JPH1142553A - Wafer polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high efficiency of polishing work at a high speed of polishing, concurrently attain miniaturization of a device total unit, also facilitate mounting/demounting of a wafer in a structure, improve workability, in a wafer polishing device. SOLUTION: This wafer polishing device comprises a wafer conveyer unit 20 conveying a wafer 1 linearly in a horizontal direction and a roll member unit 30 having a roll member 301 arranged able to rotate on a conveying route of the wafer 1 to come into press contact relating to its surface to be wound with a polishing cloth 301c to a surface, and the roll member 301 winding the polishing cloth 301c is brought into press contact with a surface of the wafer l by a fixed pressure, and the wafer is polished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wafer polishing apparatus for polishing a semiconductor wafer surface with high precision.

[0002]

2. Description of the Related Art Conventionally, in a polishing apparatus of this kind, a polishing pad 42 is attached to a large rotating flat plate 41 as shown in FIG. A plurality of wafers 44 are mounted on the lower surfaces of a plurality of carrier disks 43 arranged opposite to the rotating flat disk 41, and each carrier disk 43 is pressed against the polishing pad 42 by a weight 45 or other means. Then, the polishing pad 42 and the wafer 44
The wafer 44 is polished by rotating the rotary flat plate 41 and rotating each carrier disk 43 while supplying the polishing liquid between the wafers 44 and.

[0003]

However, in the conventional wafer polishing apparatus, the outer diameter of the rotating flat plate is usually 600 mm.
It is difficult to increase the rotation speed of the rotating flat plate from such a size, and the peripheral speed must be reduced to about 100 rotations per minute. For this reason, the polishing rate was low, and high efficiency could not be expected. Further, since the size of the rotary flat plate has increased the size of the entire apparatus, reduction in the size of the apparatus has been demanded. Further, since the wafer is mounted on the lower surface of the carrier disk, it is not easy to attach and detach the wafer, leaving a problem in workability.

The present invention has been made to solve such a conventional problem. In a wafer polishing apparatus, it is possible to realize a high-efficiency polishing operation at a high polishing rate, and to downsize the entire apparatus. Another object of the present invention is to improve the workability by facilitating the attachment and detachment of a wafer in terms of structure.

[0005]

In order to achieve the above object, in a wafer polishing apparatus according to the present invention, a wafer is transported linearly in a horizontal direction, and a polishing cloth rotating on a wafer transport path is wound. The roll member is pressed against the wafer surface with a constant pressing force.

Accordingly, it is possible to realize a highly efficient polishing operation by rotating the roll member at a high speed. At the same time, the size of the entire apparatus can be reduced, and the attachment / detachment of the wafer can be facilitated structurally to improve the workability.

[0007]

DETAILED DESCRIPTION OF THE INVENTION A wafer polishing apparatus according to a first aspect of the present invention comprises a wafer transfer means for holding a wafer and transferring the wafer in a horizontal direction, and a wafer polishing apparatus rotatably disposed on a transfer path of the wafer. And a roll member having a polishing cloth attached to the surface, the roll member being pressed against the surface.

According to the above configuration, the wafer surface can be polished at high speed by the polishing cloth attached to the roll member by the high-speed rotation of the roll member. In addition, it is possible to cope with downsizing of the entire apparatus. Further, structurally, the wafer only needs to be placed on the transfer means, and the attachment / detachment operation can be easily performed.

According to a second aspect of the present invention, in the wafer polishing apparatus according to the first aspect, the roll member is rotationally driven within a range of 10 to 600 rotations per minute.

According to a third aspect of the present invention, in the wafer polishing apparatus according to the first or second aspect, the rotational speed of the roll member is set to a high speed at the outer periphery with respect to the surface of the wafer, a low speed at the center portion, and a rotational speed from the outer periphery. The speed is set gradually lower toward the center and gradually higher from the center toward the outer periphery.

According to a fourth aspect of the present invention, in the wafer polishing apparatus according to any one of the first to third aspects, the wafer transfer speed is set in a range of 10 to 100 mm per minute.

