JPH01238906A - Method and apparatus for slicing wafer from semiconductor material - Google Patents

Abstract

PURPOSE:To contrive to simplify and miniaturize the structure of an apparatus and to enhance the working efficiency of the apparatus by a method wherein a cut-out wafer, which is produced by slicing semiconductor material having its edge face polished with a band saw, is suckingly held by utilizing the polished face of the water as a suction face in order to polish the cut face of the water. CONSTITUTION:The edge face of semiconductor material 6 is polished with polished wheelstone 16, which is arranged near a band saw 12. After the finish of the polishing of said edge face, the semiconductor material is sliced with the band saw 12. After that, each time one wafer 9 is cut down, the edge face of the semiconductor material 6 is polished. By repeating the polishing of edge face and the slicing, wafers 9, the edge face of each of which has been polished, are cut out one by one from the semiconductor material 6. By sucking the polished face of the cut-out wafer 9 with a proper sucking means 19, the face which is cut with the band saw 12 is polished flat with a polishing wheel 17.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a wafer cutting method and an apparatus for cutting out a wafer from a semiconductor material such as a silicon ingot, and polishing the cut surface of the cut wafer as necessary. It is related to.

[Conventional technology]

Inner peripheral blades are widely used as a means for cutting out wafers from semiconductor materials such as gallium arsenide ingots, silicon ingots, and gallium phosphorous ingots.

As shown in FIG. 6, this type of internal peripheral cutter has abrasive grains electrodeposited on the inner peripheral edge of a donut-shaped base 1 to form a cutting edge 2, and the outer peripheral edge of the base l. Generally, a plurality of holes 3 are arranged at equal intervals around the circumference, and the holes are used for mounting. This type of inner circumferential cutter 4 is installed in a holder 5 as shown in FIG. 5 by applying tension F to the inner circumferential cutter 4 outward in the radius using the hole 3 and keeping the cutting edge 2 under tension. be done. and,
With the inner peripheral blade 4 attached, the thread rudder 5 is rotated using an appropriate driving means, and the semiconductor material 6 held by the ingot holding means is inserted into the center hole of the inner peripheral blade 4, and the semiconductor material 6 is inserted into the center hole of the inner peripheral blade 4. By cutting in the direction, the semiconductor material 6 is sliced and a wafer is cut out. Usually, a suction table 7 is arranged inside the holder 5 to receive the cut wafer by suction.

The cut wafer is taken out of the holder 5 by an appropriate means, and the next step is cleaning and polishing of the cut surface.

[Problem to be solved by the invention]

However, in the method of slicing semiconductor material using an inner peripheral blade, the outer diameter of the inner peripheral blade is approximately 1 m, so there is a problem that the entire device equipped with this becomes large. In addition, when cutting with an internal cutting edge, in order to perform high-precision machining, it is necessary to tighten the cutting edge and attach it to the holder 5. Because the tension is unbalanced, the axis tends to shift and the cutting edge 2 is easily deformed, making it very difficult to adjust the tension of the cutting edge 2, which not only causes poor workability but also causes damage to the cutting edge. There was an inconvenience that if the blade 2 was deformed, the machining accuracy would deteriorate.

In addition, a suction table 7 for holding wafers must be provided inside the holder 5, and the wafers suctioned to the table 7 are taken out and sent to the next process.
The wafer removal operation must be carried out through the center hole 8 of the inner circumferential cutter 4 without touching the cutting edge 2, which imposes many restrictions, inevitably complicating the equipment configuration, and making it difficult to design the equipment. The disadvantage is that the degree of freedom is also limited.

By the way, since the cut surface of the wafer 9 cut out from the semiconductor material 6 is uneven as shown in FIG. 7(a), one end surface is placed on the chuck table 1 as shown in FIG. 7(b).
When the surface is polished using the polishing whetstone 11 while the chuck table 1o is suctioned and fixed, even if it appears to be polished flat, when the suction of the chuck table 1o is released, the surface is polished as shown in FIG. 7(C). Due to springback, the unevenness on the suction surface 9a side appears on the surface side, resulting in an inconvenience that the polished surface becomes uneven.

In order to eliminate this inconvenience, the end face of the semiconductor material 6 is polished to make it flat and then sliced, the flat face of the cut wafer 9 is sucked onto the chunk table 10 side, and the cut face is polished. For example, even after the suction is released, no unevenness appears on the surface side, and a flat and highly accurate polished surface can be obtained.

From this point of view, it has been proposed to separately provide a polishing wheel for polishing the end face of the semiconductor material near the inner peripheral blade.

However, since the inner peripheral cutter is originally a large-sized device, there is a problem in that if a grinding wheel is provided outside the inner peripheral cutter, as shown by the chain line in FIG. 5, the device becomes even larger. Therefore, in order to avoid increasing the size of the device as much as possible, the polishing wheel 11 is provided inside the holder 5, but this has the disadvantage that the device configuration becomes even more complicated.

