JPH08118226A - Polishing device for notch part of wafer - Google Patents

Abstract

PURPOSE: To improve polishing efficiency of a notch polishing device and homogenity of a polishing surface by rotating a takeup reel by means of a motor, bring a new part of a tape into contact with the notch part inner surface, operating respective reels for winding and delivering, and relatively moving the tape in relation to the notch part inner surface. CONSTITUTION: A wafer is made to relatively approach a pad 31, and a part of a tape T supported to the pad 31 is brought in contact with the inner surface of the notch part. The tape T is slowly and continuously wound by a takeup reel 16 by driving a motor 13. A rotational drum 2 is normally and reversely rotated around the rotary shaft within the angle range of about 270 deg. by driving a motor 12. On the other hand, the wafer is slantingly moved being centered on the specified axis parallel to the main surface. Homogeneity of the polishing surface can therefore be maintained for a long period, and the relative speed required in polishing can be sufficiently obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a notch polishing apparatus for polishing a notch used for wafer alignment or orientation.

[0002]

2. Description of the Related Art A photolithography technique is used when forming a pattern of a semiconductor integrated circuit on a silicon single crystal wafer or a compound semiconductor wafer (hereinafter referred to as a wafer). High-level alignment and orientation of the wafer are required. For this reason, a so-called notch portion, which is formed by cutting out a part of the outer peripheral portion of the wafer in an arc shape or a V shape, is provided, and the notch portion is used for aligning and aligning the wafer.

The notch portion is formed by using, for example, a drum-shaped grindstone 70 as shown in FIG. However, since the inner surface of the formed notch portion is relatively rough, it is necessary to polish the inner surface after forming the notch portion. When the inner surface of the notch portion is rough, when the inner surface of the notch portion comes into contact with a hard positioning pin (not shown) during alignment or orientation, the particle dust is generated, This is because it may get on the surface and hinder fine processing in the photolithography process.

Therefore, conventionally, the inner surface of the notch has been polished by the outer periphery of, for example, a disc-shaped rotating buff (not shown).

[0005]

[Problems to be Solved by the Invention]

However, the inner surface of the notch portion is shown in FIG.
As shown in the plan view and the vertical sectional view of FIG. 16, the notch portion N has a complicated shape in which the central portion in the thickness direction bulges outward.

Therefore, in order to polish the inner surface of the notch portion N by the rotating buff, it is necessary to move the rotating buff so as to contact the entire surface of the notch portion, and the work is complicated and time consuming. It was difficult to polish its inner surface beautifully.

Further, when the rotary buff is used, since the same portion of the rotary buff is polished, the rotary buff wears and the uniformity of the polished surface cannot be maintained for a long time. Therefore, the rotary buff is relatively frequently used. There was a problem that I had to exchange. Further, although the buffing requires a slurry, there is a problem that the slurry etches the product (wafer) at a portion other than the polished portion.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a wafer notch portion polishing apparatus capable of efficiently polishing the inner surface of the notch portion and maintaining the uniformity of the polished surface. Has an aim.

[0010]

A polishing apparatus according to claim 1 is a polishing apparatus for polishing a notch portion of a wafer, which comprises a tape having abrasive grains carried on its surface, and the tape wound and held. And a reel for reeling out the tape, a reel for reeling up the tape reeled by the reel, a motor for rotating the reel, a reel for reeling up and a reel for reeling up. The tape support member for supporting the back surface of the tape between the tape and the abutment surface of the tape against the inner surface of the notch portion, and the tape feeding member while maintaining contact between the surface of the tape and the inner surface of the notch portion And a tape reciprocating means for operating the reel and the winding reel to reciprocate the tape relative to the inner surface of the notch. It is intended.

A polishing apparatus according to a second aspect is the polishing apparatus according to the first aspect, wherein the tape reciprocating means comprises a rotary drum, and the rotary drum is reciprocally rotatable by a motor, and the rotary drum is also rotatable. The reel for feeding and the reel for winding are installed in
The tape supporting member is provided at a position apart from the rotating drum.

[0012]

According to the above-mentioned means, the new portion of the tape can be brought into contact with the inner surface of the notch portion of the wafer by rotating the winding reel by the motor, so that the homogeneity of the polishing surface can be maintained for a long time. You can do it.

