JPS5950093A - Diffusion furnace type vacuum vapor growth device - Google Patents

Abstract

PURPOSE:To enable the uniform heating of samples with good thermal efficiency by heating the samples, many of which are arranged by a susceptor, by the heat evolved with the inner tube enclosing the circumference of the samples in a reaction vessel. CONSTITUTION:A cover 2 is opened and a susceptor 5 arranged with samples 6 is set in an inner tube 4, then the cover 2 is closed and a purging gas is supplied to expel the air and high frequency electric power is supplied to a work coil 9. The tube 4 is induction-heated to evolve heat, thereby heating the samples 6. Since the tube 4 is tubular, the radiation heat repeats reflections and heats efficiently and uniformly the samples. Cooling water is made run in a cooling pipe 8 to suppress the temp. elevation around the reactor 1. When the samples 6 attain to a prescribed temp., a reacting gas is supplied from a nozzle 7 to grow an epitaxial layer on the surfaces of the samples 6. Since the samples 6 are uniformly heated, the epitaxial layer having a uniform thickness is formed without variance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vapor phase growth apparatus, and particularly employs a so-called diffusion furnace type in which a large number of samples are placed vertically at relatively small intervals within a cylindrical reactor. The present invention relates to a vapor phase growth apparatus.

Conventionally, three types of vapor phase growth equipment have been generally used: vertical, horizontal, and barrel types, but these types are structurally capable of processing only a small number of wafers at a time, and the increase in the number of wafers that can be processed at one time has now reached its limit. As a result, there is an urgent need to develop new diffusion furnace type and in-line type equipment.

However, in the case of a diffusion furnace type apparatus, lamp heating methods, induction heating methods, and the like are conceivable as heating methods using a cold wall, but most of them are insufficient in terms of heat uniformity and thermal efficiency.

The purpose of the present invention is to more evenly heat the samples arranged perpendicularly to the reaction vessel in order to measure the uniformity of the epitaxial layer within one sample and between each sample, and also to improve thermal efficiency. An object of the present invention is to provide a diffusion furnace type reduced pressure vapor phase growth apparatus which allows

To achieve this object, the present invention includes a cylindrical reaction vessel, an inner chive that serves as a heat source provided in the reaction vessel, and a sample placed in the inner chive along the longitudinal direction of the inner chive. a susceptor held perpendicular to the direction; a heat source provided on the outer periphery of the reaction vessel for heating the inner cheek by induction heating or lamp heating; and a susceptor for supplying gas to the reaction vessel. A supply/discharge means is provided, and a large number of samples arranged at relatively small intervals by the susceptor are heated by heat generated by an inner tube surrounding the samples in the reaction vessel. This allows the sample to be heated uniformly and thermally efficiently.

FIG. 1 showing one embodiment of the present invention will be described below.

Reference numeral 1 denotes a reaction vessel, which is made of an insulating material such as quartz, and has a lid 2 that can be opened and closed at the right end in the figure, and an exhaust port 3 at the left end.

Inside the reaction vessel 1, an inner tube 4 is provided almost concentrically. This inner tube 4 is made of a conductive material such as graphite. A susceptor 5 is provided within the inner tube 4.

This susceptor 5 positions the samples 6 perpendicularly to the longitudinal direction of the inner tube 4, and arranges a large number of samples 6 at relatively small intervals as shown in the figure, similar to a diffusion furnace. ing. A nozzle 7 is inserted near the right end of the reaction vessel 1 in FIG.

A cooling pipe 8 is provided on the outer periphery of the reaction vessel 1, and
A high frequency induction heating coil (hereinafter referred to as a work coil) 9, which is a heating source for inductively heating the inner cheek 4, is wound around the outside thereof. Further, on the outer surface (or the inner surface may be used) of the reaction vessel 1, an M
An insulating reflective film 10 having good infrared light reflectance, such as gO, is provided.

Next, the operation of this device will be explained. Open the lid 2,
The susceptor 5 with the samples 6 arranged as shown in the figure is set in the inner chest 4, and the lid 2 is closed. Next, while exhausting from the exhaust port 3, purge gas is supplied from the nozzle 7 to exhaust the air, and high frequency power is supplied to the work coil 9, thereby starting a series of operations for vapor phase growth.

By supplying power to the work coil 9, the inner tube 4 is heated by induction and generates heat. The sample 6 is heated by the heat generated by the inner tube 40. At this time, since the inner tube 4 has a tube shape as its name suggests, the radiant heat directed to the inside is repeatedly reflected within the inner tube 4, heating the inside of the inner tube 4 efficiently and uniformly. It also acts effectively on the sample 6. The radiant heat directed outward from the inner chest 4 is transferred to the reflective film 10.
Since the light is reflected by the light and returned into the reaction vessel i, it prevents the outside temperature from rising and acts more effectively on the sample 6.

Note that cooling water is allowed to flow through the cooling pipe 8 at the same time as the power is supplied to the work coil 9, thereby suppressing the rise in temperature around the work coil 9 and the reaction vessel 1 to a lower level.

