JP7007625B1 - Manufacturing method and equipment for semiconductor crystal wafers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing a semiconductor crystal wafer capable of easily and surely manufacturing a high-quality semiconductor crystal wafer. A method for manufacturing a SiC wafer, which is a semiconductor crystal wafer, is a method for obtaining a SiC wafer in which the surface of a wafer cut into slices from a SiC ingot ground into a cylindrical shape is subjected to high-precision grinding. , A groove processing step (STEP100 / FIG. 1), a cutting and polishing step (STEP200 / FIG. 1), a first surface processing step (STEP300 / FIG. 1), and a second surface processing step (STEP400 / FIG. 1). .. [Selection diagram] Fig. 1

Description

The present invention relates to a method and an apparatus for manufacturing a semiconductor crystal wafer in which the surface of a wafer cut into slices from a semiconductor crystal ingot ground into a cylindrical shape is subjected to high-precision grinding.

Conventionally, as a method for manufacturing a SiC wafer, which is a semiconductor crystal wafer of this type, as shown in Patent Document 1 below, as a wafer shape forming step, a mass of single crystal SiC crystal-grown is processed into a columnar ingot. The ingot forming process, the crystal orientation forming process in which a notch is formed in a part of the outer periphery so as a mark indicating the crystal orientation of the ingot, and the single crystal SiC ingot are sliced and processed into a thin disk-shaped SiC wafer. A slicing step, a flattening step of flattening a SiC wafer using abrasive grains having a modified moth hardness, a marking forming step of forming a marking, and a chamfering step of chamfering the outer peripheral portion are included, and then processing is performed. The altered layer removing step includes a processed altered layer removing step of removing the processed altered layer introduced into the SiC wafer in the preceding step, and finally, as a mirror polishing step, the mechanical action of the polishing pad and the chemical of the slurry. A method for manufacturing a SiC wafer including a chemical mechanical polishing (CMP) step in which polishing is performed in combination with various actions is known.

Japanese Unexamined Patent Publication No. 2020-15646

However, the conventional method for manufacturing a SiC wafer has many problems that the manufacturing process is complicated, the apparatus configuration is complicated, and the manufacturing cost is high.

On the other hand, if the manufacturing process is simplified, it becomes difficult to stably obtain the quality required for the SiC wafer.

Therefore, an object of the present invention is to provide a method and an apparatus for manufacturing a semiconductor crystal wafer, which can easily and surely manufacture a high-quality semiconductor crystal wafer.

The method for manufacturing a semiconductor crystal wafer according to the first invention is a method for manufacturing a semiconductor crystal wafer in which a wafer is cut into slices from a semiconductor crystal ingot ground into a cylindrical shape.
A grooving step of forming a plurality of concave grooves orbiting the entire side surface of the semiconductor crystal ingot, and
The semiconductor crystal ingot is cut into slices by advancing while rotating a plurality of wires arranged in the plurality of concave grooves formed in the groove processing step, and is arranged at each of the rear positions of the plurality of wires. The plate-shaped body is provided with a cutting and polishing step of polishing the cut surface on the side surface of the plate-shaped body by moving the plate-shaped body forward while swinging .
In the cutting and polishing step, the pedestal for advancing the wire and the pedestal for advancing the plate-shaped body are integrally configured, so that cutting by the wire and polishing by the plate-shaped body can proceed at the same time. It is characterized by .

According to the method for manufacturing a semiconductor crystal wafer of the first invention, in the groove processing step, a concave groove is formed in advance on the entire side surface of the semiconductor crystal ingot, so that the semiconductor crystal ingot is formed by a wire using the concave groove as a guide. It can be cut into slices with high accuracy.

Here, a plate-shaped body to be polished while swinging the cut surface is placed behind the wire to be cut while rotating around the semiconductor crystal ingot, and the plate-shaped body is advanced as the wire progresses to perform cutting. At the same time, the waviness and streaks on the cut surface can be polished and removed, so-called transfer can be prevented and a high-quality semiconductor crystal wafer can be obtained. Complex manufacturing processes such as multiple laps of the primary to quaternary can be greatly simplified.

