Semiconductor crystal wafer manufacturing device

Abstract

To provide a semiconductor crystal wafer manufacturing device that can obtain high-precision wafer.SOLUTION: A semiconductor crystal wafer manufacturing device includes: a holding device 1 that holds a semiconductor crystal ingot W; and a cutting device 2 that supplies slurry to the semiconductor crystal ingot W and cuts the semiconductor crystal ingot W by endlessly rotating a plurality of wire saws 7 and advancing them in a direction perpendicular to the axis of the semiconductor crystal ingot W. The holding device 1 holds the semiconductor crystal ingot W via a slicing base 3. The slicing base 3 comprises: a holding block 8 that is bonded to an outer peripheral surface of the semiconductor crystal ingot W along the axis of the semiconductor crystal ingot W, allowing the wire saw to cut into the semiconductor crystal ingot W together with the semiconductor crystal ingot W; and holding pieces 9 that extend from the holding block 8 along a radial direction of the semiconductor crystal ingot W and are bonded to both end surfaces of the semiconductor crystal ingot W in the axial direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a semiconductor crystal wafer manufacturing apparatus for manufacturing wafers by slicing a cylindrical semiconductor crystal ingot into ring slices. [Background technology]

[0002] SiC wafers, which are semiconductor crystal wafers, are manufactured by processing a block of single-crystal SiC that has been crystal-grown into a cylindrical ingot, and then slicing the single-crystal SiC ingot (see, for example, Patent Document 1 below).

[0003] Conventionally, it is known that an ingot is sliced ​​using a cutting device equipped with a wire saw (see, for example, Patent Document 2 below).

[0004] The ingot to be sliced ​​by this type of cutting device is held by a holding device, which holds the ingot via a slicing base, which is detachably attached to the ingot.

[0005] After cutting through the ingot, the wire saw also cuts into the slicing base, cutting the ingot into rings without leaving any remaining slicing residue, forming thin wafers. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-15646 [Patent Document 2] Japanese Patent Application Publication No. 2023-169626 Summary of the Invention [Problem to be solved by the invention]

[0007] However, after cutting through the ingot and reaching the slicing base that is attached to the ingot, the wire saw comes into contact with the slicing base and cuts further into the slicing base together with the ingot.

[0008] At this time, the slurry supplied to the cutting position by the wire saw flows down as if being repelled by the side surface of the slicing base, and the amount of slurry that enters the cutting portion together with the wire saw decreases.

[0009] As a result, the cut surface of the wafer is rougher when cut together with the slicing base than when the ingot is cut alone before reaching the slicing base, which has the disadvantage of making it difficult to obtain high-precision wafers.

[0010] In view of the above, an object of the present invention is to provide a semiconductor crystal wafer manufacturing apparatus that can produce high-precision wafers. [Means for solving the problem]

[0011] In order to achieve this object, the present invention provides a semiconductor crystal wafer manufacturing apparatus for manufacturing wafers by slicing a cylindrical semiconductor crystal ingot into ring slices, the apparatus comprising: a holding device for holding the semiconductor crystal ingot; and a cutting device for supplying a slurry to the semiconductor crystal ingot held by the holding device and cutting the semiconductor crystal ingot by endlessly rotating a plurality of wire saws while advancing them in a direction perpendicular to the axis of the semiconductor crystal ingot, the holding device holding the semiconductor crystal ingot via a slicing base, the slicing base comprising: a holding block adhered to the outer peripheral surface of the semiconductor crystal ingot along the axis of the semiconductor crystal ingot so that the wire saws can cut the semiconductor crystal ingot together with the holding block; and holding pieces extending from the holding block along the radial direction of the semiconductor crystal ingot and adhered to both end faces of the semiconductor crystal ingot in the axial direction.

[0012] The smaller the contact area (adhesion area) of the holding block with the semiconductor crystal ingot, the more reliably the slurry can be supplied to the semiconductor crystal ingot and wire saw during cutting. However, if the contact area (adhesion area) of the holding block with the semiconductor crystal ingot is reduced, sufficient adhesive strength cannot be obtained between the holding block and the semiconductor crystal ingot, and there is a risk that the semiconductor crystal ingot will fall off the holding device.

[0013] Therefore, the present invention provides holding pieces on the holding block. The holding pieces are bonded to both axial end faces of the semiconductor crystal ingot. By providing such holding pieces, the area (bonding area) of the holding block that comes into contact with the semiconductor crystal ingot can be reduced. Specifically, for example, the width dimension of the holding block that comes into contact with the outer peripheral surface of the semiconductor crystal ingot along the circumferential direction can be reduced.

[0014] As a result, when the wire saw is cutting the semiconductor crystal ingot, the slurry flows along the holding block toward the semiconductor crystal ingot, so that the slurry can be reliably supplied to the semiconductor crystal ingot being cut.

[0015] Furthermore, since the contact area (adhesion area) between the holding block and the semiconductor crystal ingot is small, when the wire saw cuts into the holding block, the slicing of the semiconductor crystal ingot is almost complete (the semiconductor crystal wafer has almost been formed), so the semiconductor crystal wafer can be formed extremely smoothly.

[0016] Thus, according to the present invention, it is possible to provide a semiconductor crystal wafer manufacturing apparatus that can produce high-precision wafers.

[0017] In addition, in the present invention, the holding block is characterized by comprising a contact portion that contacts and adheres to the semiconductor crystal ingot, and a pair of side portions formed on both sides of the contact portion in the circumferential direction of the semiconductor crystal ingot, and both side portions are inclined in directions that intersect with each other on the semiconductor crystal ingot side.

