JP2782404B2 - Swing type polishing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillating polishing apparatus for polishing a wafer such as a silicon semiconductor.

[0002]

2. Description of the Related Art Conventionally, in order to perform a polishing process on a wafer, a wafer (work) is usually placed on a lower surface of a top ring.
Is held, the wafer is pressed by a top ring on a rotating platen on which a polishing cloth is stuck on a polishing surface, and the rotating platen and the top ring are rotated while supplying slurry to the rotating platen surface. .

[0003]

According to the above-mentioned polishing process, the position of the top ring and the center of rotation of the rotary platen are always constant. Irregularities occur on the polished surface of the wafer, and the processing accuracy is reduced. In addition, the polishing cloth of the rotary platen may be unevenly worn only in a portion where the wafer is rubbed, and the processing defect may be further enlarged. Therefore, the work of replacing the polishing cloth has to be performed frequently.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional circumstances, and prevents uneven wear of a polishing pad of a rotary platen to improve the processing accuracy of a wafer and reduce the number of times of polishing pad replacement work. It is an object of the present invention to provide an oscillating polishing apparatus.

[0005]

Means for Solving the Problems As a means for technically solving the above-mentioned problems, the present invention is directed to a rotating platen having a polishing surface stuck on a polishing cloth while rotating a wafer by pressing a wafer with a top ring. A polishing device that slides and swings a top ring holding unit that holds the top ring, a driving source that drives the top ring holding unit, a swing table that holds the rotary platen, The invention has a drive source for driving a swing table, and the gist is to swing the top ring and the rotary platen simultaneously in directions orthogonal to each other.

[0006]

The top ring for holding the wafer and the rotating platen on which the polishing cloth is attached simultaneously swing in the direction perpendicular to each other, so that the trajectory of the wafer in contact with the polishing cloth on the rotating plate constantly changes, The uneven contact can be prevented by the average contact over almost the entire surface.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic plan view of a polishing apparatus,
Reference numeral 1 denotes a gate-shaped top ring holding portion. Lower ends of both legs 1a are slidably engaged with the guide rails 2, and a ball screw holder 3 fixed to one of the legs 1a is parallel to the guide rails 2. The top ring holding portion 1 is freely slidable and swingable along the guide rail 2 by rotating the ball screw 4 forward and reverse.

As shown in FIG. 2, two top rings 5 are juxtaposed downward on the lower surface of the horizontal beam 1b of the top ring holder 1, and each of these top rings 5 is a horizontal beam 1b. Drive motor 6 mounted on top of
And a vertical cylinder 7 so as to be axially rotatable and vertically movable.

That is, as shown in FIG. 3, the pedestal 8a of the cylindrical housing 8 is connected to the horizontal beam 1b of the top ring holder 1.
The rotary cylinder 9 is inserted into the cylindrical housing 8, and the support cylinder 10 is engaged with the rotary cylinder 9 so as to be slidable in the axial direction, and is attached to the pedestal 8a. The rotation of the drive motor 6 is transmitted to the rotating cylinder 9 via the gear train 11 to rotate the shaft together with the supporting cylinder 10. On the other hand, the vertical movement of the rod of the vertical cylinder 7 attached to the pedestal 8 a is transmitted to the support cylinder 10 via the stay 12 to move the support cylinder 10 up and down with respect to the rotary cylinder 9. The support tube 10 projects downward through the hole 1c of the horizontal beam 1b, and the top ring 5 is attached to a flange portion 10a at a lower end thereof.

As shown in FIG. 4, the top ring 5 has a suction plate 5a mounted in a floating state through an elastic member 5b at an opening at the lower end thereof, so that the wafer W can be suction-held by the suction plate 5a. .

A rotary platen 13 is rotatably held on a swing table 14 as shown in FIG. That is, a cylindrical pedestal 15 is fixed on the swinging table 14, and the bearing 16 and the surface plate
The turntable 13 is attached via the
The rotation of the drive motor 18 installed in the motor 4 is reduced by the speed reducer 19 so that the drive shaft 17a of the platen support 17 is rotated.

The swing table 14 has a guide piece 14a attached to the lower surface thereof and slidably engages with a guide rail 20. As shown in FIGS. Since it is provided in a direction perpendicular to the guide rail 2, it swings in a direction perpendicular to the moving direction of the top ring holding unit 1. Therefore, the rotating platen 13
Also swings in a direction perpendicular to the swinging direction of the top ring holder 1 together with the swinging table 14.

FIG. 6 shows an example of a swinging mechanism of the swinging table 14. A swinging cylinder 22 is attached to a key point via a fixed base 21, and the tip of a rod 22a is attached to the swinging table 14 side. The swing table 14 is swung by a swing cylinder 22 with a relatively short stroke in a direction parallel to the guide rail 20.

Reference numeral 24 denotes a work transfer device, which is a guide bar 24a formed by a horizontal cylinder (not shown) as shown in FIG.
And a vertical moving body 24c attached to the horizontal moving body and moved vertically by a vertical cylinder (not shown). A pair of receiving arms 24d are attached to the body 24c, and the receiving arms 24d take out wafers one by one from the wafer storage unit 25.

