JPH045241Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a wafer chamfering device suitable for use when chamfering a disk-shaped wafer such as a silicon wafer.

[Conventional technology]

In the manufacturing process of silicon and other semiconductor wafers, there is a process of grinding the wafer's outer peripheral side surface using a grindstone and chamfering the upper and lower parts of the wafer's outer periphery.

Conventionally, a grindstone 1 as shown in FIG. 6 has been used in this chamfering process, and the vertical part 1a of this grindstone 1
The outer periphery was ground, and the upper and lower chamfers were chamfered on the inclined surfaces 1b and 1c (angle of inclination a°), respectively. That is, while rotating the wafer 2,
The relative vertical positional relationship between the wafer 2 and the grinding wheel 1 is changed to bring them into contact with the outer periphery of the wafer.
Both the outer periphery grinding and chamfering processes were performed using a single grindstone 1. However, with this type of equipment, which performs all processes using a single grindstone, one process must be completed before moving on to the next process, which takes time and reduces productivity. It was hot. Therefore, a chamfering device was developed that could perform each process overlappingly at almost the same time (Japanese Patent Application Laid-Open No.
No. 60-104644). FIG. 7 is a plan view showing the configuration of this type of chamfering device, and in the figure, 5, 6, 7,
Reference numerals 8 denote an outer circumference rough grinding wheel, an outer circumference fine grinding wheel, a grindstone exclusively for upper chamfering, and a grindstone exclusively for lower chamfering. These grinding wheels 5, 6, 7, 8 are driven by motors M1, M2, M, respectively.
3 and M4 are transmitted to rotate at high speed, and its vertical position can be adjusted, and furthermore, it is configured to be movable in the radial direction of the wafer 2. In this case, the movement of each grinding wheel 5, 6, 7, 8 is controlled by a predetermined cam mechanism when the wafer 2 is moved in the radial direction. The grinding operation is performed so as to follow the shape of the wafer (the shape of the wafer is not a perfect circle but has a partially flat notch).

The operation of the chamfering device shown in this figure will be explained below. First, in the initial state, the position a of the wafer 2 is
When the grinding wheel 5 is at the cutting position, the grinding wheel 5 rotates at high speed from this state to start rough grinding, and the wafer 2 rotates at a low speed in the direction of the arrow. Then, when the position a reaches the cutting position of the grindstone 6, the fine grinding by the grindstone 6 is started, and in the same way, when the position a reaches the cutting position of the grindstone 7, the top chamfering is started, and when the position a reaches the cutting position of the grindstone When the cutting position No. 8 is reached, the bottom chamfering is started. Then, when the position a reaches the cutting position of the grindstone 8 again, the chamfering process ends. That is, in the above-mentioned apparatus, each process is performed almost simultaneously, although there is a slight timing difference. The above-mentioned apparatus has the advantage that the time required for the chamfering process can be reduced to 1/3 to 1/4 of the conventional method as a result of performing each process almost simultaneously.

[The problem that the idea aims to solve]

By the way, the chamfer angle of silicon wafers etc. differs depending on the use. For example, MOS
-For ICs, the angle is generally approximately 22° on both the front and back, as shown in FIG. 8, and for bipolar ICs, the angle is generally approximately 11° on both the front and back, as shown in FIG. And if the chamfer angles are different,
It is necessary to replace the whetstone with one that corresponds to the angle, but there are problems in that the work of replacing the whetstone is complicated, and it takes time to make adjustments after installation. Therefore, the conventional chamfering apparatus shown in FIGS. 6 and 7 has a problem in that the operating rate decreases every time the chamfering angle changes. In particular, in the case of the chamfering device shown in FIG.
Since it was necessary to replace two pieces of No. 8, the reduction in operating efficiency due to replacement of the grinding wheels was more of a problem.

This idea was made in view of the above-mentioned circumstances, and it is possible to perform top chamfering and bottom chamfering at the same time, and also to create a chamfering device that does not require replacing the grindstone even when the chamfering angle changes. is intended to provide.

