the conventional correction carrier. It is line sectional drawing, (c) is DD line sectional drawing of the surface plate shown in FIG. 7 after surface plate correction | amendment using the correction carrier which concerns on this invention. It is a typical top view which shows a part of lower surface plate part of the state which set the correction carrier to the double-side polish apparatus. It is the EE sectional view taken on the line shown in FIG. It is a typical top view which shows a part of lower surface plate part of the state which set the correction carrier to the double-side polish apparatus. It is the EE sectional view taken on the line shown in FIG. It is a perspective view of the conventional double-side polishing apparatus. It is operation | movement explanatory drawing of the double-side polish apparatus shown in FIG. It is explanatory drawing of the principle of operation of a curve generator.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a plan view of a correction carrier 1 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the correction carrier 1 shown in FIG.

  As shown in FIG. 1, the correction carrier 1 has a disk shape, and a gear 12 is provided on the outer peripheral surface. The main surface of the correction carrier 1 is provided with through holes 10a, 10b, 10c, 10d penetrating in the thickness direction. These through holes 10 a, 10 b, 10 c, and 10 d are disposed at positions avoiding the center of the main surface and are rotationally symmetrical in plan view with respect to the center of the main surface of the correction carrier 1. Further, both main surfaces of the correction carrier 1 communicate with the through holes 10a, 10b, 10c, and 10d, and the through holes 10a, 10b, 10c, and 10d and the outer peripheral end portion of the correction carrier 1 so that an abrasive is provided. Grooves 14 are provided for evenly spreading the polished surface. As shown in FIG. 3, the correction carrier 1 is set in place of a carrier for polishing a workpiece when the polishing surfaces 25 a and 27 a of the upper and lower surface plates 25 and 27 of the double-side polishing apparatus 22 are polished and corrected. .

  FIG. 3 is a perspective view of the double-side polishing apparatus 22 in which the correction carrier 1 is arranged. A driving shaft 23 is disposed at the center of the double-side polishing apparatus 22, and a sun gear 24 that is rotationally driven by the driving shaft 23 is disposed. An annular lower surface plate 25 is provided around the sun gear 24 concentrically with the sun gear 24. An internal gear 26 that is disposed concentrically with the sun gear 24 and is rotationally driven is provided outside the outer periphery of the sun gear 24 and around the lower surface plate 25. An annular upper surface plate 27 is provided above the lower surface plate 25. The correction carrier 1 is disposed between the sun gear 24 and the internal gear 26 in place of the carrier for workpiece polishing.

  Next, the operation when the polishing surfaces 25a and 27a of the upper and lower surface plates 25 and 27 are corrected using the correction carrier 1 will be described. First, a work polishing carrier (not shown) is removed from the double-side polishing apparatus 22 shown in FIG. Instead, the correction carrier 1 is incorporated so that the gear 12 of the correction carrier 1 meshes simultaneously with the sun gear 24 and the internal gear 26, and the correction carrier 1 is sandwiched between the upper surface plate 27 and the lower surface plate 25, The correction carrier 1 and the upper and lower surface plates 25 and 27 are brought into contact with each other. Then, while supplying the abrasive to the upper and lower surface plates 25 and 27, the sun gear 24, the internal gear 26, and the upper and lower surface plates 25 and 27 are rotated to cause the correction carrier 1 to perform a planetary motion.

  In the present embodiment, the polishing surfaces 25a and 27a of the upper and lower surface plates 25 and 27 are polished using the modified carrier 1 provided with the through holes 10a, 10b, 10c, and 10d at positions avoiding the center of the main surface. The correction carrier 1 contacts the upper and lower surface plates 25 and 27 in parallel. Moreover, the time (distance) for which the correction carrier 1 is in contact with the center part of the surface plate width becomes long. For this reason, it can prevent that the center part of the surface plate width becomes convex shape, and can make the polishing surfaces 25a and 27a of the upper and lower surface plates 25 and 27 flat with high accuracy. Further, since the plurality of through holes 10a, 10b, 10c, and 10d are provided in a rotationally symmetrical manner in a plan view, the polishing surfaces 25a and 27a of the upper and lower surface plates 25 and 27 can be uniformly polished and corrected to be flat. .