As described above, according to the method for manufacturing a semiconductor crystal wafer of the first invention, a high-quality semiconductor crystal wafer can be easily and reliably manufactured.

The semiconductor crystal wafer manufacturing apparatus of the second invention is a semiconductor crystal wafer manufacturing apparatus that cuts a wafer into slices from a semiconductor crystal ingot ground into a cylindrical shape.
A wire saw portion that advances and cuts a plurality of wires arranged in the plurality of concave grooves while rotating the semiconductor crystal ingot having a plurality of concave grooves formed on the entire side surface.
A band portion for polishing a cut surface on the side surface of the plate-shaped body by moving the plate-shaped body arranged at each of the rear positions of the plurality of wires of the wire saw portion while swinging and advancing the plate-shaped body is provided.
The wire saw portion and the band portion are integrally composed of a pedestal for advancing the wire and a pedestal for advancing the plate-shaped body, so that cutting by the wire and polishing by the plate-shaped body are simultaneously promoted. It is characterized by that.

The semiconductor crystal wafer manufacturing apparatus of the second invention is an apparatus for executing the semiconductor crystal wafer manufacturing method of the first invention, and specifically, a pedestal for advancing a wire and a pedestal for advancing the plate-like body are integrated. By configuring the above, it is possible to realize simultaneous progress of cutting with a wire and polishing with a plate-shaped body.

As described above, according to the semiconductor crystal wafer manufacturing apparatus of the second invention, it is possible to easily and reliably manufacture a high-quality semiconductor crystal wafer.

The semiconductor crystal wafer manufacturing apparatus of the third invention is described in the second invention.
The wire saw portion and the band portion are arranged outside the wire around which the semiconductor crystal ingot circulates, and the wire and the plate-like body travel outward in the circumferential direction.

According to the semiconductor crystal wafer manufacturing apparatus of the third invention, the wire saw portion and the band portion are arranged outside the wire around which the semiconductor crystal ingot circulates, and the wire and the plate-like body are advanced outward in the circumferential direction. Therefore, high-precision cutting with a wire and polishing with a plate-shaped body can be concretely realized.

As described above, according to the semiconductor crystal wafer manufacturing apparatus of the third invention, it is possible to easily and reliably manufacture a high-quality semiconductor crystal wafer.

The semiconductor crystal wafer manufacturing apparatus of the fourth invention is described in the second invention.
The wire saw portion and the band portion are arranged inside the wire around which the semiconductor crystal ingot rotates, and the wire and the plate-like body advance inward in the circumferential direction.

According to the semiconductor crystal wafer manufacturing apparatus of the fourth invention, the wire saw portion and the band portion are arranged inside the wire around which the semiconductor crystal ingot circulates, and the wire and the plate-like body are advanced inward in the circumferential direction. Therefore, high-precision cutting with a wire and polishing with a plate-shaped body can be concretely realized.

As described above, according to the semiconductor crystal wafer manufacturing apparatus of the fourth invention, it is possible to easily and reliably manufacture a high-quality semiconductor crystal wafer.

The flowchart which shows the whole process of the manufacturing method of the SiC wafer (semiconductor crystal wafer) of this embodiment. It is explanatory drawing which shows the content of the groove processing process in the manufacturing method of the SiC wafer of FIG. It is explanatory drawing which shows the content of the cutting polishing process in the manufacturing method of the SiC wafer of FIG. It is explanatory drawing which shows the contents of the 1st surface processing process and the 2nd surface processing process in the manufacturing method of the SiC wafer of FIG. The explanatory view which shows the modification example of the cutting polishing process in the manufacturing method of the SiC wafer of FIG. The explanatory view which shows the other modification example of the cutting polishing process in the manufacturing method of the SiC wafer of FIG.

As shown in FIG. 1, in the present embodiment, the method for manufacturing a SiC wafer, which is a semiconductor crystal wafer, is to perform high-precision grinding on the surface of a wafer cut into slices from a SiC ingot ground into a cylindrical shape. A method for obtaining a SiC wafer, which is a groove processing step (STEP100 / FIG. 1), a cutting and polishing process (STEP200 / FIG. 1), a first surface processing step (STEP300 / FIG. 1), and a second surface processing step (STEP300 / FIG. 1). STEP400 / FIG. 1) is provided.

