JPH09123050A - Mirror surface polishing method of chamfering surface of semiconductor wafer and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain size reduction of a polishing device of a chamfering surface, and polish the chamfering surface with high throughput by simultaneously removing a lateral directional stripe and a longitudinal directional stripe of the chamfering surface. SOLUTION: A semiconductor wafer W is installed in a support member, and is driven in rotation by a motor. Polishing cloth of a polishing drum is pressed to and contacted with a chamfering surface of this wafer, and the chamfering surface is mechanochemically polished. A polishing liquid containing free abrasive grains is supplied to the polishing cloth. The polishing cloth performs mirror surface polishing on the chamfering surface while being viscoelastically deformed. At this time, the polishing cloth is pressed to and contacted with the chamfering surface of the wafer while rotating the longitudinal direction (the direction orthogonal to the wafer circumferential direction) X. As a result, a circumferntial directional stripe is not generated on the chamfering surface. Similarly, a stripe does not remain in the longitudinal direction. It is because a wide surface of the polishing cloth contacts with the chamfering surface. At the same time, productivity can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mirror polishing method and polishing apparatus for a chamfered surface of a semiconductor wafer, and more particularly to a drum chamfering.

[0002]

2. Description of the Related Art Conventionally, CMP (chemical mechanical) is applied to the periphery (chamfered surface) of a semiconductor wafer.
PCR (polishing)
Hed corner rounding) is known. In this PCR device, the chamfered surface of the peripheral edge of the semiconductor wafer was polished while supplying a polishing liquid using a polishing drum having a polishing cloth attached to the outer surface. The polishing drum was pressed against the chamfered surface of the silicon wafer while rotating about an axis parallel to the rotation axis of the silicon wafer.

On the other hand, a chamfering technique using a tape is also known. The chamfered surface is polished by pressing the tape, which is an inelastic body, in a direction perpendicular to the wafer surface while pressing it against the wafer peripheral edge (chamfered surface) with a predetermined pressure.

[0004]

However, in such a conventional polishing technique for a chamfered surface of a semiconductor wafer,
First, in the former case, the device itself is large. Therefore, the installation requires a large space. Also,
There was a problem that lateral (circumferential) streaks remained on the chamfered surface. On the other hand, even in the latter case, since the tape made of a non-elastic material is used, the stripes of the tape width remain along the tape running direction.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a chamfered surface polishing technique capable of removing both the horizontal and vertical streaks of the chamfered surface. Another object of the present invention is to provide a polishing apparatus for a chamfered surface of a semiconductor wafer, which has a reduced size. Further, it is an object of the present invention to provide a chamfered polishing apparatus capable of processing with high throughput.

[0006]

The invention according to claim 1 is a method for mirror-polishing a chamfered surface of a semiconductor wafer, wherein the chamfered surface of the chamfered semiconductor wafer is mechanochemically polished by using a polishing drum. This is a mirror polishing method for a chamfered surface of a semiconductor wafer by arranging a polishing drum so that its rotation axis is substantially parallel to the surface of the semiconductor wafer and rotating the polishing drum.

According to a second aspect of the present invention, there is provided a supporting means for rotatably supporting the semiconductor wafer, and a rotation axis substantially parallel to the surface of the semiconductor wafer supported by the supporting means.
A polishing device for a chamfered surface of a semiconductor wafer, comprising: a polishing drum provided so that the chamfered surface of the semiconductor wafer can be polished.

The invention according to claim 3 is the polishing apparatus for a chamfered surface of a semiconductor wafer according to claim 2, wherein a plurality of the polishing drums are provided for one supporting means.

According to a fourth aspect of the present invention, the supporting means has a pair of supporting members that move between two positions, and the polishing drum can polish a semiconductor wafer supported by the supporting members at each position. The polishing apparatus for a chamfered surface of a semiconductor wafer according to claim 2 or 3, which is provided in the above.

[0010]

According to the first aspect of the present invention, the polishing cloth of the polishing drum polishes the chamfered surface of the semiconductor wafer while rotating in the longitudinal direction (direction orthogonal to the circumferential direction). Therefore, a horizontal (circumferential) streak does not remain on the chamfered surface. At the same time, no streaks are left in the vertical direction.
This is because a polishing cloth that is an elastic body and contains loose abrasive grains is used.

