JPH11300609A - Substrate polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate polishing device allowing a grinding wheel to follow a warp of a polished surface of a polished substrate even with the warp and absorbing reaction generated by friction between the polished substrate and the grinding wheel in course of polishing so as to being the surface of the grinding wheel appropriately in contact with the surface of the polished substrate to attain uniform polishing. SOLUTION: In a substrate polishing device making a grinding wheel 1 abut to a substrate 5 to be polished to polish the substrate 5 by the relative motion of the substrate 5 tu be polished and grinding wheel 1, the grinding wheel 1 is fitted to a support body 2 through an elastic body 3. The grinding wheel 1 comprises a large number of pellet-like grindstones arranged in annular shape, and each pellet-like grindstone is fitted to the support body 2 through the elastic body 3. The grinding wheel 1 is supported to the support body 2 through a spherical seat bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate polishing apparatus for polishing a substrate to be polished by bringing a grindstone into contact with a substrate to be polished such as a semiconductor wafer or various disks, and polishing the substrate by a relative motion between the substrate and the grindstone. is there.

[0002]

2. Description of the Related Art Conventionally, there is a CMP apparatus as an apparatus for polishing a substrate to be polished such as a semiconductor wafer. The CMP apparatus abuts a substrate to be polished mounted on a rotating top ring on a polishing cloth surface of a turntable, and polishes the polishing surface of the substrate to be polished while supplying a slurry on the polishing cloth surface. It is configured so that However, in the polishing by the CMP apparatus, a step (unevenness) existing before polishing remains on the polished surface, and polishing with excellent step characteristics (accurate flatness) cannot be performed, and the consumption of slurry increases. However, there is a problem that running costs are increased.

[0003] Therefore, as a polishing apparatus capable of polishing with excellent step characteristics, a polishing apparatus which abuts a grindstone on a substrate to be polished as described above, and polishes the substrate to be polished by relative movement between the substrate and the grindstone. There is.

[0004]

However, since the polishing apparatus using the above-mentioned grindstone has a configuration in which a hard grindstone is fixed to a support made of a rigid body, when the polished surface of the substrate to be polished has a warp, However, there is a problem in that it does not move smoothly along this warped surface, making uniform polishing difficult.
Also, during polishing, the grindstone is strongly opposed to the surface of the substrate to be polished in the traveling direction by a reaction force due to friction with the substrate to be polished, and the rear side in the traveling direction is subjected to a force separating from the substrate to be polished. There is a problem that uniform polishing of the substrate to be polished becomes difficult.

The present invention has been made in view of the above problems, and eliminates the above-mentioned problems. Even if the polishing surface of the substrate to be polished has a warp, the grindstone can follow the warp and the grindstone being polished. It is an object of the present invention to provide a substrate polishing apparatus capable of absorbing a reaction force generated by friction between the substrate and a substrate to be polished, and allowing a grinding wheel surface to appropriately contact a substrate surface to be polished to perform uniform polishing.

[0006]

According to a first aspect of the present invention, a grindstone is brought into contact with a substrate to be polished, and the substrate is polished by relative motion between the substrate and the grindstone. In the above substrate polishing apparatus, the grindstone is supported by a support via an elastic body.

Further, in a substrate polishing apparatus for abrading a substrate to be polished by bringing a grindstone into contact with the substrate to be polished and polishing the substrate to be polished by a relative motion between the substrate and the grindstone, the grindstone is formed by a large number of pellet-shaped grindstones arranged in a ring. Wherein each of the pellet-shaped grinding wheels is supported by a support via an elastic body.

According to a second aspect of the present invention, there is provided a substrate polishing apparatus in which a grindstone is brought into contact with a substrate to be polished and the substrate is polished by relative movement between the substrate and the grindstone. Characterized by being supported by the support via

According to a third aspect of the present invention, there is provided a substrate polishing apparatus for abutting a grindstone on a substrate to be polished and polishing the substrate to be polished by relative movement between the substrate and the grindstone, wherein the grindstones are arranged in a ring. Made of a number of pellet-shaped whetstones,
Each of the pellet-shaped grinding wheels is supported by a support via a spherical bearing.

