JPH07120633B2 - Method for manufacturing jig for semiconductor - Google Patents

Description

The present invention relates to a method for manufacturing a jig for a semiconductor used in a heating furnace for heat treating a semiconductor, and more particularly to a diffusion furnace for manufacturing a semiconductor excellent in abrasion resistance. The present invention relates to a method of manufacturing a jig for a silicon carbide based semiconductor.

[Conventional technology]

In general, a furnace used for heat treatment of semiconductors includes a liner, a process tube attached to the liner and having a tapered end for introducing gas, a paddle or a carrier, and a wafer supporting material mounted thereon, that is, a semiconductor material mounting material. It consists of a mounting jig.

These components must not generate any dust-like contaminants. However, it is inevitable that these members will avoid shocking vibration during carry-out / carry-in operation, and micro-vibration during gas feeding or equipment, that is, friction and shock between the silicon wafer and these jigs. It is impossible to avoid such things. Therefore, these parts need not only mechanical strength but also wear resistance.

Materials satisfying these various conditions are limited, and among them, a silicon carbide sintered body is the most promising.

As a diffusion furnace made of such a silicon carbide sintered body,
Conventionally, it is disclosed in JP-A-51-85374 and JP-B-55-5852.

However, although many of these silicon carbide sintered bodies have been disclosed regarding the content of heavy metals such as alkali metals and copper contained in the material, that is, the purity, generation and prevention of dust due to corrosive wear or frictional wear is disclosed. There was no problem with the method, and there was the problem that a large amount of dust adhered to the silicon wafer and contaminated it.

[Problems to be solved by the invention]

The present invention provides a method for manufacturing a semiconductor jig for a semiconductor diffusion furnace in which the generation of dust caused by frictional wear as described above is extremely small.

[Means for solving problems]

The inventors of the present invention have conducted various studies on the above-mentioned carbon silicon-based material, and as a result, have newly found that the unevenness of the surface of the silicon carbide-based material greatly contributes to the wear property. By controlling the roughness, it was possible to extremely suppress the generation of dust, and a manufacturing method for processing the surface roughness of the member could be established, thus completing the present invention.

Next, the present invention will be described in detail.

The semiconductor jig of the present invention includes a process tube, a paddle having a size and shape that can be inserted into the process tube, a well-known carry-out / carry-in jig having a hook at a tip for putting the paddle in and out of the furnace core tube, Or a semiconductor mounting jig, Rm
The jig for a semiconductor is made of a silicon carbide material having a portion having a surface roughness of ax ≦ 15 μm.

Here, it is necessary to set the surface roughness of the semiconductor jig to Rmax ≦ 15 μm. When Rmax is larger than 15 μm, the friction resistance between the jig and the wafer or the jigs becomes extremely large, so that the wafer is scratched. This is because it tends to be worn or to generate abrasion powder, and among them, Rmax ≦ 10 μm gives more preferable results.

In order to achieve this Rmax ≦ 15 μm, each semiconductor jig must be polished with at least one kind of abrasive grain selected from diamond, silicon carbide, alumina, boron nitride, and cerium oxide having 100 # or more. is necessary. The reason for using abrasive grains with a grain size of 100 # or more is that if the abrasive grains that are coarser than 100 # are used, the roughness of the surface of the carbon siliconaceous material becomes large, and furthermore, the occurrence of microcracks due to processing occurs, This is because not only the strength is reduced, but also polishing powder or impurities penetrate into the microcracks to contaminate the wafer surface during use. Above all, 120
# It is more preferable to use a finer grain size abrasive grain.

It is necessary to use at least one selected from diamond, silicon carbide, alumina, boron nitride, boron carbide, and cerium oxide as the material of the abrasive grains. The reason is that the abrasive grains made of these materials can process the silicon carbide-based material quickly, and among them, diamond, boron nitride, silicon carbide, and boron carbide are the more effective abrasive grains. . In addition, as a method of using the abrasive grains, any of a metal bond, a resin bond-hardened one, and an electrodeposited and bonded form can be used. As the polishing method, conventional grinding and polishing methods can be used.

Further, as a grinding method, rough grinding may be performed in advance by using abrasive grains having a grain size larger than 100 #, and in that case, finishing must be performed using the abrasive grains having the grain size.

According to the present invention, the abrasive grains can also be used in a free state. In that case, since it is difficult to precisely finish the surface of the semiconductor jig with loose abrasive grains, it is preferable to use abrasive grains with a finer grain size as much as possible.
It is advantageous to use finer grain abrasives.