The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to reduce the size and simplicity of the device, and also to increase the degree of freedom in device design, as well as to improve workability and processing accuracy. It is an object of the present invention to provide a method for cutting out a wafer from a semiconductor material and an apparatus therefor, which can be used together.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows. That is, the first method of cutting out a wafer from a semiconductor material according to the present invention is characterized in that the end face of the semiconductor material is polished, and after this polishing is completed, the semiconductor material is sliced with a band saw. The second method is to polish the end face of the semiconductor material, and after the polishing is completed, slice the semiconductor material with a band saw to cut out the wafer, and then attach the cut wafer to the wafer using the polished side as the suction surface. The device is characterized in that the wafer is suctioned and held by a suction means and the cut surface by the band saw is polished by a polishing stone, and the device for cutting out a wafer from a semiconductor material of the present invention firstly comprises a hand saw for slicing the semiconductor material. ,
The apparatus of the present invention is characterized in that it includes a polishing wheel disposed near the band saw and polishing the end surface of the semiconductor material. A polishing whetstone, a band saw for slicing the semiconductor material whose one end surface has been polished by the first polishing whetstone, a wafer suction means for suctioning and holding the wafer cut from the semiconductor material by the band saw from the polished surface side, and the wafer. The present invention is characterized in that a second polishing grindstone is arranged to polish the cut surface of the wafer that is being sucked by the sucking means by the band saw.

[Effect]

In the present invention configured as described above, the semiconductor material is a polishing wheel (first grindstone) disposed near the band saw.
The end face is polished by a grinding wheel), and after the end face polishing is completed, the semiconductor material is sliced by a band saw. Each time a wafer is cut out, the semiconductor material is polished at its end face, and by repeating this end face polishing and slicing, wafers with one end face polished are cut out one after another from the semiconductor material.

In an apparatus equipped with a second polishing wheel at a position downstream of the band saw, the polished side of the wafer cut out by the band saw is sucked by a suitable suction means,
The cut surface cut by the band saw is polished flat by a second polishing stone.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an apparatus configuration showing a first embodiment of the present invention. The apparatus shown in FIG. 1 is an example of an apparatus in which the semiconductor material held by the ingot holding means is sliced after its end face is polished.

In the figure, a band saw 12 for cutting a semiconductor material 6 such as a silicon ingot has a cutting edge 2 formed by forming abrasive grains on the edge of a band-shaped substrate 13 made of steel, stainless steel, etc. by electrodeposition or the like. .

This band saw 12 has a driving pulley 14 and a driven pulley 15.
It is hooked up to 914.15 and travels around between both Boo 914.15.

A grinding wheel 1 is located near the band saw 12.
6 is rotatably arranged by the drive of a motor (not shown). Regarding the arrangement relationship between the band saw 12 and the polishing wheel 16, for example, as shown in FIG. , as shown in FIG. 3, a band saw 12 is installed on the upstream side, and a grinding wheel 1 is installed on the downstream side.
6 may be provided. In either case, a suction table 19 for suctioning and holding a wafer cut out from the semiconductor material 6 is placed on the opposite side of the band saw 12.
It is provided so as to face the material 6 and to be interlocked with the movement of the cut in the material 6.

The first embodiment is constructed as described above, and its operation will be explained below. In the case of the arrangement shown in FIG. 2, first, the polishing wheel 16 rotating at the upstream position
Edge polishing of the semiconductor material 6 is performed. After this end face polishing is completed, if the semiconductor material 6 is sent downstream,
The semiconductor material 6 is cut by a band saw, and the cut wafer is collected from the polishing surface by a suction table 19 and transported to the next process.

When cutting the semiconductor material 6, the semiconductor material 6 can be polished by shifting the polishing surface 16a of the polishing wheel 16 a distance t in front of the end surface 12a of the band saw 12 by the thickness of the wafer (to the left in the figure). After that, the polished surface 16a
By moving downstream in parallel with the semiconductor material 6, the semiconductor material 6 is automatically sliced to the desired thickness of the wafer.

After this slicing is completed, the semiconductor material 6 is moved back to its original upstream position, then fed forward (towards the left in the figure), and its end face is polished by the polishing wheel 16 before being ready for the next slicing process. Transition.

By repeating the end face polishing and slicing in this manner, wafers of a predetermined thickness are successively cut out.

Further, in the case of the arrangement shown in FIG. 3, the semiconductor material 6 whose end face has been polished is cut by the band saw 12 at the upstream position, and after the cutting is completed, the material 6 is sent to the downstream position where the polishing wheel is used. 16, the end face of the cut surface is polished. After the end face polishing is completed, the semiconductor material 6 returns to its original upstream position. Then, the material 6 is sent forward (to the left in the figure) by the thickness of the wafer and sent to the hand saw 12 side where it is sliced.