According to a fifth aspect of the present invention, there is provided a wafer polishing apparatus according to any one of the first to fourth aspects, further comprising means for pressing the roll member against the wafer surface with a constant pressing force.

According to a sixth aspect of the present invention, in the wafer polishing apparatus according to the fifth aspect, the pressing force of the roll member on the wafer surface is low at the outer periphery, high at the center, and toward the center from the outer periphery. The pressure is set to be gradually higher and gradually lower from the center to the outer periphery.

According to a seventh aspect of the present invention, there is provided a wafer polishing apparatus according to any one of the first to sixth aspects, further comprising a taper portion having a gradually decreasing diameter toward both ends of the roll member. A pair of bearings having an opening through which the roll member can be inserted, a sleeve rotatably disposed on each bearing via a bearing, and a sleeve which can be fixed to each tapered portion of the roll member, and a support disposed between the pair of bearings. A guide shaft that is inserted through the axis of the roll member and guides the roll member in the axial direction.

In a wafer polishing apparatus according to an eighth aspect of the present invention, in the configuration of any one of the first to seventh aspects, a flat plate-shaped dress board for adjusting a polishing pad is provided on the transfer table.

[0016]

FIG. 1 shows an entire configuration of an embodiment of the present invention.
2 and 3 show the configuration of each unit. In FIG.
Reference numeral 10 denotes a base, on which a wafer transfer unit 20 for transferring the wafer 1 linearly in a horizontal direction on a horizontal plane;
And a roll member unit 30 for polishing the surface of the wafer 1 to be transferred. The base 10 will be described below.
The long side direction is called a vertical direction, and the short side direction is called a horizontal direction.

The wafer transfer unit 20 is arranged on a horizontal plane of the base 10 so as to be able to swing laterally by an oscillation mechanism 201, and is arranged on the swing table 202 so as to be able to reciprocate. And a transfer table 205 for transferring the wafer 1 vertically on the horizontal plane of the base 10.

Here, the swing base 202 is made of a plate material that is long in the vertical direction of the base 10 and is installed via a plurality of rail members 203 laid horizontally on the horizontal plane of the base 10. A known oscillation mechanism 201 is configured therein. A pair of rails 204 is laid on the upper surface of the swing table 202 along the longitudinal direction.

The transfer table 205 is made of a substantially rectangular plate.
The plane is formed in a stepped shape, and a high step portion 206 is set on the front side in the traveling direction of the transfer table 205, and the chuck portion 207 of the wafer 1 is provided there. This chuck portion 207
, A vacuum chuck by vacuum suction or a suction pad is used. Further, a low step portion 208 is set on the rear side, and a flat dress board 209 for adjusting the polishing pad is provided there. Here, as shown in FIG. 2, the dress board 209 is one in which diamond is electrodeposited on the upper surface of the substrate, and is used for dressing the surface of the polishing cloth 301C wound around the peripheral surface of the roll member 301 described later. Carrier 2
05 also has sliders 210 provided on both sides of the lower surface thereof. The swing table 202 is moved through the slider 210.
It is slidably mounted on a pair of upper rails 204. In this manner, the transfer table 205 is arranged to be able to reciprocate on the swing table 202. Here, the transfer table 20
5 is driven to travel by a ball screw type driving unit 211. The traveling speed, that is, the transfer speed of the wafer 1 is set in a range of 10 to 100 mm per minute.

The roll member unit 30 is assembled in the machine frame 11 mounted on the base 10 so as to be able to move up and down.
The roll member 301 is rotatably disposed on the transfer path of the wafer 1. The lifting and lowering of the roll member unit 30 is performed by the air cylinder 12, and the roll member unit 30 is brought into pressure contact with the surface of the wafer 1 to be transferred with a constant low pressing force. Here, the machine frame 11 is raised on the base 10 in a U-shape surrounding one end of the swing table 202, that is, an end corresponding to the front side in the traveling direction of the transfer table 205. Have been. The roll member unit 30 includes a roll member 301 around which an abrasive cloth 301C is wound, a roll member support portion 305 that pivotally supports both sides of the roll member 301, and a drive portion 310 that drives the roll member 301 to rotate.