Next, examples of the present invention will be described in detail.

Example of Invention

96% by weight of the silicon carbide powder used as the starting material is β-type crystal, mainly contains 0.29% by weight of free carbon, 0.17% by weight of free silica, 0.3 ppm of iron and 3 ppm of aluminum, and has an average of 0.28 μm. It had a particle size.

5 parts by weight of polyvinyl alcohol and 300 parts by weight of water were added to 100 parts by weight of the silicon carbide powder, mixed in a ball mill for 5 hours and then dried.

A proper amount of this raw material was sampled and 50 mm with 15 mmφ and 4 holes
Two 100 × 10 mm square plates and four 15 mmφ × 500 mm round bars were prepared by rubber press molding. A slit was created on this round bar with a diamond cutter at a width of 0.8 mm and a pitch of 4.76 mm.

After this silicon carbide powder compact was sintered in a Tammann furnace at 1800 ° C., it was impregnated with phenol resin and heated again at 1600 ° C. in an inert atmosphere to carbonize the phenol resin. Next, this carbon-containing silicon carbide sintered body was assembled so that a 4-inch silicon wafer was placed thereon, and was immersed in molten silicon at 1800 ° C. to prepare a semiconductor material mounting jig made of a silicon carbide material. Excessive silicon is deposited on a part of this semiconductor material mounting jig, and each jig has a thickness of 6 μm.
As a result of processing with diamond abrasive grains having a grain size of, and abrasive grains of GC1500 #, a surface having a surface roughness as shown in FIGS. 1 and 2 was obtained.

〔The invention's effect〕

The effect of implementing the present invention is shown in FIG. This is the result of polishing the contact surface with the silicon wafer with GC1500 # abrasive grains or diamond abrasive grains (particle diameter 6 μmφ). For example, when a silicon wafer is mounted on a semiconductor jig made of a silicon carbide material impregnated with silicon as shown in FIG. 4, fine particles (particle size: 0.3 μm) adhered to the silicon wafer.
It is the result of measuring the number of φ or more). It can be seen that as compared with the case where the contact surface is not polished, GC1500 # abrasive grains, diamond abrasive grains (particle diameter 6 μmφ), and as the abrasive grains are made finer, fine particles attached to the silicon wafer are reduced.

As described above, the semiconductor jig, which is polished according to the present invention and is made of a silicon carbide material, can suppress the generation of dust against mechanical wear, and can improve the yield of semiconductor manufacturing and This is a jig that has an excellent effect of improving the characteristics.

Further, the silicon carbide based material of the present invention can be used for optical fiber manufacturing processes and silicon wafer pulling jig applications.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows diamond abrasive grains (particle size 6 μm in the example.
It is a graph which shows the measurement result of the surface roughness of the jig | tool for semiconductors which processed by (phi). FIG. 2 is a graph showing the measurement results of the surface roughness of the semiconductor jig according to the present invention, which was processed with GC1500 # abrasive grains in the examples. FIG. 3 shows a silicon wafer when the silicon wafer is actually placed on the semiconductor jig according to the present invention in which the contact surface with the silicon wafer is polished with GC1500 # abrasive grains or diamond abrasive grains (particle diameter 6 μmφ). Graph showing the results of measuring the number of fine particles (particle diameter 0.3 μmφ) attached to the
The figure is a perspective view showing a semiconductor jig and a silicon wafer adopted in this experiment.

Front Page Continuation (72) Kunihiko Wada Kunihiko Wada 1015 Kamiodanaka, Nakahara-ku, Kawasaki, Kanagawa Fujitsu Limited (72) Inventor Masakazu Furukawa 1-193, Kamiya Ogaki, Gifu Prefecture (72) Inventor Yokoyama Takao, 4-117-5, Motomaima, Ogaki, Gifu Prefecture (56) Reference JP-A-60-138915 (JP, A) JP-A-54-53962 (JP, A) JP-A-51-85374 (JP, A) ) Actual development Sho 63-1324 (JP, U)

Claims (2)

[Claims] 1. At least a part of a jig for semiconductors made of a silicon carbide based material, diamond, silicon carbide, alumina, boron nitride having a grain size smaller than 100 #,
Polished with at least one type of abrasive selected from boron carbide or cerium oxide to obtain surface roughness Rmax
A method for manufacturing a semiconductor jig, wherein ≦ 15 μm. 2. The semiconductor jig according to claim 1, wherein the semiconductor jig is a process pipe, a paddle having a size and shape that can be inserted into the process pipe, or a semiconductor material placement jig. Method of manufacturing ingredients.