Details of each step will be described with reference to FIGS. 2 to 5.

First, in the groove processing step of STEP 100 shown in FIG. 2, a cylindrical SiC ingot 10 obtained by subjecting a pre-crystallized SiC crystal 1 to a cylindrical grinding process in which a crystal orientation is determined in the ingot processing step is prepared. do.

Then, in the grooving step of STEP 100, a plurality of concave grooves 11 are formed around the entire side surface of the SiC ingot 10.

Specifically, in the grooving process of STEP 100, the SiC ingot is rotated while rotating the grooving drum grindstone 20 having a plurality of convex portions 21 corresponding to the plurality of concave grooves 11 formed on the entire side surface on rotation axes parallel to each other. The concave groove 11 is formed by pressure contacting the 10.

It is desirable that the SiC ingot 10 (particularly the concave groove 11) obtained by the groove processing step is subjected to non-damage mirror surface processing by a chemical treatment method.

Next, in the cutting and polishing step of STEP 200 shown in FIG. 3, a plurality of wires 31 of the wire saw portion 30 which is a cutting processing device are arranged in the plurality of concave grooves 11 formed in the groove processing step of STEP 100, and the wires 31 are arranged. The SiC ingot 10 is cut into slices by advancing while orbiting the wire 31, and the plate-shaped body 41 of the band portion 40, which is a polishing device, arranged at each of the rear positions of the plurality of wires 31 is swung. The cut surface is polished on the side surface of the plate-shaped body 41 by advancing while cutting.

The semiconductor crystal wafer (SiC wafer) manufacturing apparatus (cutting and polishing apparatus) that realizes the cutting and polishing process of STEP200 includes a plurality of wires 31 with respect to the fixing member 32 that fixes both ends of the SiC ingot 10. Is provided at both ends of a wire saw portion 30 (wire saw device) for polishing a cut surface, and a plate-shaped body 41, which is provided at both ends of the plate-shaped body. It is provided with a band portion 40 (a device having a structure similar to that of a band saw device and not intended for cutting) having a swing mechanism 42 (for example, an actuator device or the like) for swinging the 41.

The wire saw portion 30 and the band portion 40 are configured to be slidable with respect to the fixing member 32 (the SiC ingot 10 and the fixing member 32 are fixed and do not move), and the frame is a pedestal for advancing the wire saw portion 30. Since the frames 34 and 35 and the frames 34 and 35, which are the pedestals for advancing the band portion 40, are commonly configured as one, cutting by the wire 31 and polishing by the plate-shaped body 41 proceed at the same time.

As a result, in the groove processing step of STEP 100, since a plurality of concave grooves 11 are formed in advance around the entire side surface of the SiC ingot 10, the SiC ingot 10 is connected by a plurality of wires 31 using the plurality of concave grooves 11 as guides. It can be cut into slices with high accuracy by circular processing.

Further, behind the plurality of wires 31 that are cut while rotating around the SiC ingot 10, a plurality of plate-like bodies 41 that are polished while swinging the cut surface are arranged, and the plurality of plates are arranged as the plurality of wires 31 progress. By advancing the shape 41, it is possible to polish and remove undulations and streaks at the same time as cutting by a single treatment, and it is possible to obtain a high-quality SiC wafer 100 with extremely high surface smoothness. It is possible , and there is no need to perform a chamfering process or a reference surface processing process with one surface as the reference surface on the cut surface.

Next, as shown in FIG. 4, in the first surface processing step of STEP 300, one surface 110 of one of the cut surfaces is used as a support surface, and the remaining other surface 120 is mechanically polished (high-precision grinding). Here, since the SiC ingot 10 obtained by the cutting and polishing step of STEP 200 has high smoothness on both of the two cut surfaces, any of the cut surfaces can be used as a support surface (reference surface). be.

Specifically, in the first surface processing step, grinding is performed by a mechanical polishing device 50 (ultra-high synthetic high-precision grinding device) that performs mechanical polishing.