Further, the tape is moved relative to the inner surface of the notch by operating the feeding reel and the winding reel directly or by reciprocatingly rotating the rotary drum by the motor, and the relative speed required for polishing. Will be obtained sufficiently. Further, the wafer is not etched because it is not necessary to use a slurry.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A polishing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the external appearance of the polishing apparatus 1 of the embodiment. The polishing apparatus 1 hangs an intermediate portion of the tape T wound on the rotary drum 2 on a tape support member 3 existing outside the rotary drum 2, and supports the tape T hung on the tape support member 3 on a wafer. The structure is such that the wafer W supported by the apparatus 4 is pressed against the inner surface of the notch portion N to be polished.

As shown in FIG. 2, the tape T has a fixed abrasive 5c adhered to the tape base 5a via an adhesive 5b. As the tape T, although not shown in the drawing, a tape base material coated with a coating material containing fixed abrasive grains may be used.

Next, the rotary drum 2 will be described.
As shown in FIG. 3, the rotary drum 2 is composed of a tubular body 6, and a bottom plate 7 and a top plate 8 which are detachably attached to the upper and lower sides of the tubular body 6, and a partition plate provided inside the tubular body 6. The inside of the rotary drum 2 is divided into three chambers, that is, a lower chamber 11a, a middle chamber 11b, and an upper chamber 11c by 9 and 10.

The rotary drum 2 is fixed to the motor shaft 12a of the motor 12. That is, in this example,
The motor shaft 12a of the motor 12 serves as a support shaft for the rotating drum 2. Further, the motor shaft 12a of the motor 12
A motor 13 is fixedly provided in the. And
The motor shaft 13a of the motor 13 is the motor shaft 12
It extends through the bottom plate 7 of the rotary drum 2 and the partition plates 9 and 10 while penetrating a. This motor shaft 13
Reference numeral a denotes a base shaft 14 and a joint shaft 15 that is detachably connected to the base shaft 14. The base shaft 14 and the joint shaft 15 are connected in the lower chamber 11a of the rotary drum 2. The base shaft 14 and the joint shaft 15 are connected by, for example, a spline. A reel 18 for delivery is attached to the base shaft 14 of the motor shaft 13a so as to be idle. The reel 18 for paying-out is in a state where the tubular body 6 is removed from the bottom plate 7 and the joint shaft 15 is removed from the base shaft 14, and
It is attached to 4. Further, a large diameter spur gear 15a is attached to the joint shaft 15 at a portion located in the inner chamber 11b of the rotary drum 2. Furthermore, the rotary drum 2 is attached to the joint shaft 15.
The winding reel 16 is attached in a half-clutch state to the portion located in the upper chamber 11c. That is, in this embodiment, the motor shaft 13a of the motor 13 serves as a support shaft for the winding reel 16, and the motor shaft 13a (joint shaft 1
Bush 17b is attached to 5) via O-ring 17a, and winding reel 16 is attached to this bush 17b. The take-up reel 16 is the top plate 8
Is attached to the joint shaft 15 in a state of being removed from the tubular body 6.

The rotary drum 2 (specifically, the cylindrical body 6)
As shown in FIGS. 1 and 6, the peripheral wall of the lower chamber 11a
Is provided with a slit 2a and the upper chamber 11c is provided with a slit 2b. The tape T fed from the feeding reel 18 through the slit 2a is once guided to the outside of the rotary drum 2 and spirally wound, and then again passed through the slit 2b. It can be guided to the inside of the rotary drum 2 and wound around the winding reel 16.

Further, in the upper chamber 11c of the rotary drum 2,
As shown in FIGS. 3 and 4, a guide roller 19 and a speed control roller 20 are installed. Of these, speed control roller 20
Shaft (roller drive shaft) 20a penetrates through the partition plate 10 and faces the inner chamber 11b. A small-diameter spur gear 21 that meshes with the large-diameter spur gear 15a is attached to the portion facing the inner chamber 11b. Has been done. The large diameter spur gear 15a and the small diameter spur gear 2
As a result of meshing with 1, the speed control roller 20 is forcibly rotated by the motor 13.