[0010] Further, the invention according to claim 4 is based on claim 2.
Alternatively, in the substrate polishing apparatus according to 3, the opposite side of the grinding wheel of the spherical seat bearing is supported by a support via an elastic body.

Further, in the substrate polishing apparatus according to the second or third aspect, the spherical seat bearing is formed of an elastic body.

Further, the invention described in claim 5 is the same as the invention described in claim 2.
Alternatively, in the substrate polishing apparatus according to 3, the grinding wheel side of the spherical seat bearing is supported by a support via an elastic body.

Further, in the substrate polishing apparatus according to any one of claims 2 to 5, a height adjusting means for adjusting the height of the grindstone is provided.

Further, in the substrate polishing apparatus according to any one of claims 3 to 5, a height adjusting means for adjusting the height of the grindstone is provided, and the amount of polishing of the substrate to be polished or the height of the grindstone is measured. The polishing surface of each whetstone is made uniform using height adjusting means.

The invention described in claim 6 is the third invention.
In the substrate polishing apparatus according to any one of the above-described embodiments, the constituent members including the grindstone and the support are combined as a grindstone holding structure, and the whole grindstone holding structure can be attached to and detached from the grindstone retainer. And

Further, in the substrate polishing apparatus according to the present invention, the grinding wheel retainer is supported on the rotating shaft via a spherical bearing.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a grindstone holding structure used in the substrate polishing apparatus of the present invention. FIG. 1 (a) is a side sectional view, and FIG. 1 (b) is a bottom view. The whetstone holding structure is a structure in which a flat annular whetstone 1 is attached to a disk-shaped support 2 via an elastic body 3 such as rubber. Reference numeral 4 denotes a rotating shaft, which is provided integrally with the support 2 here.

As described above, the support 2 is provided via the elastic body 3.
The annular grindstone 1 attached to the substrate is brought into contact with the polishing surface of the substrate 5 to be polished such as a semiconductor wafer, and water is supplied to the upper surface of the substrate 5 from a water supply pipe or the like (not shown). The substrate 5 to be polished is polished. At this time, an elastic body 3 is provided between the support 2 and the grindstone 1.
, The grindstone 1 can move smoothly along the warped surface even if the polished surface of the polished substrate 5 is warped, so that the polished substrate 5 can be uniformly polished.

FIG. 2 is a view showing another example of the structure of the grinding wheel holding structure used in the substrate polishing apparatus of the present invention. FIG. 2 (a) is a side sectional view, and FIG. 2 (b) is a bottom view. The present whetstone holding structure is a structure in which a number of pellet-shaped whetstones 10 are annularly arranged at equal intervals on the lower surface of a disk-shaped support 2, and each whetstone 10 is provided with a spring in a casing 11 attached to the lower surface of the support 2. Elastic body 1
It is housed and supported via 2. That is, here, the whetstone 1
Numeral 0 is indirectly supported by the support via the elastic body 12 and the casing.

As described above, the grindstone 10 housed and supported via the elastic body 12 in the casing 11 disposed annularly at equal intervals on the lower surface of the support 2 abuts on the polishing surface of the substrate 5 to be polished. Water is supplied to the upper surface of the polished substrate 5 from a water supply pipe or the like which is not used, and the polished substrate 5 is polished by rotating the rotating shaft 4 as shown by the arrow A. At this time, since the elastic body 12 is interposed between the casing 11 and the grindstone 10, even if the polished surface of the substrate 5 to be polished has a warp, the grindstone 10 can smoothly follow the warped surface and move, and the uniformity can be obtained. Polishing becomes possible.

