JPH1110499A - Mirror chamferring device for outer peripheral surface of disc-like semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate replacement of a polishing member by forming the polishing member like a sheet or a pad to be removably installed on the polishing surface of a polishing table. SOLUTION: Plural radial recessed grooves 24 are formed on the surface of a polishing table 4. A polishing sheet or pad 25 made by a non-woven fabric is removably fixed to the whole surface of the polishing surface by the top surface of a flange part 4a and plural small flat countersunk head screws 26 screw-inserted in the respective recessed grooves 24. As the polishing sheet 25 is removably fitted to the polishing surface of the polishing table 4 by plural small flat countersunk head screws 26, when the polishing ability is lowered due to damage of the polishing sheet 25, the sheet can be simply replaced. Further the polishing sheet 25 can be attached and detached to the recessed surface from above, so that the replacement work can be very easily conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for performing a mirror chamfering process on an outer peripheral surface of a disk-shaped semiconductor wafer.

[0002]

2. Description of the Related Art Disc-shaped semiconductor silicon wafers, even if particles on the order of microns are attached, adversely affect the production yield. Therefore, not only the surface of the wafer substrate but also the upper and lower surfaces of the outer peripheral surface. It is common that a mirror portion is also subjected to a mirror-like polishing process.

[0003] An example of a mirror chamfering apparatus for the outer peripheral surface is disclosed in, for example, JP-A-64-71657.

In this conventional apparatus, a mirror-chamfering process is performed on a polishing cloth wound on a rotary drum in such a manner that a chamfered portion of an outer peripheral surface of a disc-shaped semiconductor wafer is in vertical contact with a point. There is a problem that the processing time becomes long.

[0005] Further, if the pressure weight is increased to shorten the processing time, the wafer is thin and brittle, so that stress is concentrated on the edge of the wafer and a part of the wafer may be broken.

As a solution to such a problem, the present applicant has already filed an application for a processing method in which the processing time is short and there is no possibility of losing (Japanese Patent Application No. Hei 8 (1998) -108).
184714).

As shown in FIG. 8, a bearing 2 is suspended from a base 1, a vertical rotating shaft 3 supported by the bearing 2, and a substantially hemispherical upper surface fixed to an upper end thereof. A polishing table 4 having a concave-shaped polishing surface, a polishing pad 5 such as a non-woven fabric fixed to the surface of the polishing table 4, a belt 9 for rotating a pulley 8 fixed to the lower end of the rotating shaft 3, A driving device comprising a motor pulley 10 and a motor 11, a motor 14 provided on the right side of a support plate 12 erected on the base 1, and a horizontal which is rotated forward and reverse by this. And a movable table 16 engaged with the feed screw 15 via a slide rail 13 so as to be movable in the left-right direction.

Further, the moving table 16 is provided with a pressurizing cylinder 17, an elevating shaft 18 connected thereto, a universal joint 20 attached to the lower end thereof, and a rotary bearing 21 connected to the universal joint 20. Disk-shaped chuck 22 mounted
Are provided.

Semiconductor wafer 2 fixed to chuck 22
When performing the mirror chamfering on the outer peripheral surface of the motor 3, the motor 14 is operated to move the movable table 16 to an appropriate position, and then the pressure cylinder 17 is operated to lower the elevating shaft 18. Then, the chamfered portion of the outer peripheral surface of the semiconductor wafer 23 is brought into contact with the polishing pad 5 of the polishing table 4 with a predetermined pressing force as shown in the figure.

[0010] When the polishing table 4 is rotated in this state, the semiconductor wafer 23 is relatively rotated while being rotated, and the entire chamfered portion on the outer peripheral surface is mirror-chamfered in a short time.

At this time, the entire outer peripheral surface is substantially uniformly
As a result, a large load is not locally applied, and loss is prevented.

After the mirror chamfering on one side is completed, the wafer 23 is turned upside down and mounted on the chuck 22, and the mirror chamfering on the opposite side is performed.

