JPH0768537A - Cutting of semiconductor ingot - Google Patents

Abstract

PURPOSE:To prevent the chipping or cracking of a semiconductor wafer immediately before cutting off by bonding silicon plates to both side surfaces of a slice stand in such a state that the leading ends thereof are closely bonded to the outer peripheral surface of a semiconductor ingot. CONSTITUTION:The rotary stand 11 of a cutter is rotated around a rotary shaft 14 and a feed table 9 is moved in the direction shown by an arrow A to cut a semiconductor ingot 1 by an inner peripheral blade 12. When the semiconductor ingot 1 becomes a cutting completion stage by the advance of cutting, the edge of the inner peripheral blade 12 begins to cut the leading end parts of the silicon plates bonded to both side surfaces of a slice stand 2. When the cutting of the semiconductor ingot 1 is completed and the edge of the inner peripheral blade 12 reaches the almost central part of the thickness of the slice stand 2, the movement of the feed stable 9 is stopped and the feed table 9 is returned to the position before the start of cutting. Subsequently, the thickness of a wafer to be cut is determined and the cutting of the semiconductor ingot l is repeated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a semiconductor ingot into a thin plate to form a semiconductor wafer.

[0002]

2. Description of the Related Art Conventionally, an inner peripheral blade type cutting apparatus has been used to cut a silicon single crystal ingot into a thin plate to form a silicon wafer. That is, as shown in FIG. 3, the inner blade blade rotates about the rotation axis, while the ingot is attached to the feed table, and before cutting, the ingot is positioned inside the inner blade blade, and the feed table moves. Cutting of the semiconductor ingot is started. As shown in FIG. 5, the semiconductor ingot 21 has a slice base 22 attached to the outer peripheral surface thereof in advance, and a wafer is formed by cutting from the side opposite to the side where the slice base 22 is attached. It In this case, the semiconductor ingot 21
The wafers cut from are put in a state of being continuously connected by the slicing table 22. Conventionally, this slice base 22 prevents clogging of the blade edge of the inner peripheral blade,
Also, carbon is used because it is easy to process and is inexpensive.

[0003]

However, since the slicing table made of carbon has a large hardness difference with the semiconductor ingot, there is a large difference in cutting resistance just before the semiconductor ingot is cut and separated. Then, the blade edge of the inner peripheral blade was vibrated. For this reason, there is a problem in that this vibration causes a chip or a crack in the cut end portion of the wafer. Also, especially 4
In the case of a wafer having a thickness of 00 μm or less, there is a problem that the weight of the wafer cannot be supported only by the cut carbonaceous slicing table, and as a result, the wafer may drop.

In view of the above problems, it is an object of the present invention to provide a semiconductor ingot cutting method capable of preventing edge chipping or cracking of a semiconductor wafer on the verge of being cut off.

[0005]

Therefore, in the present invention, the slice base is attached to the outer peripheral surface of the semiconductor ingot, and in the method of cutting the semiconductor ingot by the inner peripheral blade of the cutting blade, on both side surfaces of the slice base, The tip of the silicon ingot is brought into close contact with the outer peripheral surface of the semiconductor ingot, and a silicon plate is attached.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a semiconductor ingot and a slicing table according to the present invention, FIG. 2 is a plan view of a semiconductor ingot and a slicing table according to the present invention, and FIG. 3 is a schematic view of an ingot cutting method according to the present invention. 4 is a perspective view showing a state of the semiconductor ingot and the slice base after cutting, and FIG. 5 is a perspective view of the conventional semiconductor ingot and the slice base.

As shown in FIGS. 1 and 2, a semiconductor ingot 1 is provided with a slicing table 2 made of carbon along the outer peripheral surface of the semiconductor ingot 1 with an epoxy resin adhesive 7. The adhesive surface 6 of the slice base 2 is provided so as to follow the circumference of the semiconductor ingot 1 in the axial direction.

A silicon plate 3 and a silicon plate 4 are attached to both side surfaces of the slice base 2. An epoxy resin adhesive 7 is used to bond the silicon plate 3 and the silicon plate 4 to the slice base 2. At the time of this bonding, the silicon plate tip portion 3a facing the semiconductor ingot 1
Is attached so as to be in close contact with the outer peripheral surface of the semiconductor ingot 1, and the tip portion 4a of the silicon plate 4 on the other side surface is similarly formed. It should be noted that the silicon plate 3 and the silicon plate 4 attached to both sides of the slicing table 2 can be used by cutting a defective silicon wafer or an inspected silicon wafer that has been discarded so far.

As described above, the semiconductor ingot 1 provided with the slicing table 2 having the silicon plate 3 and the silicon plate 4 attached to both side surfaces thereof has the upper surface of the mounting block 8 of the cutting device as shown in FIG. It is adhered to the bottom surface, and this is vertically attached to the attachment portion 10 of the feed table 9 so that the slicing table 2 becomes the cutting end portion.