FIG. 3 is a view showing another embodiment in which the grindstone 10 is accommodated and supported in a casing 11. The grindstone 10 is held by a holder 13, an elastic body 12 such as rubber is interposed between the holder 13 and the inner upper surface of the casing 11, and the grinding wheel 10 is placed between the outer peripheral surface of the holder 13 and the inner peripheral surface of the casing 11. An annular elastic body 14 such as a ring is interposed. This allows
The vertical force applied to the grindstone 10 is absorbed by the elastic body 12,
The lateral force applied to the grindstone 10 is absorbed by the elastic body 12.
That is, in this case, the vertical direction and the horizontal direction of the holding body 13 holding the grinding stone 10 are supported by the elastic bodies 12 and the elastic bodies 14. Thus, even if the polished surface of the substrate 5 to be polished has a warp, the grindstone 10 can move smoothly following the warped surface, and uniform polishing can be performed.

FIG. 4 is a side sectional view showing another example of the structure of the grinding wheel holding structure used in the substrate polishing apparatus of the present invention. In the present whetstone holding structure, the upper end surface of the holding body 13 holding the whetstone 10 is formed as a convex spherical surface, and the lower end of the supporting body 16 supporting the holding body 13 is formed in a concave shape so as to be in close contact with the spherical surface. The spherical seat bearing 15 is formed of a convex spherical surface at the upper end of the holder 13 and a concave spherical surface at the lower end of the support 16. That is, the grindstone side of the spherical bearing 15 is the holder 13, and the grindstone side is the support 16. In addition, whetstone 10
Is held in the large-diameter portion 11a below the casing 11, and the support 16 is accommodated in the small-diameter portion 11b above the casing 11, and moves up and down within a predetermined dimension. I can do it.

A piston 18 is accommodated above the small diameter portion 11b of the casing 11, and an elastic body 17 made of rubber or the like is interposed between the piston 18 and the support 16. A screw groove 19 for adjusting the height of the grindstone 10 is formed above the piston 18. By rotating the height adjustment knob 20, the screw groove 19 is formed on the inner periphery of the upper end of the small diameter portion 11 b. The piston 18 moves up and down by screwing into a thread groove (not shown) formed on the surface. The grindstone 1 held by the holder 13 in conjunction with the vertical movement of the piston 18
0 also moves up and down, so that the height of the grindstone 10 can be adjusted.

A nut is arranged at the upper end of the casing 11 in place of the height adjusting knob 20, and the peripheral thread of the small diameter portion 11b of the casing 11 is eliminated. The height of the grindstone 10 can be adjusted by rotating the nut. Further, 14 is the same as the case of FIG.
Is an annular elastic body such as an O-ring interposed between the inner peripheral surface of the holding member 13 and the outer peripheral surface of the holding member 13, and 21 is a fall prevention plate for preventing the holding member 13 and the like from falling.

In the whetstone holding structure having the above structure, the whetstone 1
0 is in contact with the upper surface of the substrate 5 to be polished, water is supplied to the upper surface of the substrate 5 to be polished from a water supply pipe or the like (not shown), and the casing 11 or the substrate 5 to be polished or the casing 11 and the substrate 5 to be polished are Then, the substrate 5 to be polished is polished by mutual relative movement. At this time, the vertical reaction force applied to the grindstone 10 is absorbed by the elastic body 17, and the lateral reaction force due to the friction between the grindstone 10 and the substrate 5 to be polished is absorbed by the elastic body 14. Thus, even if the polished surface of the substrate 5 to be polished has a warp, the grindstone 10 can smoothly follow and move along the polished surface, and uniform polishing can be performed.

Also, during polishing, the grindstone 10 comes into strong contact with the surface of the substrate 5 to be polished by reaction force due to friction with the substrate 5 to be polished, and separates from the substrate 5 to be polished rearward due to friction. Although it receives a force, as described above, a spherical seat bearing is constituted by the upper-end convex spherical surface of the holding body 13 and the lower-end concave spherical surface of the support body 16, so such a reaction force is absorbed and the surface of the grindstone 10 is absorbed. And the polished surface of the substrate 5 to be polished properly contact, and uniform polishing is possible.