[Means to solve the problem]

In order to solve the above-mentioned problems, this idea involves placing multiple chamfering grindstones along the outer circumference of a wafer that rotates around its axis, and each chamfering grindstone grinds the top corner of the wafer. An upper grinding surface for grinding, and a lower grinding surface for grinding the lower corner of the wafer, which has an inclination angle different from the upper grinding surface, and each chamfering whetstone has a respective chamfering whetstone. By selectively moving the chamfering wheel in the vertical direction, when the chamfering whetstone is moved upward, the lower corner of the wafer is moved to the position where the lower corner of the wafer is ground, and when the chamfering whetstone is moved downward, It is characterized by comprising a moving means for moving the top corner of the wafer to a grinding position of the top corner of the wafer.

[Effect]

The wafer chamfering device of this invention has a plurality of chamfering grindstones arranged along the outer circumference of the wafer, provided with an upper grinding surface and a lower grinding surface with different inclination angles, and moves these chamfering grindstones in the vertical direction. By doing so, the upper surface corner of the wafer is ground by the upper grinding surface, or the lower surface corner of the wafer is ground by the lower grinding surface.

Then, by selecting the upper and lower grinding surfaces of the plurality of chamfering grindstones and moving them to the grinding position simultaneously, the upper and lower corners of the wafer are simultaneously ground.

Furthermore, by combining the vertical movement positions of the chamfering grindstones, chamfering angles with arbitrary chamfering angles are selected as the upper and lower grinding surfaces for grinding the upper and lower corners of the wafer. Furthermore, even when the chamfering angle of the wafer changes, there is no need to replace the chamfering grindstone, and productivity is significantly improved by eliminating the reduction in operating rate due to replacement of the chamfering grindstone.

〔Example〕

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

FIG. 3 is a plan view showing the configuration of an embodiment of this invention. In this figure, the same reference numerals are given to the parts corresponding to those in FIG. 7, and the explanation thereof will be omitted.

First, as is clear from FIG. 3, this embodiment differs from the chamfering device shown in FIG. 7 in that the grindstone 7,
The point is that grindstones 10 and 11 are provided instead of the grindstone 8. As shown in Figure 1A, the grindstone 10 has an upper part of the abrasive grain layer with an inclination angle of 10a for a chamfer angle of 11°, and a lower part of the abrasive grain layer with an inclination of 22° for a chamfer angle. The surface becomes the surface 10b. In addition, as shown in FIG. 1B, the grindstone 11 has an inclined surface 11a with a chamfer angle of 22° at the upper part of the abrasive grain layer, and an inclined surface 11a with a chamfer angle of 11° at the lower part.
The inclined surface 11b is designed for use. Further, each of the grindstones 5, 6, 10, and 11 is configured to be movable in the vertical direction (axial direction) as in the case of the apparatus shown in FIG. 7 described above. Note that the outer circumferential rough grinding wheel 5 and the outer circumferential fine grinding wheel 6 are exactly the same as the conventional ones,
For reference, these cross-sectional views are shown in Figure 2 A and B.

Next, the operation of this embodiment with the above configuration will be explained.

First, the upper and lower surfaces are chamfered at an angle of 11° (see Figure 9).
We will explain the operation when doing this. In this case, the fourth
As shown in FIG.
The vertical positions of the grindstone 11 are also set so that the inclined surface 11b of the grindstone 11 grinds the lower surface of the outer peripheral end of the wafer 2, as shown in FIG. After the above settings, grindstones 5, 6, 10,
The grinding operation by 11 is performed sequentially each time point a reaches the cutting position, and the grinding operation by point a is carried out again at the cutting position of the grindstone 11.
The chamfering operation ends when the point is reached.

According to the above operation, an 11° chamfer is formed on the outer circumference of the upper surface of the wafer 2 by the inclined surface 10a of the grindstone 10,
In addition, the wafer 2 is
An 11° chamfer is applied to the outer periphery of the lower surface. Therefore,
The wafer 2 is chamfered at an angle of 11° on both the upper and lower surfaces.