[0013]

The above-mentioned conventional apparatus by the present applicant still has room for improvement, and the following points remain as problems.

That is, since the polishing pad 5 is fixed to the entire polishing surface of the polishing table 4 having a spherical shape, the replacement operation is troublesome, and the polishing table 4 is made of a relatively rigid metal or the like. Because it is necessary to form, the weight is bulky,
This may hinder movement and transportation, and increase costs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a mirror chamfering of an outer peripheral surface of a disk-shaped semiconductor wafer in which a polishing member (pad) can be easily replaced and the entire apparatus can be reduced in weight. It is intended to provide a processing device.

[0016]

In order to achieve the above object, the present invention provides an apparatus for rotating a polishing table having a concave surface on an upper surface and having a polishing member on the concave surface by a driving means. A chamfered portion on the outer periphery of the disc-shaped semiconductor wafer is pressed against the polishing member and is relatively rotated to thereby perform a mirror-chamfering process on the chamfered portion. It is characterized in that it is detachably attached to the polishing surface of the polishing table as a sheet or pad.

Preferably, the means for fixing the polishing member is a plurality of screws or resin fasteners.

It is preferable that a plurality of grooves are formed on the polishing surface, and the polishing member is fixed in the grooves by a plurality of screws or resin fasteners.

Further, the apparatus of the present invention is characterized in that a polishing table provided with a polishing member constituting a concave polishing surface on the upper surface is rotated by a driving means, and the chamfered portion on the outer periphery of the disk-shaped semiconductor wafer is rotated by the polishing means. By pressing against the member and rotating relatively,
A processing apparatus for performing a mirror-chamfering process on the chamfered portion, wherein the polishing member is a polishing body comprising a thin hard holding plate and a polishing sheet or pad fixed to the surface thereof. A polishing member is detachably attached to the polishing table.

It is preferable that the polishing body is detachably mounted on a frame-shaped polishing table.

It is preferable that the surface of the above-mentioned sheet or pad-like polishing member is made uneven.

According to the present invention, the polishing member provided on the upper surface of the polishing table has a sheet or pad shape, or a thin hard holding plate and a polishing sheet fixed to the surface thereof.
When the polishing member is detachably attached to the polishing table as a polishing body including a polishing pad or a pad, it can be easily and quickly removed and replaced when the polishing member is worn.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

The same members as those in the conventional example shown in FIG. 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIGS. 1 and 2 show a first embodiment of the present invention. As in the prior art, the polishing table 4 having a substantially hemispherical concave polishing surface on its upper surface has an outwardly facing upper end edge. A flange portion 4a is formed. Note that the concave polishing surface is not limited to a hemispherical shape, and may be a conical shape or any other shape as long as it is concave.

On the surface of the polishing table 4, a plurality (for example, four)
The groove 24 is formed so as to be directed in the radial direction, and the polishing sheet or pad 2 made of a nonwoven fabric or the like is formed on the entire polishing surface.
5 is detachably fixed by a plurality of flat head screws 26 screwed into the upper surface of the flange portion 4a and in each groove 24.

At the center of the bottom surface of the polishing table 4 and the polishing sheet 25, a liquid supply hole 27 for supplying a polishing liquid is formed, and the liquid supply hole 27 is formed to pass through the center of the rotary shaft 3. 28,
A polishing liquid is introduced from outside.

The moving table provided on the polishing table 4 includes:
The illustration of the same configuration as the conventional example is omitted.

According to the mirror chamfering apparatus of the first embodiment, since the polishing sheet 25 is detachably mounted on the polishing surface of the polishing table 4 by a plurality of flat head screws 26, the polishing sheet is removed. When the polishing ability is reduced due to wear of the plate 25 or the like, it can be easily replaced. Further, since the polishing sheet can be attached to and removed from the concave surface from above, the replacement work is extremely easy as compared with the replacement of the polishing sheet in a conventional mirror chamfering apparatus for a drum can.