In the chamfered surface polishing apparatus according to the second to fourth aspects, the chamfered surface does not have a horizontal stripe. At the same time, no vertical streaks remain. Further, the wide surface of the polishing cloth comes into contact with the chamfered surface, and the productivity can be improved. Further, the throughput can be increased by providing a plurality of supporting means on the semiconductor wafer.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views for explaining polishing of a chamfered surface by a chamfered surface polishing apparatus according to an embodiment of the present invention. As shown in these figures, in this chamfered surface polishing apparatus, support members 11 and 12 that attract a semiconductor wafer W placed horizontally and rotatably support the semiconductor wafer W are arranged at regular intervals. It is set up. These supporting members 11 and 12 have a structure in which their positions can be interchanged by rotating 180 degrees in a horizontal plane about a vertical axis 21 arranged in the middle.

The support members 11 and 12 are a pair of horizontal suction pads 11A and 12 which are vertically movable.
The semiconductor wafer W is horizontally sandwiched and fixed between the suction pads 11A and 12A with the peripheral portion (chamfered surface) thereof exposed. The upper suction pads 11A and 12A are rotatably supported by motors 211 and 212, respectively.
A and 12A are configured to rotate together when the semiconductor wafer W is held.

Two polishing drums 13 and 14 are provided on both sides of the support members 11 and 12, respectively. In the supporting member 11 at the position shown in FIGS. 2 and 3, the chamfered surface of the upper side of the semiconductor wafer W is mirror-polished (CMP) by the polishing drums 13 and 14, and the supporting member 12 is also polished by the polishing drums 13 and 14. The positions of the polishing drums 13 and 14 are set so that the chamfered surface on the lower side of the semiconductor wafer W is polished. The pair of polishing drums 13 and 14 are arranged so as to be separated from each other by substantially the wafer diameter. The arrow X in the figure indicates the polishing drums 13, 1.
4 shows the rotation direction. 22 and 23 are motors for driving these polishing drums 13 and 14.

Each of the polishing drums 13 and 14 has a predetermined diameter, and a polishing cloth 24 is fixed to the outer surface thereof (see FIG. 5), and the entire drum is elastically deformable in the radial direction. Further, the polishing drums 13 and 14 are arranged such that the rotation axes thereof are in the horizontal plane. Further, the polishing drums 13 and 14 are rotatable by motors 22 and 23 about a rotation axis at a predetermined speed, and
It is provided so that it can move up and down. Furthermore, each polishing drum 1
3 and 14 are provided so that they can move toward and away from the support members 11 and 12 as the support base 25 travels on the guide rails 26 (direction of arrow Y in FIG. 2). A polishing liquid containing a polishing agent is supplied to each polishing cloth 24, and the chamfered surface is mirror-polished while deforming as a viscoelastic body (CM.
P). This state is shown in FIG.

As described above, the semiconductor wafer W is mounted on the motor 21.
While being driven by 1, 212 and rotating at a predetermined speed,
The chamfered surface is mechanochemically polished by the polishing cloth 24 of the polishing drums 13 and 14. At this time, the polishing cloth 24 forming the cylindrical surface is pressed and brought into contact with the chamfered surface of the semiconductor wafer W while rotating in the vertical direction (direction orthogonal to the circumferential direction of the wafer) X. As a result, circumferential streaks or the like do not occur on the chamfered surface.

Further, the semiconductor wafer W mounted on the support members 11 and 12 has a chamfered surface on the upper side polished at the position on the support member 11 side, and a chamfered surface on the lower side at the position on the support member 12 side. To be polished. Since the chamfered surface is divided into the upper side and the lower side in this way, the polishing can be performed efficiently. This is because it is possible to successively and automatically carry out the steps from the loading of the semiconductor wafer W, the polishing of the upper chamfered surface / the lower chamfered surface to the discharge thereof.

