JPS6070720A - Manufacturing device of silicon thin body - Google Patents

Abstract

PURPOSE:To enable to manufacture a smooth silicon thin body having no curve and no unevenness by a method wherein a rotating board having the surface covered with silicon carbide is used. CONSTITUTION:A silicon thin body manufacturing device is constructed of a quartz heat resistant vessel 3 furnished with a nozzle 1 of 10mm. slit width, and to project molten silicon 2 according to gas pressure of inactive gas, a high-frequency heating coil 4 arranged on the outside periphery of the heat resistant vessel 3 thereof, and to melt silicon raw material powder in the heat resistant vessel 3 thereof, and a rotating board 6 performed covering of silicon carbide 5 extending over several ten mum on the surface to come in contact with molten silicon 2, and the device thereof is furnished in inactive gas or in a vacuum. Covering of the silicon carbide 5 is performed according to usual application and bake, vapor phase growth, etc. When the device thereof is used, the projected molten silicon 2 is formed in the disk type of 0.3mm. thickness and 50mm. diameter by centrifugal force of the rotating board 6, and when it is removed from the rotating board 6 after cooled, a silicon thin body 7 of smooth and having uniform thickness can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Techniques of the Invention) The present invention relates to two suitable manufacturing apparatuses for manufacturing thin silicon bodies.

[Technical background of the invention and its problems]

Silicon thin bodies are widely used in semiconductor devices.

Conventionally, the CZ method (
Czochralski &), FZ method (Floating Zone method) etc.
The two-cut method was widely used.

However, the silicon wafer obtained by this method is extremely expensive because it takes two hours to grow a silicon single crystal.Also, the silicon wafer obtained by this method is extremely expensive because it takes two hours to grow a silicon single crystal. Although there is a manufacturing method, it takes a long time to grow the crystal of a ribbon-shaped silicon thin body, and the growth speed of the silicon thin body is low, which has the same drawbacks as above.

As a means to solve this problem, ribbon-shaped thin silicon bodies are manufactured from molten silicon at high speed in Japanese Patent Application Laid-open Nos. 53-3973, 55-52218, 136548-1980, and 136549-1989. A method has been proposed. For example, in a vacuum or inert gas atmosphere,
The silicon, which is in a molten state in a heat-resistant container made of stone, etc., is injected from a slit-shaped nozzle under the pressure of an inert gas introduced into the heat-resistant container (2). Rotating cooling body (e.g. copper roll)
A ribbon-like silicon thin body is produced by rapid cooling. According to this method, the silicon thin body can be obtained at a manufacturing speed of 2 to 30 m/sec, so it has the advantage of being manufactured in a short time, but since the rolls rotating at high speed are curved at a predetermined curvature The ribbon-shaped silicon thin body produced by contacting this roll also curved in a manner similar to the curvature of the roll, making it difficult to obtain a flat silicon thin body.

In addition, the silicon raw material is placed in a heat-resistant container, melted by a high-frequency heating coil (secondary), and the molten silicon is injected into the center of a rotating disk rotating at high speed (-), and heated by the centrifugal force of this rotating disk. A method was proposed for manufacturing thin silicon bodies by forming them into thin disk shapes.According to this method, the production rate of silicon thin bodies does not depend on the production rate of silicon single crystals (2), so it is extremely difficult to produce silicon thin bodies (2). Moreover, since the process is carried out on a smooth rotary disk, it is possible to easily produce a thin silicon body with a smooth surface and no curvature.

However, the rotary disk used in this method is made of copper or graphite. The surface had many irregularities and was not smooth.Also, in the case of a rotating disk made of graphite (=, the wettability with molten silicon was better than that of copper, but the molten silicon was cooled and solidified. The resulting silicon thin body adhered strongly ('-) to the surface of the rotary disk, and the second disadvantage was that the graphite and silicon on this surface caused a chemical reaction and bonded together. For this reason, when the obtained silicon thin body is removed from the surface of the rotating disk (the surface of the silicon thin body (9) where two unevennesses have occurred, in the steepest case (= the thin body is damaged, and the rotating vibration surface ( = Moisture was generated, and the lifespan was shortened (two problems also occurred).