The shape and number of the through holes provided in the correction carrier are not limited to those shown in FIG. 1, and any shape can be used as long as they are provided rotationally symmetrically in a plan view at a position avoiding the center of the main surface. It may be a through hole. For example, as shown in FIG. 4, it may be a modified carrier 1A provided with three through holes 10e, 10f, and 10g along the circumference.
Further, the shape of the through hole may be, for example, an elliptical shape or a polygonal shape in plan view.

  Next, a comparison result with a conventional correction carrier will be described with reference to FIGS. FIG. 5 is a plan view of a conventional correction carrier 21A having an outer diameter of 144 mm and a through hole 11 having a diameter of 94 mm in the center and a cross-sectional view taken along the line BB. FIG. 6 is a plan view of the correction carrier 1A according to the present invention, in which the outer diameter is 144 mm, and three through holes 10e, 10f, and 10g are provided at positions avoiding the center of the main surface, and C FIG.

  FIG. 8 shows a result of polishing and correcting a surface plate having an outer diameter of 660 mm and an inner diameter of 424 mm shown in FIG. 7 using these correction carriers 21A and 1A. FIG. 8A is a cross-sectional view taken along the line D-D before the surface plate shown in FIG. 7 is corrected, and FIG. 8B is a view shown in FIG. 7 after the surface plate is corrected using the conventional correction carrier 21A. FIG. 8C is a sectional view taken along the line DD of the surface plate shown in FIG. 7 after the surface plate is corrected using the modified carrier 1A according to the present invention. As shown in FIG. 8 (a), when there is a difference in thickness of 5 μm before the surface plate is corrected, as shown in FIG. 8 (b), when the correction is made using the conventional correction carrier 21A. While the thickness difference is 2 μm, as shown in FIG. 8C, when the correction carrier 1A according to the present invention is used for correction, the thickness difference is 0.5 μm. It has become. Thus, it was confirmed that when the conventional correction carriers 21A and 1A having the same diameter are used, the correction carrier 1A according to the present invention can flatten the polishing surface of the surface plate.

  If there are irregularities on the outer peripheral edge or inner peripheral edge of the polishing surface of the surface plate before correction, the surface plate is corrected using a correction carrier in which through holes are arranged so that the polishing amount for the concave portion is reduced. By doing so, the flatness of the polished surface can be further increased.

  For example, when the upper and lower surface plates 25 and 27 having a sag at the inner peripheral edge are corrected using the correction carrier 1 shown in FIG. The through holes 10a, 10b, 10c, and 10d may be arranged so that at least a part of 10a, 10b, 10c, and 10d passes through the inner peripheral ends of the upper and lower surface plates 25 and 27 in plan view.

  In addition, when sagging occurs at the outer peripheral ends of the upper and lower surface plates 25 and 27, during the planetary movement of the correction carrier 1, at least a part of the through holes 10a, 10b, 10c, and 10d is vertically fixed in plan view. The through holes 10a, 10b, 10c, and 10d of the correction carrier 1 are preferably arranged so as to pass through the outer peripheral ends of the boards 25 and 27.

  FIG. 9 shows through-holes 10a, 10b, which are arranged so that at least a part thereof passes through the outer peripheral end and inner peripheral end of the upper and lower surface plates 25, 27 in plan view during the planetary motion as described above. It is a typical top view which shows a part of lower surface plate 25 part of the state which set the correction carrier 1 which has 10c, 10d to the double-side polish apparatus 22. FIG. 10 is a cross-sectional view taken along line EE shown in FIG. In these drawings, the upper surface plate 27 is not shown.

As shown in these drawings, the following positional relationship is established in the modified carrier 1 having the through holes 10a, 10b, 10c, and 10d as described above.
(The shortest distance during planetary motion between the meshing portion 13 meshing with the sun gear 24 and the through holes 10a, 10b, 10c, 10d) a ≦ the distance between the meshing portion 13 and the inner peripheral end of the lower surface plate 25 B) and
(The longest distance during planetary motion between the meshing part 13 and the through holes 10a, 10b, 10c, 10d) c ≧ (distance between the meshing part 13 and the outer peripheral end of the lower surface plate 25) d

  By arranging the through holes 10a, 10b, 10c, and 10d in the modified carrier 1 in this way, when the sagging occurs in the vicinity of the inner peripheral end portions or the outer peripheral end portions of the upper and lower surface plates 25 and 27, Since the polishing amount at the peripheral end portion and the outer peripheral end portion can be reduced as compared with other portions, the polishing surface 25a can be efficiently and flatly corrected with high accuracy.

