JPS6043813A - Manufacture of silicon wafer - Google Patents

Abstract

PURPOSE:To obtain silicon wafers enabled to easily take out from a container and provided with a smooth surface by furthermore covering the container made of one or more kinds from among silicon nitride, boron nitride, and quarz with a powdery parting agent of said materials. CONSTITUTION:An internal wall surface of a container 1 made of one or more kinds from among silicon nitride, boron nitride, and quarz is covered with a powdery parting agent 3 made of materials of one or more kinds from among silicon nitride, boron nitride, and quarz. Next, silicon powder 2 is put in a concave body 1a surrounded by a high-frequency heating body 4 and a convex covering body 1b and the high-frequency heating body 4 are placed on the concave body 1a so as to engage the concave body with the convex covering body, to heat the silicon powder 2 in an argon atmosphere. The silicon powder 2 is fused by heat application and pressured by the self-weights of the convex body 1b and the upper high-frequency heating body 4 to form a thin disk. Polycrystalline silicon wafers are taken out of the container 1 after heat dissipation.

Description

[Detailed description of the invention] [Technical part of the invention] The present invention relates to a method for manufacturing silicon wafers.

[Technical background of the invention and its problems]

Silicon wafers are widely used in semiconductor devices, etc., and their field of use has recently expanded with the development of half-body packaging.

Conventionally, the CZ method (
A widely used method was to cut a silicon single crystal rod produced by QV (Czochralski method), FZ method (floating zone method), etc. into wafers. However, the silicon wafers obtained by this method are It takes a long time to produce a single crystal, and furthermore, it takes a long time to produce a single crystal.
- Since it requires work such as cutting very thinly (11), it has become extremely expensive on the market.

For this reason, recently? 6 W & 1rj from silicon, 4:
A method for manufacturing ribbon-shaped silicon wafers has been proposed.
l,ta.

In this method, in a vacuum or inert gas atmosphere, silicon melted in a container is injected from a slit-shaped nozzle onto a cooling body such as a roll that rotates at high speed, and is rapidly cooled on the surface of the roll to produce ribbon-shaped silicon wafers. ;This is to inform you. According to this method, the manufacturing speed of silicon wafers is dramatically high at 2 to 30 m/sec, and a poorly crystalline silicon wafer can be obtained, but the molten silicon is rapidly cooled on a curved surface such as a roll. Because of this, the resulting ribbon-like silicone material has the drawback that it is easily curved (it cannot be made with precision).

'Therefore, as a method for easily producing silicon wafers that are smooth, flat, and uncurved, silicon powder is placed in a container made of silicon carbide with a smooth inner wall, and the silicon powder is melted in a bath using a high-frequency heater. Later, a method was proposed in which the silicone wafer was cooled and removed from the container.

In this method, the silicon wafer is in contact with the smooth inner wall surface of the container, and there is almost no shaking during manufacturing, so the polycrystalline silicon wafer is flat with no curves and has a precisely uniform thickness. It is possible to manufacture wafers.

However, this method has the disadvantage that when the obtained silicone wafer 7J is brought into contact with the container and taken out, the silicone wafer 1- is not peeled off from the container. Therefore, in order to eliminate this problem, a method of manufacturing silicon urethane by applying a powdered release agent of ``recon nitride'' to the inner wall surface of a container made of silicon carbide was considered. - Peeling from the container was incomplete, and the above defects could not be eliminated.

[Purpose of the invention]

The present invention was made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a method for easily manufacturing silicone material with a smooth surface by improving the peelability between a heat-resistant container and silicone material. shall be.

[Summary of the invention]

The present invention is a container equipped with a concave body and a lid, and which is made of at least silicon nitride, boron nitride, and quartz. After coating with a powdered mold release agent consisting of at least one of silicone powder and quartz, the silicon powder is heated and melted in a vacuum or an inert gas atmosphere in the container, and is made into a wafer shape under the pressure of six bodies and cooled. 1) A method of manufacturing a condensed wafer.

In this way, silicon nitride, boron nitride,
One container made of at least one type of quartz is coated with a powdered mold release agent of the above material.

The peelability between the container and the silicon wafer is good, and there is almost no adhesion (the silicon wafer can be easily taken out from the container, and a silicon wafer with a smooth surface can be manufactured).