As shown in FIG. 3, the roll member 301
It has a cylindrical portion 302 and a tapered portion 303 with a gradually decreasing diameter toward the tip on each side thereof, and a screw hole 304 for a screw shaft is provided on the axis thereof. The polishing cloth 301C is spirally wound around the peripheral surface of the cylindrical portion 302 of the roll member 301. The roll member support 305 is
A pair of bearings 306 each having an opening 306L through which the roll member 301 can be inserted, and a bearing 307 in each bearing 306
The sleeve 308 is rotatably disposed through a sleeve 308 having a tapered concave surface into which each tapered portion 303 of the roll member 301 can be fitted. A guide screw shaft 309 that is screwed into the screw hole 304 and guides the roll member 301 in the axial direction. Thereby, the roll member 30
1 is supported between the two bearings 306 with both tapered portions 303 held by respective sleeves 308 arranged on a pair of bearings 306 via bearings 307. When the roll member 301 is screwed into the screw hole 304 on the axis thereof and the screw shaft 309 having one sleeve 308L inserted therein is screwed in, and when the roll member 301 is removed, the other sleeve 308R on one side is put together with the bearing 307 together with the bearing 307. By removing the screw member 309 from the bearing 306 and rotating the screw shaft 309 relative to the roll member 301 in the extracting direction, the roll member 301 is displaced in a direction to pass over the screw shaft 309 and is extracted through the opened bearing 306. Thus, the replacement of the roll member 301 can be easily performed.

The drive unit 310 of the roll member unit 30 uses a servomotor 310M, and one side of the sleeve 308L is operatively connected to the servomotor 310M so that the roll member 301 is driven to rotate. Here, the roll member 301 is moved 10 to 6 times per minute.
It is driven to rotate at high speed within the range of 00 rotations. Further, the rotation speed is set to a high speed at the outer circumference, a low speed at the center, a gradually low speed from the outer circumference to the center, and a gradually higher speed from the center to the outer circumference with respect to the surface of the wafer 1 to be transferred.

Next, the operation of the above embodiment will be described.
In FIG. 1, first, the chuck unit 207 of the transfer table 205 is used.
Is placed and chucked. When the drive unit 211 of the ball screw system is started, the transfer table 205 is moved to the swing table 2.
02 is moved in the vertical direction of the base 10 by traveling on the pair of rails 204, and is also swung in the horizontal direction of the base 10 by the oscillation function of the swing base 202. Here, the transfer speed of the wafer 1 is 10 to 1 per minute.
It is set in the range of 00 mm. On the other hand, in the roll member unit 30, it is lowered to a predetermined height position by the air cylinder 12, and the roll member 301 is driven to rotate at a high speed within a range of 10 to 600 rotations per minute.

The roll member 301 is pressed against the surface of the wafer 1 to be conveyed with a predetermined low pressure, and is polished with a polishing cloth 301C while a polishing liquid (not shown) is supplied. Here, the roll member 301 is pressed against the outer surface of the wafer 1 at a high speed rotation, and is gradually pressed from the outer periphery toward the center at a low speed, and is uniformly polished from the outer surface to the center of the surface of the wafer 1. I do. Subsequently, pressure contact is performed at a central portion at a low speed rotation, and pressure contact is gradually performed at a high speed from the central portion toward the outer periphery, so that the wafer 1 is uniformly polished from the central portion to the outer periphery. Thus, the surface of the wafer 1 is polished with high precision.

In this polishing process, the polishing cloth 3
When 01C is clogged, the rotating roll member 301 is pressed against the dress board 209 on the rear side of the transfer table 205 by traveling of the transfer table 205, and the polishing cloth 301C is dressed. In this way, the polishing cloth 301
Adjustment of C is performed.

As described above, according to the above embodiment, the polishing cloth 301C is wound around the roll member 301 and the surface of the wafer 1 is polished by the rotation thereof. Can significantly increase the polishing rate for the polishing. Further, by adopting such a roll system, each part of the apparatus can be accommodated within approximately 1 meter square, and it is possible to cope with downsizing of the entire apparatus. Further, since the wafer 1 is merely placed on the chuck portion 207 of the transfer table 205, the wafer 1 can be easily attached and detached. Furthermore, the replacement of the roll member 301 can be easily performed, which is advantageous for maintenance.