In this manner, in both the arrangements shown in FIGS. 2 and 3, after the end face polishing of the semiconductor material 6 is completed, the semiconductor material 6 is sliced and the wafer is cut out.

As described above, according to the embodiment of the youngest brother 1, the end face of the semiconductor material 6 is polished and then the same material 6 is sliced, so that one side of the cut wafer is always polished. Therefore, the wafer is suctioned and fixed to the chuck can bull 10 using this polished surface as the suction surface as shown in FIG. Even if the adsorption of the chuck table IO is released later, as shown in Fig. 7(c), "
The unevenness of the wafer suction surface 9a does not appear on the surface side due to springback, and as a result, the cut surface by the band saw 12 can be polished flat.

In addition, the tension of the cutting edge 2 of the band saw 12 is
4. This can be achieved simply by moving one (or both) of Since there is no deformation, the workability of tensioning the cutting edge is greatly improved.

Furthermore, the diameter of the pulleys 14, 15 on which the band saw 12 is attached can be made sufficiently smaller than the diameter of the inner peripheral blade of the conventional example, so that the device can be significantly miniaturized compared to a cutting device using an internal peripheral blade. Furthermore, since the device configuration is simple, the cost of the device can be reduced and the economic benefits are great. Moreover,
Since a wide free space is formed near the band saw 12, the polishing wheel 16 and the wafer 9 recovery device can be arranged in any manner in the free space, which increases the degree of freedom in device design. The device configuration and device arrangement can be optimally set according to the processing line situation.

Furthermore, due to the configuration of the device, it is easy to align the cutting edge 2 of the band saw 12 and the polishing wheel 16 in parallel, which is desirable in terms of improving the polishing accuracy and processing efficiency.

-ta, although the band saw 12 has the advantage of having a simple device configuration and being able to downsize the device, the cutting surface is rougher than that of an internal blade, and as mentioned above, this rough surface is As shown in Figure (b), when the surface is polished by suction with the chuck table 10, there is a drawback that the unevenness of the suction rough surface becomes larger due to springback due to the roughness of the suction surface. has not been used as a cutting device for semiconductor materials.

In this embodiment (the present invention), the band saw 12 has a grinding wheel 16.
By combining the above, and cutting the semiconductor material 6 after polishing its end face, the drawback of the band saw 12 (the drawback that large irregularities on the suction surface side appear on the polished surface when polishing the surface of the wafer) is solved, and By taking advantage of the various advantages of the band saw 12, it is possible to provide a device that is superior to the proposed device in which an abrasive wheel is combined with an inner peripheral blade.

FIG. 4 shows a second embodiment of the invention.

This second embodiment is configured to slice the semiconductor material 6 after polishing the end face of the semiconductor material 6 in the same manner as the first embodiment, but differs from the first embodiment. , a dedicated grinding wheel for polishing the cut surface of the cut wafer is provided separately, and the cutting of the wafer and the polishing of the cut surface of the wafer are performed continuously during online cutting. . In the description of the second embodiment, the same members as in the first embodiment will be denoted by the same reference numerals, and their repeated explanation will be omitted.

In FIG. 4, a first polishing wheel 16 is provided on the upstream side of the cutting line, and a band saw 12 is provided on the downstream side, and as in the first embodiment, the end face of the semiconductor material 6 is polished on the first grinding wheel 16. The material 6 is then sliced by the band saw 12 to cut out the wafer 9. When cutting out this wafer 9,
A suction table 19 serving as a wafer suction means faces the polished end surface of the semiconductor material 6 with the band saw 12 in between, and as the material 6 moves in the cutting direction, the suction table 19
9 also moves in the same direction to ensure that the cut wafer is not dropped (to ensure that it is held by suction).

A second abrasive grindstone 17 is provided at a position further downstream of the hand saw 12 and is rotatably driven by a motor (not shown). In the embodiment of the youngest brother 2, the wafer 9 cut out by the hand saw 12 is
The surface polished by the second polishing wheel 16 is used as a suction surface to be attracted to the suction table 19, and the movement of the table 19 brings it to the polishing position of the second polishing wheel 17. and,
The cut surface of the wafer 9 by the band saw 12 is polished by the second polishing whetstone 17 .

When polishing this cut surface, the surface (cut surface) of the wafer 9 is polished by the second polishing wheel 17 because the surface that has already been polished flat is suctioned to the suction table 19 as described above. Even after the suction of the wafer 9 is released, the unevenness on the suction surface side caused by the springback does not appear on the surface side, and the wafer 9 is flattened on both sides by the polishing wheels 16 and 17. Polished.