[0018] Since the two side surfaces are inclined in directions that intersect with each other inside the semiconductor crystal ingot, the corners at the boundaries between the contact portions and each side surface are all obtuse angles. This makes it easier for the slurry flowing down the side surfaces to adhere to the semiconductor crystal ingot compared to when the corners at the boundaries between the contact portions and each side surface are right angles or acute angles. This makes it possible to more smoothly manufacture semiconductor crystal wafers with smooth cut surfaces and high precision. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is an explanatory diagram showing a front view of a main configuration of a semiconductor crystal wafer manufacturing apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a side view of FIG. 1. [Figure 3] FIG. 2 is an explanatory diagram showing the state when the ingot is cut. [Figure 4] FIG. 4 is an explanatory diagram showing the shape of a holding block. [Figure 5] 4A and 4B are explanatory diagrams showing the function of the holding block when cutting the semiconductor crystal ingot. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the present invention will be described with reference to the drawings. The device of this embodiment slices a cylindrical semiconductor crystal ingot W (hereinafter referred to as ingot W) into circular slices to form circular thin plate-shaped semiconductor crystal wafers, and is equipped with a holding device 1 and a cutting device 2, as shown in Figures 1 and 2.

[0021] The holding device 1 holds the ingot W via a slicing base 3, which will be described later. The ingot W held by the holding device 1 has a plurality of grooves formed in advance on its outer circumferential surface, as shown in FIG.

[0022] The grooves are formed in an annular shape around the entire circumferential direction of the ingot W, and are spaced at predetermined intervals along the axial direction of the ingot W. For ease of explanation, the groove intervals are shown enlarged in Fig. 2, but in reality, they are formed at extremely small intervals to accommodate the thickness of the wafers to be manufactured.

[0023] As shown in FIG. 1, the cutting device 2 includes a plurality of (three in this embodiment) bobbins 4, 5, and 6, and a wire saw 7 that is stretched across the bobbins 4, 5, and 6 and rotates endlessly.

[0024] 2, each of the bobbins 4, 5, and 6 has a pulley groove formed thereon corresponding to each groove of the ingot W. By having the wire saw 7 stretched across the pulley groove, the rotating wire saw 7 is maintained with high positional accuracy.

[0025] When cutting the ingot W by the cutting device 2, the ingot W held by the holding device 1 is lowered relative to the rotating wire saw 7, as shown in Fig. 3. At this time, slurry is supplied to the position where the ingot W is to be cut by the wire saw 7, allowing the cutting operation to proceed smoothly.

[0026] Here, the slicing base 3, which is the gist of the present invention, will be described in detail. As shown in FIGS.

[0027] The holding block 8 has an elongated shape extending along the axis of the ingot W, and is bonded to the outer peripheral surface of the ingot W. The holding pieces 9 extend along the radial direction of the ingot W, and are bonded to both end surfaces of the ingot W in the axial direction. The holding pieces 9 are integrally connected to both ends of the holding block 8.

[0028] When viewed in cross section as shown in Figure 4, the holding block 8 has an inverted trapezoidal shape with an upper base larger than a lower base, and an adhesive surface 10 (contact portion) corresponding to the lower base is adhered to the outer peripheral surface of the ingot W.

[0029] In addition, a pair of side portions 11, 12 on both sides of the holding block 8 (on both sides in the circumferential direction of the ingot W) are inclined in directions that intersect with each other on the ingot W side, as shown by imaginary extension lines a, b in FIG.

[0030] The slicing base 3 is provided with the holding pieces 9, which enable it to reliably hold the ingot W. As a result, when the circumferential direction of the ingot W is the width direction of the holding block 8, the width dimension of the adhesive surface 10 of the holding block 8 can be made relatively small, and the side surfaces 11 and 12 can be satisfactorily inclined.

[0031] By providing the slicing base 3 having such a shape, as shown in Fig. 5, the flow of slurry supplied during cutting with the wire saw 7 is guided in the direction of adhesion to the ingot W as indicated by the arrow s due to the inclination of the side portions 11, 12. This ensures that the slurry is reliably supplied into the grooves of the ingot W, especially when cutting the ingot W nears the end. Therefore, the ingot W can be sliced ​​smoothly and accurately into round slices, and high-precision wafers can be obtained. [Explanation of symbols]

[0032] W...semiconductor crystal ingot, 1...holding device, 2...cutting device, 3...slicing base, 7...wire saw, 8...holding block, 9...holding piece, 10...adhesion surface (contact portion), 11, 12...side portion.

Claims

1. A semiconductor crystal wafer manufacturing apparatus for manufacturing wafers by slicing cylindrical semiconductor crystal ingots into ring slices, a holding device for holding the semiconductor crystal ingot; and a cutting device for supplying a slurry to the semiconductor crystal ingot held by the holding device and cutting the semiconductor crystal ingot by endlessly rotating a plurality of wire saws and advancing them in a direction perpendicular to the axis of the semiconductor crystal ingot, the holding device holds the semiconductor crystal ingot via a slicing base; a semiconductor crystal wafer manufacturing device, characterized in that the slicing base comprises: a holding block that is adhered to the outer peripheral surface of the semiconductor crystal ingot along the axis of the semiconductor crystal ingot so that the wire saw can cut into the semiconductor crystal ingot together with the holding block; and holding pieces that extend from the holding block along the radial direction of the semiconductor crystal ingot and are adhered to both end surfaces of the semiconductor crystal ingot in the axial direction.

2. the holding block includes a contact portion that contacts and adheres to the semiconductor crystal ingot, and a pair of side portions formed on both sides of the contact portion in the circumferential direction of the semiconductor crystal ingot; 2. The semiconductor crystal wafer manufacturing apparatus according to claim 1, wherein both side surfaces are inclined in directions intersecting each other on the semiconductor crystal ingot side.

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