[Purpose of the invention]

The present invention has been made to eliminate the above-mentioned drawbacks.
It is an object of the present invention to provide a silicon wafer manufacturing apparatus that easily manufactures silicon waes that are not curved and have extremely smooth surfaces.

[Summary of the invention]

a heat-resistant container provided with a nozzle for injecting molten silicon; a heater disposed around the heat-resistant container to melt the silicon in the heat-resistant container; 7 Recon thin body manufacturing apparatus equipped with a rotary disk for spreading and quenching silicon to obtain a silicon thin body.

An apparatus for producing a silicon thin body having such a configuration (Secondly, the molten silicon injected from the nozzle is heated to a rotating vibrating surface (preferably at the center of rotation) whose surface is made of silicon carbide (-
During injection, it was simultaneously spread and quenched by the high-speed rotation of this rotary disk (two-speed centrifugal force) to produce a disk-shaped silicon thin body with a smooth and uniform thickness.

[Embodiments of the invention]

The details of the present invention will be explained below based on two embodiments and drawings.

The drawing shows a silicon thin body manufacturing apparatus according to an embodiment of the present invention, and the slit width is 10InT! A quartz heat-resistant container (3) equipped with an L nozzle (1) and injecting molten silicon (2) by inert gas pressure, and a west F1 valve around the outer periphery of the heat-resistant container (3), - Natsu in 1ffl left of Otsu's Resistance)
A high-frequency heating coil (4) melts the molten silicone (4), and a rotary disk (6) whose surface in contact with the molten silicon (2) is coated with silicon carbide (5) to a thickness of several tens of micrometers (2.
). The coating with silicon carbide (5) is carried out by conventional coating and baking methods, vapor phase growth, etc.

Using this manufacturing device, a silicon thin body (force) was manufactured as follows (2). First, silicon raw material powder was placed in a heat-resistant container (3), and
Melt the molten silicon (2) in a bath at 50°C and transfer it to the gas pressure of the inert gas (from the two-way nozzle (1) at a rotating speed of 100 to 250 rPm) in an inert gas or vacuum. The central part of (6) (= injected. The injected molten silicon (2) is affected by the centrifugal force ('-) of the rotary disk (6) in the form of a disk (2-shaped) with thickness Q, 3 mrn and diameter 5Q mx. After cooling, it was removed from the rotary disk (6) to obtain a thin silicone body having a smooth and uniform thickness.

In contrast, the following (2) For comparison, the rotary disk (6) not coated with silicon carbide was made of copper, iron, stainless steel, or graphite, and a silicon thin body was coated under the same conditions as above. The results are summarized in the table below.

According to the results shown in the table, by using a rotating disk whose surface was coated with silicon carbide, it was possible to produce a smooth silicon thin body with no curvature or unevenness. can be easily removed from the
The surface of the rotary disk is not scratched, and therefore the durability of the rotary disk can be significantly improved.

〔Effect of the invention〕

Silicon thin body manufacturing apparatus of the present invention (according to -, curved.

It is possible to produce a thin silicon body with no unevenness, smoothness, and uniform thickness in a short time, and the need for frequent replacement of the rotary disk of the device is also drastically reduced.

[Brief explanation of drawings]

The drawing shows a cutaway sectional view of main parts of the silicon thin body manufacturing apparatus according to the present invention (1). ■ Nozzle, 2: Molten silicon, 3: Heat-resistant container,
4: High frequency heating coil, 5: Silicon carbide coating layer, 6: Rotating disk.

Claims (1)

[Claims] a heat-resistant container provided with a nozzle for injecting molten silicon; a heater for melting the silicon in the heat-resistant container; and a heater having at least a surface made of silicon carbide; 1. An apparatus for producing a thin silicon body, comprising a rotary disk for spreading and rapidly cooling silicon to obtain a thin silicon body.