JPH04364729A - Apparatus for chamfering wafer notch - Google Patents

Abstract

PURPOSE:To enable chamfering work easily and surely to a notch, to achieve chamfering work to this notch, and to simplify a constitution. CONSTITUTION:The following are provided: a rotary disc-shaped grindstone 16; a wafer-holding mechanism 14 that holds a wafer 12; a first drive mechanism 15 rotated over a predetermined range of angles around its center axis (in the arrow theta direction); and a second drive mechanism 20 that advances and retreats the wafer 12 in the arrow X direction; and a third drive mechanism 22 that advances and retreats the grindstone 16 in the Z direction. This grindstone 16 has a substrate 52 made of an elastic material and a plurality of grind grains 54 buried in the peripheral face of the substrate 52.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer chamfering device, and more particularly to a wafer notch chamfering device using an elastic grindstone.

0002

[Prior Art] Conventionally, when applying photolithography to wafers such as semiconductor wafers, a portion of the outer periphery of the wafer is ground into a straight line in order to facilitate alignment of the wafer in an exposure device. An orientation flat (hereinafter referred to as OF) is formed.

However, in order to provide this OF, a large amount of removed portion is generated, and especially in the case of a wafer having a large diameter, this removed portion becomes a considerable area, resulting in a significant decrease in yield. This has led to the problem that expensive semiconductor wafers cannot be used efficiently.

[0004] Therefore, in order to utilize the wafer at a high yield, a notch portion having a substantially V-shape, a substantially arc-shape, or the like is formed on the outer peripheral portion of the wafer. In particular, V-shaped notches are widely used because of their superior positioning accuracy. In this case, since the wafer is transported many times on the line during the device manufacturing process, the outer periphery of the wafer may come into contact with some of the equipment used in the same manufacturing process, causing chips or chips on the outer periphery. Since this may lead to deterioration of device characteristics, chamfering has conventionally been performed on the outer periphery of the wafer.

[0005]

[Problems to be Solved by the Invention] However, conventionally, in the case of a wafer having the above-mentioned notch portion, chamfering was not required because the dimensions of the notch portion were smaller than the outer circumferential length of the wafer. In the device manufacturing process, when the notch is engaged with a hard pin to position the wafer, there is a problem in that the notch is chipped, and it is particularly difficult to remove sharp edges. As dust generation increases, the problem of not being able to prevent chips and the like has become impossible to ignore.

The present invention has been developed in view of this type of problem, and can easily and reliably chamfer even the sharp edges of notches. can be carried out efficiently,
Moreover, it is an object of the present invention to provide a wafer notch chamfering device having a simple configuration.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a rotating disk-shaped grindstone, a wafer holding mechanism that holds a wafer, and a rotating disk-shaped grindstone, a wafer holding mechanism that holds the grindstone and the wafer,
The grinding wheel is equipped with a drive mechanism for relatively moving the grinding wheel, and the grinding wheel is characterized in that it has an elastic material base material and abrasive grains embedded or dispersedly fixed therein.

[0008]

[Operation] In the wafer notch chamfering apparatus according to the present invention, the grinding wheel and the wafer move relative to each other under the action of the drive mechanism to chamfer the notch of the wafer. At that time, the base material that makes up the whetstone is made of an elastic material, and the abrasive grains are pressed against the chamfered part through its elastic force, so it is easy to prevent sharp corners from remaining in the chamfered part. can be prevented.

[0009] Since the base material of the whetstone is made of an elastic material, the cross-sectional shape of the outer peripheral end of the whetstone is approximately V-shaped with an R section at the bottom, and the angle formed by the side line of the V-shape is defined as the notch plane. If the corresponding angle of the figure and the R of the tip of the notch toward the wafer center are made slightly larger, the grinding wheel can be brought into contact with the notch with the center of rotation of the grinding wheel set at a position higher than the wafer surface position. For example, the chamfering of the notch portion can be completed by simply slightly moving the grindstone in the vertical direction. By appropriately adjusting the softness of the base material of the grinding wheel, the formation of a concave curved surface on the chamfered portion due to the grinding wheel surface can be eliminated, and rather an ideal notch chamfering with a gently curved surface protruding outward can be achieved. Become. In this case, especially among the first, second, and third drive mechanisms recited in the claims, the contact position of the grindstone is precisely controlled and adjusted before the chamfering process. It will be used for

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the wafer notch chamfering apparatus according to the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a notch chamfering device according to this embodiment. This notch chamfering device 10 includes a wafer holding mechanism 14 that holds a wafer 12 in a predetermined posture, and a wafer holding mechanism 14 that rotates the wafer 12 around a central axis perpendicular to its main surface (in the direction of arrow θ) within a predetermined angular range. a first drive mechanism 15; a rotary drive mechanism 18 for mounting a disk-shaped grindstone 16 so that its surface intersects (orthogonally in the embodiment) the surface of the wafer 12;
6 and the wafer 12 relative to each other in the radial direction of the grindstone 16 (in the direction of arrow X).
6 and the wafer 12 in the thickness direction of the wafer 12 (
and a third drive mechanism 22 provided on the rotary drive mechanism 18 for relative movement forward and backward in the direction of arrow Z).