Numeral 26 designates a positioning device installed at the end opposite to the work transfer device 24. The work mounting table 26a having a slightly smaller diameter than the wafer and having a suction mechanism at the center thereof is rotatable. A plurality of cylindrical centering jigs 26b having rods which can be moved in and out are provided around the jigs 26b in a centripetal direction, and a wafer orientation flat detection sensor 26c is provided at a predetermined position below the work placement table 26a. , So that the wafer W placed on the work placing table 26a can be positioned.

In the oscillating polishing apparatus according to the present invention thus constructed, the wafer W is taken out of the wafer accommodating section 25 by the work transfer apparatus 24 and is made to stand by at a predetermined position. The top ring 5 is moved to position it directly above the wafer W of the work transfer device 24, and the top ring 5 is lowered to move the wafer W
Is adsorbed by the adsorption disk 5a, and is raised to the original position after the adsorption.

While maintaining this state, the top ring holding unit 1 is moved to the positioning device 26 to release the suction of the suction disk 5a to mount the wafer W on the work mounting table 26a. The section Wa (orientation flat section) is detected and positioned.

Thereafter, the top ring 5 is lowered again, and the wafer W is sucked by the suction disk 5a. Then, the top ring holding unit 1 is moved to position the top ring 5 on the rotary platen 13, and this rotation fixed The wafer W is pressed against the polishing cloth C stuck on the polishing surface of the board 13 with an appropriate pressure, and the wafer W is polished while supplying the slurry.

In this polishing step, the top ring 5 is rotated about the axis, and the top ring holding portion 1 can be moved in the left-right direction in FIG.
In addition, since the rotating platen 13 can be swung up and down in FIG. 1 by the swinging table 14, the wafer W comes into contact with the polishing pad C over substantially the entire surface on average. Accordingly, partial uneven wear of the polishing cloth C is prevented and the wafer W
Polishing can be performed with high precision. At this time, since there are two top rings 5, it is possible to mirror-process two wafers at one time.

[0020]

[0021]

As described above, according to the present invention,
In a polishing machine that rotates a wafer while pressing a wafer with a top ring on a rotating surface plate with a polishing cloth adhered to the polishing surface, the top ring and the rotating surface plate were simultaneously swung in directions perpendicular to each other, so that the polishing cloth The wafers are in average contact over almost the entire surface, preventing uneven wear of the polishing cloth, improving the processing accuracy of the wafer, and reducing the number of times of polishing cloth replacement work. It has the effect.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an oscillating polishing apparatus showing one embodiment of the present invention.

FIG. 2 is an explanatory view showing a mounting position of a top ring and a swing mechanism of a rotary platen.

FIG. 3 is a sectional view taken along line AA in FIG.

FIG. 4 is a cutaway view of the top ring.

FIG. 5 is a longitudinal sectional view of a rotary platen and a swing mechanism thereof.

FIG. 6 is an explanatory diagram showing an example of a drive unit of the swing mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Top ring holding part 1a ... Leg 1b ... Horizontal beam 1c ... Hole 2 ... Guide rail 3 ... Ball screw holder 4 ... Ball screw 5 ... Top ring
5a: suction disk 5b: elastic material 6: drive motor
7 Vertical cylinder 8 Cylindrical housing 8
a ... pedestal 9 ... rotating cylinder 10 ... support cylinder 10a ...
Flange part 11 ... gear train 12 ... stay 13
... Rotating surface plate 14 ... Swinging table 14a ... Guide piece 15 ... Receiving base 16 ... Bearing 17 ... Surface plate receiving 17a ... Drive shaft 18 ... Drive motor
19: reducer 20: guide rail 21: fixed base 22: swing cylinder 22a: rod 2
3 Floating joint 24 Work transfer device 24a Guide bar 24b Horizontal moving body
24c: vertical moving body 24d: receiving arm 25: wafer storage unit 26
... Positioning device 26a ... Work placement table 26b ... Centering jig 26c ... Orientation flat part detection sensor

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Inada 1650, Kiyono, Matsushiro-machi, Nagano, Nagano Prefecture Inside Fuji Machinery Co., Ltd. (72) Inventor Makoto Nakajima 1650, Kiyono, Matsushiro-cho, Nagano, Nagano Prefecture (56) References JP-A-4-210369 (JP, A) JP-A-50-77994 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B24B 37 / 04

Claims (1)

(57) [Claims] 1. A polishing apparatus for rotating a wafer while pressing a wafer with a top ring on a rotary platen having a polishing cloth adhered to a polishing surface, comprising a slide for holding the top ring and a swingable top ring holding. Unit, a drive source for driving the top ring holding unit, a swing table for holding the rotary platen, and a drive source for driving the swing table, and the top ring and the rotary platen are mutually connected. Orthogonal
An oscillating polishing apparatus characterized by simultaneously oscillating in directions .