The upper chamber 11c of the rotary drum 2 is also provided with a tape speed adjusting means 22 for controlling the moving speed of the tape T with the speed controlling roller 20. The tape speed control means 22 includes a pair of arms 23 as shown in FIGS. 4 and 5, in addition to the speed control roller 20.
24, each of which has an arm 23, 24
It is configured to be swingable around a and 24a. A seesaw plate 25 having a V-shape is attached to the tip of one arm 23, and presser rollers 26a and 26b capable of simultaneously contacting the speed control roller 20 are attached to both ends of the seesaw plate 25. On the other hand, a support roller 27 is attached to the tip of the other arm 24 to support the speed control roller 20 from the side opposite to the pressing rollers 26a and 26b. This arm 2
A pressing force adjusting device 28 for adjusting the pressing force of the tape T by the pressing rollers 26a and 26b is provided at the base ends of the rollers 3 and 24.
Is attached. The pressing force adjusting device 28 has a base end fixed to the arm 24, a bolt 28a having a tip inserted into a bolt hole 23b of the arm 23, a nut 28b screwed into the bolt 28a, the nut 28b and the arm 28b. 23 and a spring 28c interposed therebetween. And in this pressing force adjusting device 28,
By operating the nut 28b, the urging force of the spring 28c is adjusted, whereby the pressing rollers 26a, 2
The pressing force of the tape T by 6b is adjusted.

As shown in FIG. 3 and FIG. 7, the tape support member 3 has a column 30 standing upright from the rotary drum 2, and an upper end of the column 30 is made of urethane rubber or the like. The strip-shaped pad 31 made of an elastic material is used as the pressing plate 3.
It is attached so as to be sandwiched between the two.
Here, the width of the pad 31 is dimensioned to fit in the notch portion N of the wafer W. The front edge of the pad 31 is sharpened in a wedge shape when viewed from above, and the angle of its tip is approximately 90 °. Since the pad 31 has a smaller width than the depth, the pad 31 is easily bent by a lateral force as shown by a chain double-dashed line in FIG. 9.

As shown in FIG. 1, the wafer support device 4 includes a suction plate 40 that is connected to a vacuum pump (not shown) and supports the wafer W, and the suction plate 40, and thus the wafer W, in a normal angle range. A motor (not shown) for rotating the wafer W, and the wafer W supported by the suction plate 40 passing through the notch portion N or the vicinity of the notch portion N, and the wafer W.
Wafer tilting means (not shown) for tilting the wafer W about an axis parallel to the main surface of the.

Although not shown, the polishing apparatus 1 is provided with means for moving the suction plate 40 relatively toward and away from the tape T.

Next, how to use the polishing apparatus 1 thus configured will be described.

First, with the tubular body 6 removed from the bottom plate 7 and the joint shaft 15 removed from the base shaft 14, the base shaft 1
The reel 18 for feeding out is attached to 4. And the bottom plate 7
The tubular body 6 is attached to and the joint shaft 15 is connected to the base shaft 14. At this time, the tip of the tape T wound around the feeding reel 18 is pulled out from the slit 2a of the tubular body 6 in advance. Next, the top plate 8 is removed, and the winding reel 16 is attached to the joint shaft 15. And the tape T
Is wound around the outer periphery of the rotary drum 2 in a spiral shape, and then the upper chamber 11c of the rotary drum 2 is passed through the slit 2b of the cylindrical body 6.
After being guided inward and sandwiched between the guide roller 19 and the speed control roller 20 and the pressing rollers 26a and 26b, the tip of the tape T is attached to the winding reel 16. Next, the top plate 8 is attached to the cylindrical body 6. After that, an intermediate portion of the tape T which is loosely wound around the rotary drum 2 is separated from the rotary drum 2 and is hooked on the tape support member 3. Next, the motor 13 is driven to drive the tape T.
Take up the slack.

On the other hand, the wafer W is sucked by the suction plate 40 of the wafer supporting device 4, and the wafer W is rotated by a motor (not shown) so that the notch portion N of the wafer W and the pad 31 are opposed to each other. Stop rotating.

Then, the wafer W is brought relatively close to the pad 31 by means not shown, and the tape portion supported by the pad 31 is brought into contact with the inner surface of the notch portion N.
Then, the motor 13 is driven to slowly and continuously wind the tape T by the take-up reel 16, and as shown in FIG. 8, the motor 12 is driven to rotate the rotary drum 2 to rotate the rotary shaft of the rotary drum 2. Rotate forward and backward around the center in the 270 ° angle range.