Next, the operation of this embodiment will be described.
The rotary table 11 of the cutting device is rotated about the rotary shaft 14, the feed table 9 is moved in the direction of arrow A, and the semiconductor ingot 1 is cut by the inner peripheral blade 12. When the cutting proceeds and the semiconductor ingot 1 is completely cut, the cutting edge 13 of the inner peripheral blade 12 has the tip portion 3 of the silicon plate 3 attached to both side surfaces of the slicing table 2.
a and the tip part 4a of the silicon plate 4 start to be cut. At this time, the semiconductor ingot 1 and the silicon plate 3 and the silicon plate 4 are made of the same material, silicon, and the tip portion 3a of the silicon plate 3 and the tip portion 4a of the silicon plate 4 adhere to the semiconductor ingot 1. Since it is affixed on the plate, there is almost no change in cutting resistance. As a result, it is possible to prevent the vibration and bending of the blade edge 13 of the inner peripheral blade 12 when the semiconductor ingot 1 is completely cut, which has occurred conventionally.

As shown in FIG. 2, when the cutting of the semiconductor ingot 1 is completed and the cutting edge 13 of the inner peripheral blade 12 reaches near the center of the thickness of the slicing table 2, the feed table 9 is stopped from moving. The table 9 is returned to the position before the start of cutting. Next, the thickness of the wafer 5 to be cut next is determined, the feed table 9 is moved again in the direction of arrow A, and the cutting of the semiconductor ingot 1 is repeated.

By repeating this cutting operation, as shown in FIG. 4, the wafer 5 is completely cut by the slicing table 2 and the silicon plate 3 and the silicon plate 4 attached to both side surfaces thereof in a continuously connected state. To do. Here, since the silicon plate 3 and the silicon plate 4 on both sides of the slicing table 2 are highly rigid, the slicing table 2 is prevented from bending due to the weight of the cut wafer 5. As a result, it is possible to prevent the wafer from dropping, which has occurred in the conventional cutting method using only the carbon slicing table 2.

[0013]

According to the present invention, since the semiconductor ingot is cut by the above method to form a semiconductor wafer, the following excellent effects can be obtained. (1) Since the tip of the silicon plate is attached to the slicing table so as to be in close contact with the semiconductor ingot, the cutting resistance does not change, which causes vibration of the inner blade that occurs just before the end of cutting of the semiconductor ingot. It can be prevented. As a result, it is possible to prevent edge chipping or cracking that occurs at the end of cutting of the semiconductor wafer. In particular, in the case of cutting an extremely thin semiconductor wafer having a thickness of 400 μm or less, it can be reduced by about 70%. (2) Since the above effects can be obtained by pasting silicon plates on both sides of the slicing table, it is not necessary to process a special material to use it as a slicing table, and the processing conventionally used is easier. The carbon can be used as is for the slice table. (3) The silicon plates attached to both sides of the slicing table are
It is possible to cut and use defective wafers and wafers that have already been inspected that have been discarded. Therefore, it is easy to process and extremely economical in terms of cost. (4) The rigidity of the silicon plate also prevents the wafer from dropping due to the weight of the wafer, which has been caused by the conventional cutting method using only a carbon-based slicing table.

[Brief description of drawings]

FIG. 1 is a perspective view of a semiconductor ingot and a slice base according to the present invention.

FIG. 2 is a plan view of a semiconductor ingot and a slice base according to the present invention.

FIG. 3 is a schematic diagram of an ingot cutting method according to the present invention.

FIG. 4 is a perspective view showing a state of the semiconductor ingot after cutting.

FIG. 5 is a perspective view of a conventional semiconductor ingot and a slicing table.

[Explanation of symbols]

 1 Semiconductor Ingot 2 Slice Table 3 Silicon Plate 3a Silicon Tip 4 Silicon Plate 4a Silicon Tip 5 Wafer 6 Adhesive Surface 7 Adhesive 8 Mounting Block 9 Feed Table 10 Mounting Part 11 Rotating Platform 12 Inner Blade Blade 13 Blade Edge 14 Rotating Shaft 21 Semiconductor Ingot 22 Slice Stand 23 Adhesive Surface 24 Adhesive

Claims (1)

[Claims] 1. A method of adhering a slicing table to an outer peripheral surface of a semiconductor ingot, and cutting the semiconductor ingot with an inner peripheral blade of a cutting blade, wherein both ends of the slicing table are provided with their tips at the outer periphery of the semiconductor ingot. A method for cutting a semiconductor ingot, which is characterized in that a silicon plate is attached so as to be in close contact with the surface.