Further, since a plurality of portions of the polishing sheet 25 are fixed by the countersunk screws 26 in the concave grooves 24, there is no danger that the polishing sheet 25 will be twisted in the circumferential direction during rotation. Does not interfere with the semiconductor wafer 23.

FIG. 3 shows a main part of a second embodiment of the present invention.

In this embodiment, a polishing sheet 25 is adhered to the surface of a thin holding plate 28 made of a hard synthetic resin which is previously curved to the same curvature as the polishing table 4 and has a predetermined strength. The flange 28a of the member holding plate 28 is detachably fixed to the flange 4a of the polishing table 4 by a plurality of bolts 29.

Reference numeral 27 denotes a polishing liquid supply hole similar to that of the first embodiment.

Also in the second embodiment, the polishing sheet 2
5 and the holding plate 28 can be easily replaced as an integrated abrasive body.

The polishing sheet 25 is made of the hard holding plate 2.
8, there is no risk of kinking, and the work of replacing the polishing sheet 25 can be performed more quickly than in the first embodiment, which is fixed with a plurality of flat head screws 26. it can.

FIG. 4 shows a main part of a third embodiment of the present invention.

In this embodiment, most of the bottom side of the polishing table 4 is cut off to form a frame-shaped polishing table 30, and a flange 30a of the polishing table 30 is attached to a holding plate as in the second embodiment. A polishing body 31 in which a polishing sheet 25 is adhered to the surface of 28 is detachably fixed by bolts 29.

The polishing table 30 is adapted to be rotated by the rotating shaft 3 together with a rotating plate 34 fixed to the lower ends of a plurality of brackets 33 fixed to the lower surface thereof with bolts 32.

Reference numeral 35 denotes a liquid supply pipe 36 fitted in the liquid supply hole 27.
And a hose for supplying a polishing liquid.

According to the third embodiment, most of the hemispherical polishing table 4 is cut off to form the frame-shaped polishing table 30, so that the weight can be reduced and the movement and transportation are facilitated.

Further, since the holding plate 28 is made of a hard synthetic resin, the holding plate 28 has sufficient rigidity, and there is no possibility of being deformed when the semiconductor wafer 23 is polished.

In this embodiment, it is needless to say that the abrasive body 31 can be easily replaced.

FIG. 5 shows a polishing screen used in each of the above embodiments.
13 shows a modification of the above.

The polishing sheet 37 of this embodiment is formed in a pad shape slightly thicker than the polishing sheet 25, and is provided with a large number of projections 38 on the polished surface of the polishing sheet 25 to form an uneven surface.

When such a large number of convex portions 38 are provided, as shown in an enlarged view in FIG. 6, when the outer peripheral surface of the semiconductor wafer 23 is chamfered, the outermost peripheral end surface can be brought into contact with the convex portions 38. It becomes possible and the part is also mirror-processed at the same time, so that the unpolished residue can be eliminated.

The present invention is not limited to the above embodiment.

For example, in the first embodiment, the countersunk screw 26 is used as the fixing means of the polishing sheet 25, but a resin fastener 39 as shown in FIG. 7 may be used instead. .

That is, the bottomed locking hole 40 is provided on the polishing table 4 side.
A resin fastener 39 having a plurality of retaining pieces 39a on the outer peripheral surface is provided in the locking hole 40 in the polishing sheet 25.
By pushing through the through hole drilled in the
Can be easily attached.

When removing the polishing sheet 25, the resin fastener 39 may be strongly pulled upward by a driver or the like.

[0050]

According to the present invention, the following effects can be obtained.

(A) Since the polishing member (polishing sheet) is detachably mounted on the polishing table from above, the replacement operation can be performed very easily.

(B) According to the second aspect of the invention, when the screw is used, the polishing sheet can be firmly fixed, and when the screw is used as a resin fastener, the replacement work can be performed quickly.

(C) According to the invention of claim 3, the screw or the resin fastener is prevented from interfering with the wafer during polishing.