On the other hand, the wafer tilting means (not shown) tilts the suction plate 40 and thus the wafer W about a predetermined axis parallel to the main surface thereof. Further, the suction plate 40 and hence the wafer W are rotated in the forward and reverse directions within a small angle range by a motor (not shown).

In this way, the entire inner surface of the notch portion N of the wafer W is polished.

According to the above embodiment, the following effects can be obtained.

According to the polishing apparatus 1 of the embodiment, the motor 13
Thus, by rotating the winding reel 16, the new portion of the tape T can be brought into contact with the inner surface of the notch portion N of the wafer W, so that the homogeneity of the polishing surface can be maintained for a long time.

Further, by reciprocally rotating the rotary drum 2 on which the feeding reel 18 and the winding reel 16 are installed, the tape T moves relatively to the inner surface of the notch portion N, and the tape T moves relative to the inner surface. You will get enough speed.

Further, since the pad 31 is made of an elastic material, the tape T can be firmly brought into contact with the inner surface of the notch portion N.

Since it is not necessary to use a slurry,
The wafer is not etched either.

FIG. 10 is an external perspective view of the main part of the polishing apparatus of the second embodiment, and FIG. 11 is a vertical sectional view of the main part. Since this polishing apparatus 1 has substantially the same configuration as the polishing apparatus 1 of the first embodiment, the same reference numerals are used for corresponding parts or corresponding parts, and
Detailed description is omitted.

In this polishing apparatus 1, the rotary drum 2 is composed of a cylinder 20 having a bottom plate 7 and a top plate 8 for closing the opening of the cylinder 20. Of these, the bottom of the bottom plate 7 of the tubular body 20 is fixed to the motor shaft 12 a of the motor 12. Further, on the lower side of the bottom plate 7, another motor 1
3, the motor shaft 13a of the motor 13 penetrates the bottom plate 7 of the tubular body 20 and the tubular body 2 as shown in FIG.
It extends to the inside of 0. And this motor shaft 13
The winding reel 1 is located at a portion of the a that faces the inside of the tubular body 20.
6 is fixed. In addition, on the bottom plate 7 of the tubular body 20,
A shaft 51 is erected, and the reel 51 for feeding is attached to the shaft 51.
Can be set.

As shown in FIGS. 10 and 12, a tape slit 50 cut in the height direction of the tubular body 20 is formed on the outer peripheral portion of the tubular body 20. The tape T can be led out and introduced from the tape slit 50.

In the polishing apparatus 1, the tape T delivered from the delivery reel 18 is passed through the tape slit 50 and wound around the outer peripheral surface of the rotary drum 2 almost once along the circumferential direction. Tape support member 3 on the way
After it is hung on the pad 31 attached to the tape, it is passed through the tape slit 50 again and wound up by the winding reel 16. Further, in FIGS. 10 and 12, reference numeral 52a is a tension roller, and 52b is a pressing roller.

Although not shown, the structure of the wafer supporting device (not shown) is the same as the structure of the wafer supporting device of the first embodiment. It is also the same as the first embodiment in that it is provided with a means for moving the tape T relatively closer to and away from the tape T.

Further, in this embodiment, although not shown, means for vertically moving the rotary drum 2 and the tape support member 3 relative to the wafer W is provided. Then, for example, by moving the rotary drum 2 and the tape support member 3 relative to the wafer W during polishing, as shown in FIG. 13, the contact portion with the inner surface of the notch portion N of the tape T is moved. After the tape T is moved and the one surface of the tape T is used up, the tape T is taken up by the take-up reel 16 to expose a new surface of the tape T, and the rotary drum 2 and the tape support member 3 are lowered relative to the wafer W. It is moved to return to the initial state and similarly polished.

According to this second embodiment, the same effect as in the first embodiment can be obtained. However, according to the second embodiment, the feeding reel 18 and the winding reel 16 can be attached and detached in the first embodiment. This is easier than the polishing apparatus 1 described above.

Although the embodiment made by the present inventor has been described above, the present invention is not limited to the embodiment and various modifications can be made without departing from the scope of the invention.

For example, in the first embodiment, the tape support member 3 cannot move vertically with respect to the wafer W. However, in order to facilitate the movement of the tape T, the support of the tape support member 3 is supported. The structure may be such that 30 moves up and down relatively with respect to the wafer W as the tape T moves. Otherwise, in order to facilitate the movement of the tape T, the upper portion of the column 30 may be swingable back and forth with respect to the wafer W.

