JPH02192118A - Optical vapor growth method - Google Patents

Abstract

PURPOSE:To prevent contamination of the light-transmitting wall of the reaction container located close to a light source by a method wherein a light- transmitting plate is placed along the inner wall of the reaction container at the point crossing a susceptor and the light source. CONSTITUTION:A light-transmitting plate 12 of quartz and the like, which is sufficiently wider and longer than a substrate 3, is placed on the upstream side along the inner wall of a reaction container 1 at the position crossing a susceptor 2 and a light source 6 for optical reaction. As the part on the upstream side of the light-transmitting plate 12 is shielded by a partition plate 7, raw-gas grown substance is hardly adhered. Accordingly, as the raw gas grown substance is adhered to the light-transmitting plate 12, the contamination of the light-transmitting wall part of the reaction container can be prevented. Also, the contaminated part of the light-transmitting plate is moved, and an uncontaminated part is positioned on the light-transmitting wall part, and the reproducibility of optical vapor growth can be improved without aggravating light-transmitting property.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical vapor phase growth method for performing vapor phase growth using light.

Prior Art] As shown in FIG. 3, in the conventional photo-vapor phase growth method, a substrate 3 is supported on a susceptor 2 in a translucent reaction vessel 1 made of quartz, and the susceptor in the reaction vessel 1 is A raw material gas is supplied to the susceptor 2 side from a raw material gas inlet 4, and a purge gas is supplied in the same direction as the raw material gas from a purge gas inlet 5 to the side remote from the susceptor 2. 8
This was carried out by irradiating the substrate 3 on the susceptor 2 with light in the direction 1 from the 16 to cause the substrate 3 to undergo photovapor phase growth.

Note that 7 is a partition plate located between the raw material gas inlet 4 and the purge gas inlet 5 in the reaction vessel 1, and the upstream side of the reaction vessel 1 is separated from the reaction chamber by the partition plate 7. 8
and a purge chamber 9. 10 is a susceptor drive shaft for driving the susceptor 2.

“Problems to be solved by the invention” However, in such conventional photo-vapor phase growth methods,
When the humidity of the susceptor 2 is increased and photovapor phase growth is performed, natural convection occurs as the susceptor 2 heats up, promoting mixing of the raw material gas and the purge gas. There was a problem in that the light-transmitting wall portion 11 became dirty due to adhesion of products of the raw material gas, resulting in poor light transmittance and poor reproducibility of optical vapor phase growth. In order to improve this problem, it is necessary to wash the reaction vessel 1 frequently, which has the problem of lowering the operating rate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photo-vapor phase growth method that can prevent staining of the light-transmitting wall of a reaction vessel near the light source.

[Means for Solving the Problems] To explain in detail the present invention for achieving the above object, the present invention includes a method in which a substrate is supported by a susceptor in a reaction vessel, and a raw material gas is supplied into the reaction vessel. , in a photovapor phase growth method in which light is irradiated from a photoreaction light source outside the reaction vessel toward the substrate on the susceptor to perform photovapor phase growth on the substrate, the width of the substrate is wider than the substrate. A light transmitting plate having a length of is moved so that it is present on the susceptor.

[Operation] By doing this, the raw material gas product adheres to the light-transmitting plate, so it is possible to prevent the light-transmitting wall portion of the reaction vessel from becoming dirty. The dirty part of the light-transmitting plate is moved, so the clean part is located on the light-transmitting wall, and the light-transmitting properties are not deteriorated.
The reproducibility of optical vapor phase growth can be improved.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. Note that parts corresponding to those in FIG. 3 described above are shown with the same reference numerals.

FIG. 1 shows a first embodiment of the present invention. In this embodiment, a transparent plate 12 such as a quartz plate having a width sufficiently wider than the substrate 3 and a required length is attached to the inner wall of the reaction vessel 1 at a position crossing between the susceptor 2 and the light source 6 for photoreaction. Place it on the upstream side. Since the upstream portion of the transparent plate 12 is shielded by the partition plate 7, raw material gas products are less likely to adhere thereto. In the photovapor phase growth, a source gas (for example, S!H4 with H2 as a carrier gas) is flowed into the reaction chamber 8, a purge gas (for example, H2) is flowed into the purge chamber 9, and Si is deposited on the surface.
C]-treated carbon susceptor 2 is heated with a heater (not shown) outside the reaction vessel 1 (for example, an induction heater or a lamp heater), and when it reaches a predetermined temperature, a light source for photoreaction (for example, This is done by irradiating ultraviolet light from a high-pressure mercury lamp) 6.

At this time, the light-transmitting plate 12 is moved downstream as the optical vapor phase growth progresses by operating the light-transmitting plate moving shaft 13. The moving speed of the light-transmitting plate 12 is such that the light transmittance does not fall below a certain level due to the attachment of raw material gas products to the light-transmitting plate 12. Further, the length of the light-transmitting plate 12 is set so that it does not come off from the light-transmitting wall portion 11 even after one cycle of photo-vapor phase growth is completed.

After one cycle of photo-vapor phase growth is completed, the transparent plate 12 is replaced with a clean one. The dirty transparent plate 12 is cleaned and used for the next use.

Note that the movement of the light-transmitting plate 12 may be performed after one photo-vapor phase growth process is completed so that the clean portion is located on the susceptor 2 during the next vapor-phase growth process.

[Effects of the Invention] As explained above, according to the optical vapor phase growth method according to the present invention, the products of the raw material gas adhere to the light-transmitting plate, so that staining of the light-transmitting wall portion of the reaction vessel can be prevented.

In addition, since the dirty part of the light-transmitting plate is moved, the clean part is located on the light-transmitting wall, which prevents deterioration of light transmission and facilitates photo-vapor phase growth with good reproducibility. can be set. Furthermore, according to this method, the number of times the reaction vessel is washed can be significantly reduced.

[Brief explanation of the drawing]

1 and 2 show the first part of a photo-vapor phase growth apparatus for carrying out the method of the present invention. A vertical cross-sectional view of the second embodiment, and FIG. 3 are vertical cross-sectional views of a conventional optical vapor phase growth apparatus. 1... Reaction container, 2... Susceptor, 3... Substrate,
4... Raw material gas inlet, 5... Purge gas inlet,
6... Light source for photoreaction, 7... Partition plate, 8... Reaction chamber, 9... Purge chamber, 10... Susceptor drive shaft, 1
DESCRIPTION OF SYMBOLS 1... Transparent wall part, 12... Transparent plate, 13... Transparent plate movement axis.

Claims (1)

[Claims] A substrate is supported by a susceptor in a reaction container, a raw material gas is supplied into the reaction container, and light is irradiated from a light source for photoreaction outside the reaction container toward the substrate on the susceptor to support the substrate. In the photo-vapor phase growth method, a light-transmitting plate having a width wider than the substrate and a required length is placed along the inner wall of the reaction vessel at a position crossing between the susceptor and the light source. A method for optical vapor phase growth, characterized in that the transparent plate is moved so that a dirty part of the transparent plate is separated from the top of the susceptor and a clean part of the transparent plate is placed on the susceptor.