In the above example, the support 13 or the support 16 constituting the spherical seat bearing 15 is made of a rigid body, but either or both of the support 13 and the support 16 are made of an elastic body. By doing so, at least the elastic body 17 can be omitted in this case.

FIGS. 5 and 6 show another example of the structure of the grinding wheel holding structure used in the substrate polishing apparatus of the present invention. FIG. 5 is a side sectional view and FIG. 6 is a schematic plan view. This substrate polishing apparatus is shown in FIG.
As shown in FIG. 4, the large diameter portion 11a of the casing 11 of the grinding wheel holding structure G shown in FIG.
It is the structure which was attached with. As shown in FIG. 6, the grindstone retainer 22 has a disk shape, and a plurality of (8 in FIG. 8) cutouts 22a into which the small diameter portion 11b of the casing 11 of the grindstone holding structure G is inserted. Then, the small-diameter portion 11b of the casing 11 of the grindstone holding structure G is inserted into the notch portion 22a, and the upper end surface of the large-diameter portion 11a is fixed to the lower surface of the grindstone retainer 22 with the screw 23.

5 and 6, the main wheel holding structure can be assembled by attaching the main wheel holding structure G to the main wheel retainer 22, and the screw 23 can be removed. Thereby, the whole grindstone holding structure G can be removed, and the assembling and maintenance of the whole grindstone holding structure become easy.

As described above, by attaching the grindstone holding structure G to the grindstone retainer 22, the grindstones 10 are annularly arranged at equal intervals. Thus, the grindstones 10 arranged at equal intervals in a ring shape are brought into contact with the polished surface of the polished substrate 5, and water is supplied to the upper surface of the polished substrate 5 from a water supply pipe or the like (not shown) so that the center of the grindstone retainer 22 is formed. The substrate 5 to be polished is polished by rotating the rotation shaft 24 provided in the substrate.

In the substrate polishing apparatus using the grindstone holding structure having the structure shown in FIGS. 5 and 6, the amount of polishing of the substrate 5 to be polished or the height of the grindstone 10 is measured, and the height of each grindstone holding structure G is adjusted. By rotating the knob 20, the polishing surfaces of the respective grindstones 10 can be aligned.

FIG. 7 is a side sectional view showing another example of the structure of the grindstone holding structure used in the substrate polishing apparatus of the present invention. The difference between the grindstone holding structure of FIG. 7 and the grindstone holding structure of FIG. 5 is that the large diameter portion 11a of the casing 11 of the grindstone holding structure G has a spring 2.
5 is to be attached to the grindstone retainer 22 with the screw 23 with the intermediary 5. By attaching the grindstone holding structure G to the grindstone retainer 22 with the spring 25 interposed in this way, the vertical force applied to the grindstone holding structure G is absorbed by the spring 25, and the surface of the grindstone 10 is polished. It is possible to more smoothly follow the polished surface of the substrate 5 and move.

FIG. 8 is a side sectional view showing another example of the structure of the grinding wheel holding structure used in the substrate polishing apparatus of the present invention. The present grindstone holding structure is similar to the case of FIGS. 5 to 7 in that the grindstone holding structure G shown in FIG. 4 is attached to the grindstone retainer 22, but the grindstone retainer 22 also has a rotating shaft 26 via a spherical seat bearing 29. And the connecting structure between the grinding wheel retainer 22 and the rotary shaft 26 is
6 in that the flange 26a provided on the wheel 6 is connected to the grindstone retainer 22 by screws 27 with a spring 28 interposed.