  On the other hand, when the upper and lower surface plates 25 and 27 whose inner peripheral end portions are thicker than the other portions are corrected by the correction carrier 1 shown in FIG. When the holes 10a, 10b, 10c, and 10d are arranged so as to pass closer to the outer periphery of the upper and lower surface plates 25 and 27 than the position overlapping the inner peripheral end portions of the upper and lower surface plates 25 and 27 in plan view. Good.

  When the outer peripheral end portions of the upper and lower surface plates 25 and 27 are thicker than the other portions, the through holes 10a, 10b, 10c and 10d are formed at the outer peripheral end portions of the upper and lower surface plates 25 and 27 during the planetary motion. It is good to arrange | position so that it may pass near inner periphery of the upper and lower surface plates 25 and 27 rather than the position which overlaps by planar view.

  Further, when both the outer peripheral end portions and the inner peripheral end portions of the upper and lower surface plates 25 and 27 are thicker than the other portions, all of the through holes 10a, 10b, 10c and 10d are in the planetary motion. It is good to arrange | position so that it may always overlap with polishing surface 25a, 27b by planar view.

  FIG. 11 shows a double-side polishing apparatus in which the correction carrier 1 having the through holes 10a, 10b, 10c, and 10d arranged so that all of them always overlap with the polishing surfaces 25a and 27b in a plan view during the planetary motion as described above. FIG. 22 is a schematic plan view showing a part of the lower surface plate 25 portion set in the state of 22; 12 is a cross-sectional view taken along line FF shown in FIG. In these drawings, the upper surface plate 27 is not shown.

As shown in these drawings, the following positional relationship is established in the modified carrier 1 having the through holes 10a, 10b, 10c, and 10d as described above.
(The shortest distance during planetary motion between the meshing portion 13 and the through hole) e> (distance between the meshing portion 13 and the inner peripheral end of the lower surface plate 25) f, and
(The longest distance during planetary motion between the meshing portion 13 and the through hole) g <(distance between the meshing portion 13 and the outer peripheral edge of the lower surface plate 25) h

  By arranging the through holes 10a, 10b, 10c, 10d in the correction carrier 1 in this way, when convex portions are generated in the vicinity of the inner peripheral end portions or the outer peripheral end portions of the upper and lower surface plates 25, 27, Since the amount of polishing at the inner peripheral end and the outer peripheral end can be increased as compared with other portions, the polishing surface 25a can be efficiently and flatly corrected with high accuracy.

  In the above-described embodiment, the quartz wafer is described as the workpiece to be polished. However, the workpiece to be polished is not limited to the quartz wafer. For example, a silicon wafer may be used.

In the above-described embodiment, the upper surface plate 27 and the lower surface plate 25 are configured to be rotationally driven during polishing. However, the present invention is not limited to this, and only the lower surface plate 25 is stopped while the upper surface plate 27 is stopped. It may be configured to rotate.
In the above-described embodiment, the case where the correction carrier 1 is used for the double-side polishing apparatus 22 has been described. However, the correction carrier 1 can also be used for a single-side polishing apparatus.

1, 1 A... Modified carrier, 10 a, 10 b, 10 c, 10 d, 10 e, 10 f, 10 g ......... through hole, 12 ......... gear, 13 ......... meshing part, 14 ......... groove, 22 ... ... Double-side polishing device, 23 ... Drive shaft, 24 ... Sun gear, 25 ... Lower plate, 26 ... Internal gear, 27 ... Upper plate, 25a, 27a ... Polished surface.

Claims (6)

A correction carrier having a through-hole in the thickness direction, used to polish the polishing surface of the surface plate of the polishing apparatus flatly,
The correction carrier according to claim 1, wherein the through hole is at a position avoiding the center of the main surface.   The correction carrier according to claim 1, wherein a plurality of the through holes are provided in a rotationally symmetrical manner in a plan view.   A polishing apparatus comprising the correction carrier according to claim 1.   The polishing apparatus according to claim 3, wherein at least a part of the through hole passes through an inner peripheral end of the surface plate in a plan view during planetary motion.   The polishing apparatus according to claim 3, wherein at least a part of the through hole passes through an outer peripheral end portion of the surface plate in a plan view during planetary motion.   The polishing apparatus according to claim 3, wherein all of the through holes always overlap the polishing surface in a plan view during planetary motion.

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