[Embodiments of the invention]

The manufacturing method of the present invention will be explained based on examples and figures.

The figure shows a cross-sectional view of the main parts of the manufacturing equipment used in the present invention. The container (1) has a flat cylindrical shape, and a concave body (1a) into which silicon powder (2) is placed. ) (inner diameter 50mm, groove width 2Qmrr+, wall thickness 3mm).

A convex lid body (
lb) (Outer diameter of the protrusion 49mm, height of the protrusion 19.5m
m) and (rusted Az). This concave body (1a)
The depth and inner diameter of the groove are slightly thicker than the height and outer diameter of the convex part of the convex lid body (1,b).
The dimensions are such that a slight gap is created between the concave portion and the convex portion when the two are fitted together. This container (1) contains silicon nitride and boron nitride.

Consists of at least one type of quartz. however,
The entire container (1) does not necessarily need to be made of only the above-mentioned material, but only a small portion of the container (2) that fits into the unevenness may be covered with the above-mentioned material.

The concave body (1a) and the convex lid body (''b) may be made of different materials. X3) A layer of powdered mold release agent made of at least one material selected from silicon nitride, boron nitride, and quartz.

In addition, (4) is a high frequency heating element, and a high frequency coil (5
) generates heat.

First, coat the inner wall of the container (1) with silicon nitride.

It is coated with a powdered mold release agent (3) consisting of a small amount of boron nitride and quartz, and has a thickness of 50 μm.
Separate the Oj layer. This layer is powdered mold release agent (3)
This is done by mixing with a volatile Aiso common agent and applying this mixed solution. Here, powdery τ[f, molding agent (3)
The average particle size of 50μmη or less is inevitable, but 5~
It is more desirable if it is 20 μm or less. Next, 2.0 g of silicon powder (2) is put into the concave body (1a) around which the high frequency heating element (4) is arranged, and the four parts and the convex part are fitted onto the concave body (1a). Place the convex lid (ib) and the high-frequency heating element (4) on it. A high frequency heating element (4) is caused to generate heat by a high frequency coil (5), and the silicon powder (2) is heated at 1550° C. for 3 minutes in an argon atmosphere.

At this time, the silicon powder (2) becomes an M-molten state by heating, and the convex mold body (1b) and the upper high frequency heating element (
4) It is pressurized by its own weight and becomes a small disk shape.

After cooling, a polycrystalline silicon wafer with a diameter of 59 mm and a thickness of 0.3 mm is taken out from the container (1) to obtain a silicon wafer.

As described above, the tea utensil (1) and the powdered P1. Molding agent (3) 0) &11 Proceed from silicon nitride, boron nitride, and quartz, respectively, and obtain the above σ)>'
A silicon wafer is manufactured using the L manufacturing method, and a container (1
) and peeling of silicon wafer 7 18I 5),? Beta.

The results are shown in the table. For comparison, results for other material combinations are also shown. From the Hirohaku table below, the material of container (1) is silicon nitride.

Select from boron nitride or quartz, and apply a powdered mold release agent (3) made of the above material to the inner wall surface of the container (1) to form a silicon wafer, and then remove the silicon wafer from the container (1). It was found that the removability was good and that it could be easily pivoted without any accidents such as breakage. Moreover, the obtained silicon wafer had a smooth surface and no curves (although it was a precision one).

〔Effect of the invention〕

According to the manufacturing method of the present invention, silicon powder can be easily taken out from a container, and silicon wafers with smooth and precise surfaces can be easily manufactured.

This shows a first fold view.

DESCRIPTION OF SYMBOLS 1... Container, 1a... Concave body, 1b... Convex lid, 2... Silicon powder, 3... Powdered mold release agent, 4
...High frequency heating element, 5...High frequency coil.

Claims (1)

[Scope of Claims] A container comprising a concave bottle and a lid, which is silicon nitride or boron nitride. The inner wall of the container is made of quartz (also known as -41),
Silicon nitride, boron nitride. quartz is coated with a powdered mold release agent consisting of
A method for manufacturing a silicon wafer, which comprises heating and melting the silicon powder in the container in a vacuum or an inert gas atmosphere, and forming it into a wafer shape by applying pressure from a lid.