When the sample 6 reaches a predetermined temperature, a reaction gas is supplied from the nozzle 7 into the reaction vessel 1 to form an epitaxial layer on the surface of the sample 6. At this time, since each sample 6 is heated uniformly as described above, each sample 6
It is possible to suppress variations between samples 6 and thickness unevenness within each sample 6, thereby forming an epitaxial layer with a more uniform thickness. Note that the exhaust gas after the reaction and the unreacted reaction gas are exhausted from the exhaust port 3.

FIG. 2 shows another embodiment of the present invention, in which a large number of holes (including slits) 11 are provided in the inner tube 4, and reaction gas and the like flow into the inner tube 4 through these holes 11. In this way, the concentration of the reactant gas supplied to the surface of each sample 6 can be made more uniform.

Further, the nozzle 7 is provided so as to span almost the entire length of the space between the reaction vessel 1 and the inner cheek 4, and an appropriate number of nozzle holes 12 provided along the longitudinal direction of the nozzle 7 are provided along the longitudinal direction of the space. The reactant gas is supplied uniformly over almost the entire direction. Furthermore, a buffer 13 made of quartz or the like is provided at the end of the space between the reaction vessel 1 and the inner cheek 4 on the exhaust port 3 side, and a buffer 13 made of quartz or the like is provided to direct the reaction from the inside of the space to the exhaust port 3. This prevents gas from flowing directly.

Note that this buffer 13 is preferably formed so that when purge gas is supplied from the nozzle 7, the gas in the space is more completely replaced with the purge gas, so that the buffer 13 is not completely blocked but allows some gas to pass through.

FIG. 3 shows still another embodiment of the present invention, in which a gas flow control cheep 14 is provided on the outside of the inner tube 4, and an appropriate cross-sectional area is formed on the outer circumference of the inner cheep 4 by both of them. An annular gas flow path 15 is formed, and a nozzle 7 supplies the reaction gas to the gas flow path 15 so that the reaction gas can more uniformly flow in from the hole 11. An infrared lamp 16 is used instead of the work coil 9. 17 is an infrared light reflecting plate. In this case, the reaction vessel 1 and the gas flow control cheep 14 are made of a material that transmits infrared light, such as quartz, and the inner chive 4 is made of a material that absorbs infrared light and generates heat, such as graphite. It is necessary to form, Figures 1 and 2
The reflective film 10 shown in the figure is unnecessary, and an infrared light reflecting plate 17 takes its place.

Further, the cooling means such as the cooling pipe 8 may be provided outside the infrared light reflecting plate 17 as shown in the figure.

As described above, according to the present invention, more samples can be heated uniformly, and thereby more uniform vapor phase growth can be performed on many samples.

[Brief explanation of the drawing]

1 to 3 are schematic vertical sectional views showing different embodiments of the present invention. DESCRIPTION OF SYMBOLS 1... Reaction container, 2... Lid, 3... Exhaust port, 4... Inner tube 5... Susceptor,
6... Sample, 7... Nozzle, 10... Reflective film, II... Hole, 12... Nozzle hole, I3...
・Buffer, 14・ ・Cheap for gas flow control, 1
5. Gas flow path, 16. Infrared light lamp (heating source), 17. Infrared light reflection plate. Applicant: Toshiba Machine Co., Ltd.9-

Claims (1)

[Claims] 1. A cylindrical reaction vessel, an inner tube that serves as a heat source provided in the reaction vessel, and a sample disposed within the inner chest and arranged perpendicularly to the longitudinal direction of the inner cheek. A diffusion furnace type reduced pressure vapor phase growth apparatus comprising: a susceptor positioned and held in the reaction vessel; an inner tube heating source provided on the outer periphery of the reaction vessel; and means for supplying and discharging gas to and from the reaction vessel. 26. The diffusion furnace type reduced pressure gas phase according to claim 1, wherein the reaction vessel is made of an insulating material, the inner tube is made of a conductive material, and the inner tube heating source is a high-frequency induction heating coil. growth equipment. 3. Claim 1, wherein the reaction vessel is made of a material that transmits infrared light, the inner tube is made of a material that absorbs infrared light, and the inner tube heating source is an infrared lamp. The diffusion furnace type reduced pressure vapor phase growth apparatus described above. 4. Claim 1 or 2 in which the reaction container is treated to improve infrared light reflectance toward the inside thereof.
Diffusion furnace type reduced pressure vapor phase growth apparatus as described in . 5. Claim 1.2 or 4, wherein the reaction vessel is coolable by a cooling means provided on the outside thereof.
Diffusion furnace type reduced pressure vapor phase growth apparatus as described in . 6. The diffusion furnace type reduced pressure gas according to any one of claims 1 to 5, wherein the inner tube has a large number of holes, and gas flows into the inner tube through the holes. Phase growth device. 7 Claim 1 in which the gas discharge side between the reaction vessel and the inner tube is closed almost entirely
7. The diffusion furnace type reduced pressure vapor phase growth apparatus according to any one of items 6 to 6. 8. The diffusion furnace-type reduced pressure vapor phase growth apparatus according to any one of claims 1 to 7, wherein a gas flow control Cheap is interposed between the inner Cheap and the reaction vessel. .