Next, both the upper and lower surfaces of wafer 2 are chamfered at 22° (8th
(see figure) will be explained below. In this case, contrary to the above, the grinding wheels 10, 11 are arranged so that the inclined surface 10b of the grinding wheel 10 can grind the outer peripheral lower surface of the wafer 2, and the inclined surface 11a of the grinding wheel 11 can grind the outer peripheral upper surface of the wafer 2. Set the vertical position of After this setting, the chamfering operation is performed in exactly the same manner as in the above case. As a result, grindstone 11
on the outer periphery of the upper surface of the wafer 2 by the inclined surface 11a of
A 22° chamfer is performed, and a 22° chamfer is also performed on the outer periphery of the lower surface of the wafer 2 by the inclined surface 10b of the grindstone 10. Therefore, the wafer 2 is chamfered at 22° on both the upper and lower surfaces.

As can be seen from the above description of the operation, in this embodiment, even when the chamfer angle changes, there is no need to replace the grindstones, and it is only necessary to adjust the vertical positions of the grindstones 10 and 11.

In addition, in the above-mentioned embodiment, there were two grindstones 10 and 11 for chamfering, but this invention uses 3 grindstones.
The present invention can also be applied to cases where three or more chamfering grindstones are used, and there is no need to replace the grindstone even when three or more sets of chamfer angles are combined. Also,
The combination of chamfer angles is not limited to the case where the upper and lower chamfer angles are the same as in the above-mentioned embodiments, but this invention can also be applied to cases where the upper and lower chamfer angles are different. In other words, the combination of the upper and lower chamfer angles to be set can be configured by the upper ground surface of any one of the chamfering grindstones and the lower ground surface of any other chamfer, and in the end, the combination of the upper and lower chamfer angles When using a grindstone, it is possible to chamfer four different shapes of wafers without replacing the grindstone.

[Effect of idea]

As explained above, in the wafer chamfering device of this invention, a plurality of chamfering grindstones arranged along the outer circumference of the wafer are provided with an upper grinding surface and a lower grinding surface with different inclination angles, and these chamfering By moving the grindstone in the vertical direction, the upper grinding surface grinds the upper corner of the wafer, or the lower grinding surface grinds the lower corner of the wafer. The following effects can be achieved.

By selecting the upper and lower grinding surfaces of a plurality of chamfering grindstones and moving them to the grinding position at the same time, the upper and lower corners of the wafer can be simultaneously ground.

By combining the vertical movement positions of the chamfering grindstones, it is possible to select any chamfering angle as the upper and lower grinding surfaces for grinding the upper and lower corners of the wafer. Therefore, even if the chamfer angle of the wafer changes, there is no need to replace the chamfering grindstone, and productivity can be significantly improved by eliminating the reduction in operating rate caused by replacing the chamfering grindstone. .

[Brief explanation of the drawing]

Figures 1 to 5 are diagrams for explaining one embodiment of this invention, in which Figure 1 A and B are partial sectional views of two chamfering grindstones, and Figure 2 A and B are partial sectional views of the outer periphery. FIG. 3 is a plan view showing the overall structure, and FIGS. 4 and 5 are sectional views showing different chamfering processes. 6 to 9 are diagrams for explaining the conventional example, and FIG.
The figure is a partial sectional view of the grindstone, FIG. 7 is a plan view showing the overall structure, and FIGS. 8 and 9 are sectional views showing types of chamfer angles. 10... Grindstone (chamfering grindstone), 10a... Inclined surface (upper grinding surface), 10b... Inclined surface (lower grinding surface),
11... Grindstone (chamfering grindstone), 11a... Inclined surface (upper grinding surface), 11b... Inclined surface (lower grinding surface).

Claims (1)

[Scope of Claim for Utility Model Registration] A plurality of chamfering grindstones are arranged along the outer periphery of a wafer that rotates around an axis, and each chamfering grindstone has an upper grinding surface for grinding the top corner of the wafer. and a lower grinding surface for grinding the lower corner of the wafer, which has a different inclination angle than the upper grinding surface, and each chamfering grinding wheel is provided with a grinding surface that selectively rotates each chamfering grinding wheel in the vertical direction. When the chamfering grindstone is moved upward, the bottom corner of the wafer is moved to the grinding position of the bottom corner of the wafer, and when the chamfering grindstone is moved downward, its top corner is moved to the position where the bottom corner of the wafer is ground. A wafer chamfering device comprising a moving means for moving the wafer to a grinding position at a top corner of the wafer.