Since the grindstone retainer 22 is supported on the rotary shaft 26 via the spherical bearing 29 as described above, the whole grindstone retainer 22 can be tilted about the spherical bearing 29. Even if a reaction force is generated due to friction between the grinding wheel 10 and the substrate 5 to be polished, the reaction force applied to the entire grindstone holding structure can be absorbed by the tilting of the grindstone retainer 22 about the spherical bearing 29, and the grinding wheel 10 The reaction force due to friction with the substrate 5 to be polished
The force in which the front side in the traveling direction strongly touches the substrate 5 to be polished and the rear side in the traveling direction tends to separate from the substrate 5 is the spherical surface of the contact portion between the support 16 and the support 13 of the individual grindstone holding structure G. Since the surface is absorbed by the seat bearing 15, all the surfaces of the grindstones 10 properly contact the polished surface of the substrate to be polished, and uniform polishing can be performed.

FIG. 9 is an external view showing a configuration example of a substrate polishing apparatus according to the present invention. As shown in FIG.
An L-shaped arm 101 is fixed to a base 100.
A grindstone holding structure 104 having the configuration shown in FIG. 8 is attached to the tip of the mold arm 101 so that its rotating shaft 26 rotates in the direction shown by the arrow F by a rotating mechanism (not shown). Further, a table 102 on the base 100 is provided so as to be movable in the arrow X direction. Table 1
A substrate 5 to be polished is mounted on the substrate 02 so as to rotate in the direction of arrow E by a rotating mechanism (not shown). Also,
A leg 103 whose height can be adjusted is provided on the lower surface of the base 100.

In the substrate polishing apparatus having the above structure, water is supplied from a water supply pipe (not shown) onto the substrate 5 to be polished, and the rotating shaft 26 is rotated in the direction of arrow F and the substrate 5 is rotated in the direction of arrow E. By bringing the surface of the grindstone 10 of the grindstone holding structure 104 into contact with the substrate 5 to be polished, the substrate 5 to be polished is polished. In addition, the polishing amount of the substrate 5 to be polished or the height of the grindstone 10 is measured, and the height adjustment knob 20 is rotated to align the polished surfaces of the respective grindstones 10.

In the above substrate polishing apparatus, the grindstone holding structure 104 is the grindstone holding structure shown in FIG.
However, the present invention is not limited to this, and it goes without saying that a grindstone holding structure having the configuration shown in FIGS. 1, 2, 3, 4, 5, 6, and 7 may be used.

[0038]

As described above, according to the invention described in each claim of the present application, the following excellent effects can be expected.

According to the first aspect of the present invention, the grindstone is supported by the support via the elastic body. Therefore, even if the polished surface of the substrate to be polished has a warp or the like, the grindstone surface is kept on the polished surface. The polished surface of the substrate to be polished can be uniformly polished.

According to the second aspect of the present invention, since the grinding wheel is supported by the support via the spherical seat bearing,
Prevents the grindstone from tilting due to the reaction force caused by the friction between the grindstone and the substrate to be polished, and the grindstone surface properly contacts the polishing surface of the polished substrate,
The polished surface of the substrate to be polished can be uniformly polished.

According to the third aspect of the present invention, the grindstone comprises a large number of pellet-shaped grindstones arranged in a ring, and each of the pellet-shaped grindstones is supported by a support through a spherical bearing. As a result, the inclination of the grindstone due to the reaction force caused by the friction between the grindstone and the substrate to be polished is prevented, and each grindstone surface appropriately contacts the polished surface of the polished substrate to uniformly polish the polished surface of the polished substrate. be able to.

According to the fourth aspect of the present invention, the opposite side of the grinding wheel of the spherical seat bearing is supported by the support through an elastic body. In addition to the effect, even if the polished surface of the substrate to be polished has a warp or the like, the grindstone surface can smoothly follow the polished surface and move, and the polished surface of the polished substrate can be uniformly polished.