After the polishing by the second polishing whetstone 17 is completed, the wafer 9 is transferred to a transfer suction table 18 at a downstream position, and is transported to a desired process position such as cleaning.

As mentioned above, in addition to obtaining the same effects as the first embodiment, the second and youngest embodiment also continuously performs wafer cutting and polishing on both sides of the cut wafer on the cutting line. As a result, a new effect can be obtained in that the processing steps for the wafer 9 are made more efficient.

The present invention is not limited to the above-mentioned embodiments, and can take various embodiments. For example, in each of the above embodiments, the suction table 19 for receiving and receiving the wafer 9 cut out from the semiconductor material 6 is moved continuously following the movement of the semiconductor material 6 in the cutting direction, and the suction surface of the suction table is moved to receive the wafer 9 cut out from the semiconductor material 6. However, unlike this, the suction table 19 is not moved to follow, but is kept waiting at a position where cutting out of the wafer 9 is completed, and the cut out wafer 9 is received at that position. Furthermore, the polishing wheels 16 and 17 are not limited to the wheel type, but may be of the heald type. Furthermore, a polishing stone may be fixed to the surface of the band saw by electrodeposition or the like, so that the band saw itself has a polishing function.

〔Effect of the invention〕

Since the present invention is configured to slice the semiconductor material using a band saw, the device configuration can be simplified and the device can be made smaller compared to a device using an internal peripheral blade, and the device cost can be reduced. I can figure it out. Further, since the degree of freedom in device design can be increased, the device can be designed in an optimal form depending on the situation of the cutting line. Additionally, equipment using an internal blade requires a complicated procedure to take out the sliced wafer from inside the equipment, but the method using the band saw of the present invention eliminates this complicated procedure, making the work easier. Speed can be achieved and work efficiency can be increased.

In addition, since semiconductor materials are always sliced after their end faces are polished, when polishing the cut surfaces of cut out waes, the polished surfaces are adsorbed on a suction table before being polished. By doing this, the conventional problem of unevenness appearing on the suction side surface due to the springback phenomenon after the polishing of the surface (cut surface) is completed can be reliably prevented. A polished surface will be obtained.

When polishing the cut surface of the wafer, in a configuration in which a dedicated polishing wheel (second polishing wheel) for polishing is placed on the cutting line, the semiconductor material is sliced and the cut wafer is polished continuously. This will greatly improve the efficiency of the wafer processing process.

[Brief explanation of the drawing]

FIG. 1 is a perspective configuration diagram showing the first embodiment of the present invention;
3 and 3 are explanatory diagrams showing an example of the arrangement of the bunt saw and the grinding wheel in the same embodiment, FIG. 4 is an explanatory diagram showing the configuration of the second embodiment of the present invention, and FIG. FIG. 6 is an explanatory cross-sectional view showing a semiconductor material cutting device, FIG. 6 is an explanatory view of an inner peripheral blade, and FIG. 7 is an explanatory view showing a polishing mode of a cut surface of a wafer cut out from a semiconductor material. ■... Base, 2... Cutting edge, 3... Hole, 4...
Inner peripheral blade, 5... Holder, 6... Semiconductor material, 7...
・Suction table, 8... Center hole, 9... Ueno 1
．． 9a...Adsorption surface, lO...Chuck table, 1
1... Polishing whetstone, 12... Nokundo saw, 12a.
... End face, 13 ... Board, 14 ... Drive pulley, 1
5... Driven pulley, 16... Grinding wheel (first grinding wheel), 17... Second grinding wheel, 18... Suction table for transportation, 19... Suction table. Applicant Stock Company Disco Agent Patent Attorney Igarashi Kiyoshi 1st District! 2 Fourth Snake

Claims (4)

[Claims] (1) A cutting method for cutting out a wafer by slicing a semiconductor material, which comprises polishing the end face of the semiconductor material, and slicing the semiconductor material using a band saw after the polishing is completed. (2) A processing device for cutting out a wafer from a semiconductor material, comprising a band saw for slicing the semiconductor material, and a polishing wheel disposed near the band saw for polishing the end face of the semiconductor material. (3) Polish the end face of the semiconductor material, and after completing this polishing, slice the semiconductor material with a band saw to cut out a wafer, and hold the cut wafer by suction with a wafer suction means with the polished side as the suction surface. A method for cutting out a wafer from a semiconductor material, comprising polishing the cut surface by the band saw with a grindstone. (4) a first polishing wheel for polishing the end face of the semiconductor material;
A band saw for slicing the semiconductor material whose one end surface has been polished by the first polishing grindstone; a wafer suction means for suctioning and holding the wafer cut from the semiconductor material by the band saw from the polished surface side; A wafer cutting processing apparatus from a semiconductor material, characterized in that a second polishing wheel for polishing the cut surface of the wafer cut by the band saw is arranged.