The mechanical polishing device 50 includes a spindle 51 and a diamond grindstone 53 on a platen 52 which is a surface plate.

First, the other surface 120 is ground by the diamond grindstone 53 with the one surface 110 as the upper surface and the vacuum porous chuck 54 which is the suction plate of the spindle 51 sucking and supporting the other surface 120 as the lower surface.

At this time, the spindle 51 and the diamond grindstone 53 are rotationally driven by a drive device (not shown), and the spindle 51 is pressed against the diamond grindstone 53 by a compressor (not shown) or the like to grind the other surface 120.

After the grinding process, the diamond grindstone 53 may be dressed with a dresser or the like.

Further, the mechanical polish device 50 may have a functional water supply pipe so that a plurality of functional waters can be used at the time of processing, if necessary.

Next, in the second surface processing step of STEP 400, the other surface 120 that has been subjected to high-precision grinding by the first surface processing step is set as the upper surface, and the one surface 110 has the same high accuracy as the first surface processing step. Grind.

That is, the other surface 120 is used as the upper surface, and the vacuum porous chuck 54, which is the suction plate of the spindle 51, is attracted to the vacuum porous chuck 54, and the one surface 110 is used as the lower surface, and the one surface 110 is ground by the diamond grindstone 53.

In this case as well, dressing may be applied by pressing a dresser or the like against the diamond grindstone 53, if necessary.

According to the mechanical polishing (high-precision grinding) treatment of the first surface processing step of STEP300 and the second surface processing step of STEP400, either one of the transferless cut surfaces having high flatness obtained by the cutting and polishing step. By sequentially applying mechanical polish (high-precision grinding) to the remaining surface as a support surface (suction surface), so-called transfer can be prevented and a high-quality SiC wafer can be obtained, and the conventional surface can be obtained. It is possible to greatly simplify complicated manufacturing processes such as free grinding, that is, multiple laps of the first to fourth orders.

More specifically, it is not necessary to change the grindstone to perform rough grinding or finish grinding a plurality of times. Not only that, there is an advantage that the intrinsic semiconductor layer that can be used from the SiC wafer 100 can be largely secured.

In the high-precision grinding process of the first surface processing process of STEP300 and the second surface processing process of STEP400, the size of the SiC wafer 100 is currently up to 8 inches, and the wafer of each diameter depends on the area of the head. Is set and high precision grinding process (up to 12 inches is possible) is performed.

The above is the details of the method for manufacturing a SiC wafer according to this embodiment. As described in detail above, according to the method for manufacturing a SiC wafer according to the present embodiment, it is possible to easily and reliably manufacture a high-quality SiC wafer.

In the method for manufacturing a SiC wafer of the present embodiment, a chemical mechanical polishing (CMP) step or a wear cleaning step may be performed, if necessary, after the above-mentioned series of processes.

Further, in the present embodiment, a case where a SiC wafer is manufactured from a SiC ingot has been described as a method for manufacturing a semiconductor crystal wafer, but the semiconductor crystal is not limited to SiC, and the semiconductor crystal is not limited to SiC. Other compound semiconductors may be used.

Further, in the present embodiment, as shown in FIG. 3, the positional relationship between the wire saw portion 30 and the band portion 40 and the SiC ingot 10 is arranged inside the wire 31 around which the SiC ingot 10 circulates, and the wire 31 and the plate are arranged. The case where the shape 41 advances inward in the circumferential direction (upper side in the figure) has been described, but the present invention is not limited to this.

For example, as shown in FIG. 5, the positional relationship between the wire saw portion 30 and the band portion 40 and the SiC ingot 10 may be arranged outside the wire 31 around which the SiC ingot 10 orbits. In this case, the wire 31 and the plate-shaped body 41 proceed outward in the circumferential direction (lower side in the figure) to cut and polish the SiC ingot 10.

Further, for example, as shown in FIG. 6, the positional relationship between the wire saw portion 30 and the band portion 40 and the SiC ingot 10 may be arranged inside the wire 31 around which the SiC ingot 10 circulates. In this case, the wire 31 and the plate-shaped body 41 proceed inward in the circumferential direction (lower side in the figure) to cut and polish the SiC ingot 10.