[0045]

Industrial Applicability The present invention is a polishing apparatus for polishing a notch portion of a wafer, which comprises a tape having abrasive grains carried on the surface thereof, and a reel for feeding out the tape which is held by being wound. A take-up reel for winding the tape taken out by the take-up reel, a motor for rotating the take-up reel, and a back surface of the tape supported between the take-up reel and the take-up reel. And a tape supporting member for bringing the surface of the tape into contact with the inner surface of the notch, and the reel for reeling and the reel for winding while operating the contact between the surface of the tape and the inner surface of the notch. Since the tape reciprocating means for reciprocating the tape relative to the inner surface of the notch portion is provided, the inner surface of the notch portion can be efficiently polished, It can be maintained for a long time the homogeneity of the duck polished surface. Also, since it is not necessary to use slurry, the wafer is not etched.

[Brief description of drawings]

FIG. 1 is a perspective view of a polishing apparatus according to a first embodiment.

FIG. 2 is a vertical cross-sectional view of tapes according to the first and second embodiments.

FIG. 3 is a vertical sectional view of the rotary drum of the first embodiment.

FIG. 4 is a plan view of the rotary drum of the first embodiment with a top plate removed.

FIG. 5 is a perspective view of the pressing device according to the first embodiment.

FIG. 6 is a cross-sectional view of the rotary drum of the first embodiment.

FIG. 7 is a perspective view showing a part of the tape support member according to the first and second embodiments.

FIG. 8 is a plan view showing a wound state of the tape of the first embodiment.

FIG. 9 is a plan view showing a state in which the tapes of the first embodiment and the second embodiment are in contact with the notch portion.

FIG. 10 is a perspective view of a rotary drum and its periphery according to a second embodiment.

FIG. 11 is a vertical cross-sectional view of a rotary drum and its periphery according to a second embodiment.

FIG. 12 is a plan view of a rotary drum and its periphery excluding a top plate of a second embodiment.

FIG. 13 is a diagram showing how to use the tape of the second embodiment.

FIG. 14 is a perspective view of a drum-shaped grindstone used for forming a notch portion.

FIG. 15 is a plan view showing a state in which a notch portion is formed by the hourglass grindstone of FIG.

16 is a vertical cross-sectional view showing a state in which a notch portion is formed by the hourglass-shaped grindstone of FIG.

[Explanation of symbols]

 1 Polishing Device 2 Rotating Drum 3 Tape Support Member 12, 13 Motor 16 Winding Reel 18 Feeding Reel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taiji Kuroda Ohira 150, Odakura, Nishigora-mura, Nishishirakawa-gun, Fukushima Prefecture Shirakawa Laboratory, Shin-Etsu Semiconductor Co., Ltd. (72) Toshihiro Tsuchiya Odakura, Nishigo-mura, Nishishirakawa-gun, Fukushima Prefecture Ohira 150 Address Shin-Etsu Semiconductor Co., Ltd.Shirakawa Research Laboratories (72) Inventor Koichiro Ichikawa 1650 Kiyono Matsushiro-cho, Nagano City, Nagano Prefecture In-house Fujikoshi Machinery Co., Ltd. (72) 1650 Kiyono Matsushiro-cho, Nagano City, Nagano Prefecture Fujikoshi Machine Industry Co., Ltd.

Claims (2)

[Claims] 1. A polishing device for polishing a notch portion of a wafer, comprising: a tape having abrasive grains carried on its surface; a reel for reeling out the tape and reeling out the tape; Of the tape by winding the tape reeled out by the reel for winding, a motor for rotating the reel for reeling, and supporting the back surface of the tape between the reel for reeling out and the reel for winding. A tape support member for contacting the surface with the inner surface of the notch portion, and the tape for operating the feeding reel and the winding reel while maintaining contact between the surface of the tape and the inner surface of the notch portion. And a tape reciprocating means for reciprocally moving the notch relative to the inner surface of the notch. 2. The tape reciprocating means is composed of a rotating drum, and the rotating drum can be reciprocally rotated by a motor, and the feeding reel and the winding reel are installed on the rotating drum. 2. The wafer notch polishing apparatus according to claim 1, wherein the tape support member is provided at a position apart from the rotary drum.