The wafer holding mechanism 14 includes a base 28 , and a cylindrical portion 30 is provided on the base 28 .
A rotary table 32 is arranged at 0, and this rotary table 32
The wafer 1 is connected to a vacuum pump (not shown) on the upper end surface.
A plurality of suction holes 34 are formed for sucking 2. The first drive mechanism 15 includes a pulse motor 36 that is a servo motor, and a feed screw 38 is connected to the pulse motor 36, and the feed screw 38 is coaxially engaged with the rotary table 32.

The second drive mechanism 20 includes a pulse motor 40 , and a feed screw 42 connected to the rotating shaft of the pulse motor 40 engages with the wafer holding mechanism 14 . The rotational drive mechanism 18 includes an electric motor 44, and the grindstone 16 is rotatably fixed to a rotating shaft 46 of the electric motor 44. A feed screw 50 connected to a pulse motor 48 constituting the third drive mechanism 22 engages with this rotational drive mechanism 18 .

The grinding wheel 16 includes a base portion 52 made of an elastic material, for example, a synthetic resin material such as urethane rubber, and abrasive grains 54 embedded in a relatively soft peripheral surface of the base portion 52, which serves as a grinding surface. and has. Further, the grindstone 16 may be formed into a disk shape by dispersing abrasive grains in a synthetic resin base material, and the outer peripheral portion of the disk may be used for the grinding of the present invention.

Next, the operation of the notch chamfering device 10 constructed as described above will be explained. First, a disk-shaped wafer 12 is placed on a rotary table 3 that constitutes a wafer holding mechanism 14.
2, and is attracted to this rotating table 32 through a suction hole 34 under the action of a vacuum pump (not shown). and,
After the notch portion 24 of the wafer 12 and the grindstone 16 are arranged at predetermined positions with their respective surfaces orthogonal to each other, the first to third drive mechanisms 15 to 22 are selectively or synchronously driven. controlled. Therefore, under the action of the pulse motor 36, the turntable 32 is rotated at a predetermined rotational speed in the direction of arrow θ via the feed screw 38, and under the action of the pulse motor 40, the feed screw 42 is rotated to remove the wafer. The holding mechanism 14 moves forward and backward in the direction of arrow X. on the other hand,
The grindstone 16 is rotated via the rotating shaft 46 under the driving action of the electric motor 44 . Therefore, while the wafer 12 and the rotating grindstone 16 move toward or away from each other, the wafer 12 is rotated in the direction of the arrow θ.
A corner portion 12a of the notch portion 24 of the wafer 12 is partially chamfered in the length direction of the inner circumference (see FIG. 2).

While chamfering a part of the corner 24a of the notch 24 in the direction of the inner circumference, the grindstone 16 is moved at a relatively low speed in the direction of the arrow along this corner 24a, as shown in FIG. . That is, when a drive signal is derived to the pulse motor 48 constituting the third drive mechanism 22, the feed screw 50 is rotated in a predetermined direction via the pulse motor 48, and the rotation engaged with the feed screw 50 is rotated. The drive mechanism 18 moves slowly in the direction of arrow Z1. In synchronization with this, the pulse motor 40 is driven to drive the grindstone 16 and the wafer 12.
are relatively moved in the direction of arrow X1, and this grindstone 16 is positioned corresponding to the corner 24a. Therefore, as described above, after chamfering of a portion of the corner 24a in the circumferential direction is completed, chamfering of the other portion of the corner 24a in the inner circumferential length direction is continuously performed.

Next, the circumferential surface portion 24b and corner portion 24c of the wafer 12 are similarly shaped continuously a plurality of times at predetermined intervals. Here, while processing the outer peripheral surface portion 24b perpendicular to the main plane of the wafer 12, the grindstone 16 is moved in the direction of the arrow Z2, while during processing the corner portion 24c, the grindstone 16 and the wafer 12 are moved in the direction indicated by the arrow Z2. It is relatively moved in the X2 and Z3 directions. This provides the effect that chamfering in the circumferential direction and the thickness direction of the wafer 12 can be performed continuously and efficiently.