(D) According to the invention of claim 4, in addition to the effect of the above (a), twisting of the polishing sheet can be prevented, the weight of the polishing table can be reduced, and movement and transportation are easy. Becomes

(E) According to the fifth aspect of the present invention, the weight of the polishing table can be reduced, and movement and transportation can be facilitated.

(F) According to the invention of claim 6, since the outermost peripheral end face of the semiconductor wafer is also mirror-processed at the same time, polishing residue can be eliminated.

[0057]

[Brief description of the drawings]

FIG. 1 is a perspective view of an entire polishing table showing a first embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional front view taken along line II-II of FIG.

FIG. 3 is a longitudinal sectional front view of a main part showing a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional front view of a main part showing the third embodiment.

FIG. 5 is a perspective view showing a modified example of the polishing sheet.

6 is an enlarged sectional view of a main part showing an example of polishing a wafer by the polishing sheet of FIG. 5;

FIG. 7 is an enlarged cross-sectional view of a main part showing an example of mounting a polishing sheet with a resin fastener.

FIG. 8 is a front view of a conventional device.

[Explanation of symbols]

 Reference Signs List 1 base 2 bearing 3 rotating shaft 4 polishing table 4a flange portion 5 polishing pad 8 pulley 9 belt 10 motor pulley 11 motor 12 support plate 13 sliding rail 14 motor 15 feed screw 16 Moving table 17 Pressurizing cylinder 18 Elevating shaft 20 Universal joint 21 Rotary bearing 22 Chuck 23 Semiconductor wafer 24 Depressed groove 25 Polishing sheet 26 Countersunk screw 27 Liquid supply hole 28 Holding plate 29 Bolt 30 Frame-shaped polishing table 30a Flange 31 Polishing body 32 Bolt 33 Bracket 34 Rotating plate 35 Hoses 36 Liquid supply pipe 38 Convex part 39 Resin fastener 39a Detachable piece 40 Lock hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Tamotsu Nagahama, Nakamura, Nakamura-ku, Nagoya-shi, 30 Poval Kogyo Co., Ltd. Inside Sakae Abrasive Co., Ltd.

Claims (6)

[Claims] 1. A polishing table having a concave surface on an upper surface and a polishing member provided on the concave surface is rotated by driving means,
A processing apparatus for mirror-chamfering the chamfered portion by pressing the chamfered portion on the outer periphery of the disc-shaped semiconductor wafer against the polishing member and relatively rotating the same, wherein the polishing member is sheeted. A mirror-chamfering apparatus for an outer peripheral surface of a disc-shaped semiconductor wafer, which is detachably attached to a polishing surface of the polishing table in a pad shape. 2. The apparatus according to claim 1, wherein the means for fixing the polishing member is a plurality of screws or resin fasteners. 3. The disk-shaped semiconductor wafer outer peripheral surface according to claim 2, wherein a plurality of concave grooves are formed in the polishing surface, and the polishing member is fixed by a plurality of screws or resin fasteners in the concave grooves. Miller chamfering machine. 4. A polishing table provided with a polishing member constituting a concave polishing surface on an upper surface is rotated by a driving means, and a chamfered portion on the outer periphery of the disc-shaped semiconductor wafer is pressed against the polishing member to relatively rotate. A processing apparatus for performing a mirror chamfering process on the chamfered portion by rotating the polishing member, wherein the polishing member includes a thin hard holding plate and a polishing sheet or pad fixed to a surface of the holding plate. A mirror-chamfering apparatus for an outer peripheral surface of a disc-shaped semiconductor wafer, wherein said polishing body is detachably attached to said polishing table. 5. The apparatus according to claim 4, wherein the polishing body is removably mounted on a frame-shaped polishing table. 6. The mirror chamfering apparatus for an outer peripheral surface of a disk-shaped semiconductor wafer according to claim 1, wherein the surface of the polishing member in the form of a sheet or pad has an uneven surface.