Further, in the present embodiment, the case where all the plate-shaped bodies 41 of the band portion 40 are provided behind the plurality of wires 31 has been described, but the present invention is not limited thereto. For example, as shown in FIG. 6, the plate-shaped bodies 41 may be provided every other plate-shaped body 41.

In this case, the SiC wafer 100 obtained by cutting is a reference polished surface in which one of the two cut surfaces is polished by the plate-shaped body 41, and the other surface is unpolished by the plate-shaped body 41. It becomes a face. Therefore, in STEP 300, the reference polishing surface 110 is used as the upper surface, and the vacuum porous chuck 54, which is the suction plate of the spindle 51, is attracted and supported, and the other surface 120 on which the wire trace remains is used as the lower surface, and the other surface 120 is provided by the diamond grindstone 53. Grind. As a result, even when the number of the plurality of plate-shaped bodies 41 installed is halved to simplify the device configuration of the band portion 40, the mechanical polish device 50 can obtain a high-quality SiC wafer 100.

1 ... SiC crystal (semiconductor crystal), 10 ... SiC ingot (semiconductor crystal ingot), 11 ... concave groove, 20 ... grooved drum grindstone, 21 ... convex part, 30 ... wire saw part, 31 ... wire, 32 ... fixing member , 33 ... Wire saw bobbin, 34, 35 ... Frame (pedestal), 40 ... Band part, 41 ... Plate-like body, 42 ... Swing mechanism, 50 ... Mechanical polishing device (ultra-high synthetic high-precision grinding device), 51 ... Spindle, 52 ... Platen, 53 ... Diamond grindstone, 54 ... Vacuum porous chuck (suction plate), 100 ... SiC wafer (semiconductor crystal wafer), 110 ... One side, 120 ... Other side.

Claims (4)

A method for manufacturing a semiconductor crystal wafer, in which a wafer is cut into slices from a semiconductor crystal ingot ground into a cylindrical shape.
A grooving step of forming a plurality of concave grooves orbiting the entire side surface of the semiconductor crystal ingot, and
The semiconductor crystal ingot is cut into slices by advancing while rotating a plurality of wires arranged in the plurality of concave grooves formed in the groove processing step, and is arranged at each of the rear positions of the plurality of wires. The plate-shaped body is provided with a cutting and polishing step of polishing the cut surface on the side surface of the plate-shaped body by moving the plate-shaped body forward while swinging .
In the cutting and polishing step, the pedestal for advancing the wire and the pedestal for advancing the plate-shaped body are integrally configured, so that cutting by the wire and polishing by the plate-shaped body can proceed at the same time. A method for manufacturing a semiconductor crystal wafer. A semiconductor crystal wafer manufacturing device that cuts wafers into slices from a semiconductor crystal ingot that has been ground into a cylindrical shape.
A wire saw portion that advances and cuts a plurality of wires arranged in the plurality of concave grooves while rotating the semiconductor crystal ingot having a plurality of concave grooves formed on the entire side surface.
A band portion for polishing a cut surface on the side surface of the plate-shaped body by moving the plate-shaped body arranged at each of the rear positions of the plurality of wires of the wire saw portion while swinging and advancing the plate-shaped body is provided.
The wire saw portion and the band portion are integrally composed of a pedestal for advancing the wire and a pedestal for advancing the plate-shaped body, so that cutting by the wire and polishing by the plate-shaped body are simultaneously promoted. A semiconductor crystal wafer manufacturing device characterized by the above. In the semiconductor crystal wafer manufacturing apparatus according to claim 2,
The wire saw portion and the band portion are arranged outside the wire around which the semiconductor crystal ingot circulates, and the wire and the plate-like body travel outward in the circumferential direction of the semiconductor crystal wafer. Manufacturing equipment. In the semiconductor crystal wafer manufacturing apparatus according to claim 2,
The wire saw portion and the band portion are arranged inside the wire around which the semiconductor crystal ingot circulates, and the wire and the plate-like body advance inward in the circumferential direction of the semiconductor crystal wafer. Manufacturing equipment.

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