According to the fifth aspect of the present invention, the grinding wheel side of the spherical seat bearing is supported by the support through the elastic body. In addition, the lateral force applied to the grindstone can be absorbed, and the polished surface of the substrate to be polished can be uniformly polished.

According to the sixth aspect of the present invention, the constituent members including the grindstone and the support are combined as a grindstone holding structure, and the whole grindstone holding structure can be attached to and detached from the grindstone retainer. The replacement of the grindstone is easy, and the maintenance of the polishing apparatus is easy.

[Brief description of the drawings]

FIG. 1 is a view showing a configuration example of a grindstone holding structure used in a substrate polishing apparatus according to the present invention. FIG. 1 (a) is a side sectional view, and FIG. 1 (b).
Is a bottom view.

FIG. 2 is a view showing another configuration example of a grindstone holding structure used in the substrate polishing apparatus of the present invention. FIG. 2 (a) is a side sectional view, and FIG.
(B) is a bottom view.

FIG. 3 is a side sectional view showing another example of the configuration of the grindstone holding structure used in the substrate polishing apparatus of the present invention.

FIG. 4 is a side sectional view showing another configuration example of the grindstone holding structure used in the substrate polishing apparatus of the present invention.

FIG. 5 is a side sectional view showing another configuration example of the grinding wheel holding structure used in the substrate polishing apparatus of the present invention.

FIG. 6 is a schematic plan view showing another configuration example of the grinding wheel holding structure used in the substrate polishing apparatus of the present invention.

FIG. 7 is a side sectional view showing another configuration example of the grindstone holding structure used in the substrate polishing apparatus of the present invention.

FIG. 8 is a side sectional view showing another configuration example of the grindstone holding structure used in the substrate polishing apparatus of the present invention.

FIG. 9 is an external view illustrating a configuration example of a substrate polishing apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Whetstone 2 Support 3 Elastic body 4 Rotary shaft 5 Substrate to be polished 10 Grindstone 11 Casing 12 Elastic body 13 Holder 14 Elastic body 15 Spherical seat bearing 16 Support 17 Elastic body 18 Piston 19 Screw groove 20 Height adjustment knob 21 Dropout Prevention plate 22 Grindstone retainer 23 Screw 24 Rotary shaft 25 Spring 26 Rotary shaft 27 Screw 28 Spring 29 Spherical seat bearing

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Naosuke Matsuo 4-2-1 Motofujisawa, Fujisawa-shi, Kanagawa Inside Ebara Research Institute Co., Ltd.

Claims (6)

[Claims] 1. A substrate polishing apparatus for bringing a grinding stone into contact with a substrate to be polished and polishing the substrate to be polished by a relative motion between the substrate to be polished and the grinding stone, wherein the grinding stone is supported by a support via an elastic body. A substrate polishing apparatus, comprising: 2. A substrate polishing apparatus in which a grindstone is brought into contact with a substrate to be polished and polishes the substrate to be polished by a relative motion between the substrate to be polished and the grindstone, wherein the grindstone is supported by a support through a spherical seat bearing. A substrate polishing apparatus, comprising: 3. A substrate polishing apparatus that abuts a grindstone on a substrate to be polished and polishes the substrate to be polished by a relative motion between the substrate to be polished and the grindstone, wherein the grindstone is a large number of pellet-shaped grindstones arranged in an annular shape. Wherein each of the pellet-shaped grinding wheels is supported by a support via a spherical seat bearing. 4. The substrate polishing apparatus according to claim 2, wherein an opposite side of said grinding wheel of said spherical seat bearing is supported by a support via an elastic body. 5. The substrate polishing apparatus according to claim 2, wherein the grinding wheel side of the spherical seat bearing is supported by a support via an elastic body. 6. The substrate polishing apparatus according to claim 3, wherein the constituent members including the grindstone and the support are combined as a grindstone holding structure, and the whole grindstone holding structure is attached to a grindstone retainer. A substrate polishing apparatus configured to be detachable.