In the above embodiment, the pressing force of the roll member 301 on the surface of the wafer 1 is further reduced with respect to the surface of the wafer 1 to be conveyed, at a low pressure at the outer periphery, a high pressure at the center, and a gradually higher pressure from the outer periphery to the center. By setting the pressure gradually lower from the center to the outer periphery and pressing the roll member 301, the surface of the wafer 1 can be polished more uniformly and more precisely.

[0028]

As is apparent from the above embodiment, the present invention conveys a wafer linearly in a horizontal direction, and a roll member on which a polishing cloth rotating on a wafer conveyance path is wound on a surface of the wafer. Since the pressure is applied by the pressing force, the polishing speed can be increased by the high-speed rotation of the roll member, and the efficiency of the polishing operation can be increased.
Further, with such a wafer polishing structure, it is possible to reduce the size of the entire apparatus, and furthermore, it is possible to easily attach and detach the wafer and to improve workability.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a wafer polishing apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a carrier and a dress board used in the polishing apparatus.

FIG. 3 is a partial cross-sectional front view of a roll member unit used in the polishing apparatus.

FIG. 4 is a front view of a conventional wafer polishing apparatus.

[Explanation of symbols]

 Reference Signs List 1 wafer 10 base 11 machine frame 12 air cylinder 20 wafer transfer unit 201 oscillation mechanism 202 swing table 203 rail member 204 pair of rails 205 transfer table 206 high step section 207 chuck section 208 low step section 209 dress board 210 slider 211 Ball screw drive unit 30 Roll member unit 301 Roll member 301C Polishing cloth 302 Cylindrical part 303 Tapered part 304 Screw hole 305 Roll member support part 306 Bearing 306L Opening 307 Bearing 308 Sleeve 308L One side one sleeve 308R One side other sleeve 309 Screw Shaft (guide shaft) 310 Drive unit 310M Servo motor

Claims (8)

[Claims] 1. A wafer transfer means for holding a wafer and transferring the wafer in a horizontal direction, and a roll rotatably disposed on a transfer path of the wafer and pressed against the surface of the wafer and having a polishing cloth attached to the surface. And a member for polishing the wafer. 2. The method according to claim 1, wherein the roll member is rotated at a rate of 10 to 600 per minute.
2. The wafer polishing apparatus according to claim 1, wherein the wafer polishing apparatus is driven to rotate within a rotation range. 3. The rotation speed of the roll member is set to a high speed at the outer periphery, a low speed at the center, a gradually lower speed from the outer periphery to the center, and a gradually higher speed from the center to the outer periphery with respect to the wafer surface. 3. The wafer polishing apparatus according to claim 1, wherein 4. A wafer transfer speed of 10 to 10 minutes per minute.
4. The wafer polishing apparatus according to claim 1, wherein the wafer polishing apparatus is set in a range of 100 mm. 5. The wafer polishing apparatus according to claim 1, further comprising means for pressing the roll member against the wafer surface with a constant pressing force. 6. A pressure applied to the wafer surface of the roll member is set to a low pressure at the outer periphery, a high pressure at the center, a gradually higher pressure from the outer periphery to the center, and a gradually lower pressure from the center to the outer periphery. Item 6. A wafer polishing apparatus according to Item 5. 7. A pair of bearings each having a taper portion having a gradually decreasing diameter toward the tip at both ends of a roll member, and a pair of bearings having an opening through which the roll member can be inserted in support means for the roll member; Is arranged rotatably,
The sleeve according to claim 1, further comprising: a sleeve that can be fixed to each tapered portion of the roll member, and a guide shaft that is disposed between the pair of bearings and that is inserted through an axis of the roll member to guide the roll member in the axial direction. 7. The wafer polishing apparatus according to any one of 6. 8. The wafer polishing apparatus according to claim 1, wherein a flat dress board for adjusting the polishing cloth is provided on the transfer table.