Further, in this device, the V-shaped notch 30
It is particularly effective for the semiconductor wafer W having This is because, as shown in FIGS. 4 and 5, since the polishing cloth 24 is rotated in the vertical direction, the notch surface 30 which cannot be polished by the conventional polishing drum can be perfectly mirror-polished. The polishing cloth 24 is elastically deformed by a predetermined width w as shown in the figure to polish the notch surface 30. further,
In a dual (dual type) device configured in this way, an orientation flat (orientation flat)
Even the attached semiconductor wafer W can be efficiently polished. When polishing the orientation flat portion, the supporting member 1
This is because it is possible to stop the rotation of one of the support members 1 and 12 and to polish the chamfered surface of the other supporting member. In this dual type, loading and unloading of the semiconductor wafer W are simultaneously performed from one direction to shorten the time.

FIG. 6 shows another embodiment of the present invention. As shown in this embodiment, the suction plate 61 for sucking the wafer W is formed as large as possible,
May be held on one side. This makes it possible to use a large-diameter polishing drum, which is suitable for mirror-polishing a chamfered surface. Especially, it is suitable for mirror polishing having a deep notch. Wafer W with single-sided support
Since the suction plate 61 is in contact with substantially the entire surface of the above, its holding force is sufficient. Further, as shown in FIG. 7, the chamfered surface of one semiconductor wafer W is cut into four polishing drums 71, 7
It can also be configured to polish simultaneously with 2, 73 and 74. The upper chamfered surface and the lower chamfered surface of the semiconductor wafer W can be processed at the same time to improve the productivity.

Further, the chamfered surface can be polished after the conventional CCR process. As a result, a high-quality chamfered surface can be obtained in a shorter time than before.

[0021]

According to the present invention, the productivity is improved. Further, the device can be downsized. Therefore, space can be saved. Further, the notched wafer can also be subjected to PCR. Horizontal lines can be removed from the chamfered surface.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing polishing of a chamfered surface according to an embodiment of the present invention.

FIG. 2 is a front view showing a chamfered surface polishing apparatus according to an embodiment of the present invention.

FIG. 3 is a plan view showing a chamfered surface polishing apparatus according to an embodiment of the present invention.

FIG. 4 is a plan view showing chamfering of a notch portion according to an embodiment of the present invention.

FIG. 5 is a sectional view taken along the line VV of FIG. 4;

FIG. 6 is a sectional view showing polishing of a chamfered surface according to another embodiment of the present invention.

FIG. 7 is a plan view showing a chamfered surface polishing apparatus according to still another embodiment of the present invention.

[Explanation of symbols]

 11, 12 Support member, 13, 14 Polishing drum.

[Procedure amendment]

[Submission date] March 4, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

[Fig. 2]

[Figure 3]

FIG. 4

FIG. 7

[Figure 5]

FIG. 6

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Kawaguchi 985 Inouno, Gintan, Ikuno-cho, Asago-gun, Hyogo Prefecture 1 Mitsubishi Materials Corporation, Ikuno Works (72) Inventor Kenji Mune, Ikuno, Asago-gun, Hyogo Prefecture Machiguchi Gintan, Ino No. 985, Ikuno Works, Mitsubishi Materials Corporation

Claims (4)

[Claims] 1. A method of mirror-polishing a chamfered surface of a semiconductor wafer, wherein the chamfered surface of the chamfered semiconductor wafer is mechanochemically polished by using a polishing drum. A mirror polishing method for polishing a chamfered surface of a semiconductor wafer by arranging them in parallel and rotating the chamfered surface of the semiconductor wafer. 2. A support means for rotatably supporting a semiconductor wafer, and a rotation axis substantially parallel to the surface of the semiconductor wafer supported by the support means. The chamfered surface of the semiconductor wafer is provided so as to be polished. A polishing device for a chamfered surface of a semiconductor wafer, comprising a polishing drum. 3. The polishing apparatus for a chamfered surface of a semiconductor wafer according to claim 2, wherein a plurality of the polishing drums are provided for one supporting means. 4. The support means has a pair of support members that move between two positions, and the polishing drum is provided so as to be capable of polishing a semiconductor wafer supported by the support members at each position. Alternatively, the polishing apparatus for polishing a chamfered surface of a semiconductor wafer according to claim 3.