In this case, in this embodiment, since the grinding wheel 16 has a substrate portion 52 made of an elastic material, the wafer 12 is chamfered while the grinding wheel 16 is pressed against the wafer 12 with a predetermined pressing force. Can be processed. That is, as shown in FIG. 3, when the grindstone 16 is pressed against the wafer 12, the relatively soft peripheral surface of the base plate 52 forming the grindstone 16 is deformed and pressed against the wafer 12. Therefore, the abrasive grains 54 embedded in the peripheral surface are
The wafer 12 is ground by widely contacting the wafer 12, and in particular, the corners A to D (see the two-dot chain line in FIG. 4) of the surface to be ground of the wafer 12 are ground, and R is applied to the corners A to D.
(See the solid line in FIG. 4). Therefore, no chipping or chipping occurs at the corners A to D, and the corner A can be easily controlled without complicated control.
The effect that R can be easily formed on D to D can be obtained.

In particular, by arranging the surface of the wafer 12 and the surface of the grindstone 16 to be perpendicular to each other, the grinding surface of the grindstone 16 is applied to the surface to be ground of the notch portion 24, which is considerably smaller than the size of the wafer 12. The advantage is that highly accurate chamfering can be performed through the surface.

Further, in this embodiment, while chamfering the notch portion 24 in the circumferential direction, the grinding wheel 16 is placed on the wafer 1.
2 in the board thickness direction (arrow Z direction) to chamfer the entire notch part 24. However, conversely, while chamfering the notch part 24 in the board thickness direction, the grindstone 16 and The chamfering operation can be performed by moving the wafer 12 in the circumferential direction of the wafer 12.

That is, by driving and controlling the second drive mechanism 20 and the third drive mechanism 22 in synchronization, the grindstone 16 is moved in the direction of arrow Z while moving the wafer 12 in the direction of arrow X, and the notch portion is moved. A part of the wafer 24 in the thickness direction is chamfered, and the pulse motor 36 is rotated at a relatively low speed to slowly rotate the wafer 12 around its central axis (in the direction of the arrow θ). This results in
The grindstone 16 can chamfer the notch portion 24 in the thickness direction thereof while continuously chamfering the notch portion 24 in the circumferential direction.

[0022]

According to the wafer notch chamfering apparatus according to the present invention, the following effects can be obtained. When chamfering the notch portion of the wafer while the grinding wheel and the wafer move relative to each other under the action of the drive mechanism, since the substrate portion constituting the grinding wheel is formed of an elastic material, Since the abrasive grains are pressed against the chamfered portion through the elastic force, it is possible to easily prevent sharp corners from remaining in the chamfered portion. Therefore, with a simple configuration of using an elastic grindstone, it is possible to chamfer a small notch portion in the circumferential direction and/or the thickness direction with high precision and efficiency.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view of a wafer notch chamfering device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a chamfering operation in the thickness direction of a notch portion.

FIG. 3 is an explanatory diagram after the wafer is chamfered.

FIG. 4 is an explanatory diagram of a state in which the substrate portion of the grindstone is deformed by being pressed by a wafer.

[Explanation of symbols]

10 Notch chamfering device 12 Wafer 14 Wafer holding mechanism 15 Drive mechanism 16 Whetstone 18 Rotation drive mechanism 20, 22 Drive mechanism 24 Notch part 32 Turntable 36, 40, 48 pulse motor 52 Board part 54 Abrasive grain

Claims (4)

[Claims] 1. A rotating disc-shaped grindstone, a wafer holding mechanism that holds a wafer, and a rotating disc-shaped grindstone, the grindstone and the wafer comprising:
1. A device for chamfering a notch portion of a wafer, comprising a drive mechanism for relatively moving the grindstone, and the grindstone has an elastic material base material and abrasive grains embedded or dispersedly fixed therein. 2. The apparatus for chamfering a notch portion of a wafer according to claim 1, wherein the wafer holding mechanism is arranged so that the surface of the wafer intersects the surface of the grindstone. 3. The apparatus according to claim 1, wherein the drive mechanism rotates the wafer along its central axis in order to continuously position and grind the surface to be ground of the notch portion of the wafer with respect to the grinding surface of the grindstone. a first drive mechanism that is rotatable around a predetermined angular range; a second drive mechanism that moves the grindstone and the wafer relatively forward and backward in a direction toward or away from each other; A wafer notch chamfering device characterized by comprising a third drive mechanism that relatively moves the wafer forward and backward in the thickness direction of the wafer. 4. The apparatus for chamfering a notch portion of a wafer according to claim 1, wherein the base material is a synthetic resin material.