JPS61147521A - Method of coating chemical deposition layer on semiconductor substrate and reactor using therefor - Google Patents

Abstract

PURPOSE:To prevent a reactive product from accumulating on the inner wall of a reaction vessel by forming a heat beam transmitting partition plate between a heat source and the wall of the vessel, and providing cooling blowing means at both the heat source and vessel sides. CONSTITUTION:A partition plate 1 is formed of a material having excellent heat resistance and heat beam transmitting property, surrounded coaxially with a reaction vessel 101 in a tubular shape, mounted separately from the vessel 101 to partition between a heat source 102 and the vessel. One air flow 2 is interrupted by the plate 1 through the side of the source 102 externally of the source 102, and falls along the surface. The other air flow 12 is injected from above to a gap between the plate 1 and the side wall of the vessel 101 to fall.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a semiconductor substrate (hereinafter referred to as a semiconductor wafer).
The present invention relates to a method of applying a chemical vapor deposited layer to a reactor and a reactor used therein, and has particular application to improving cooling means for the reactor walls.

[Technical background of the invention]

A conventional method of vapor deposition for coating semiconductor wafers with chemical vapor deposited layers is illustrated by the reactor (hereinafter referred to as the apparatus) shown in FIG.

A semiconductor substrate 1, for example, a silicon m-crystal wafer (hereinafter abbreviated as semiconductor wafer) (104) is placed in a reaction vessel (10).
1) Place it on the support stand (103) inside. The inside of the reaction vessel was first filled with N2. After purging the air with an inert gas or the like, N2, which is one of the reaction gases, is supplied.

Next, a halogen lamp (102) as a heat source is turned on, and the semiconductor wafer (104) is heated by radiant heat transmitted through the side wall of the transparent quartz reaction vessel (103).

This temperature varies depending on the type of reaction gas used, but when using silicon halides such as 5iC14, 5iHC12, Si'82C12, it is 1050 to 1200°C.
Good.

Next, a reaction gas is introduced into the reaction vessel through the reaction gas inlet (101a). As a result, a gas phase reaction progresses near the surface of the heated semiconductor wafer, and a silicon single crystal is formed on the wafer.

Next, after the thickness of the single crystal layer reaches a desired value, the output of the heating source is stopped and the semiconductor wafer is guided into a cooling process. After cooling to a predetermined level, the inside of the reaction vessel is sufficiently purged with an inert gas such as N2, and one reaction vessel is opened and taken out to complete the vapor phase growth process.

During the pick-up process, especially during the heating stage, the temperature of the portion of the wall of the reaction vessel facing the lamp of the heat source tends to rise, even though it is a transparent body. There is a problem in that vapor-phase growth substances tend to be vapor-deposited, and when vapor-deposition occurs, the temperature of the chain portion increases, which impedes vapor-phase growth of semiconductor wafers. As a countermeasure to this problem, as described below, air was blown from the gap between the heating lamps to the wall of the reaction vessel to irradiate only radiant heat, but the temperature of the blown air also rose due to the heat generated by the heat source lamps and radiation plate. Therefore, an increase in the temperature of the reaction vessel wall was unavoidable.

Next, a conventional semiconductor vapor phase growth apparatus used in the pick-up method is illustrated in FIG. In the figure, reference numeral (101) denotes a reaction vessel, which is made of, for example, transparent quartz that is transparent to heat rays, and is surrounded by a reaction vessel that transmits heat radiated from a heat source (102) of a halogen lamp provided on the outer periphery. A heating base (103) made of carbon whose surface is coated with SiC is provided inside the reaction vessel, and semiconductor wafers (104, 104...) are arranged on the circumferential surface of the base (103), and the heating source (103) is
02) across the wall of the reaction vessel. In addition, the heating source (
Reference numeral 102) is actually a linear heating lamp equipped with a reflecting plate (112) opened on the opposite wall side of the reaction vessel.

Next, a semiconductor wafer (104°10
Formation of a vapor-phase growth film on 4...) is performed using a heating source (102).
The semiconductor wafer and the heating base (1
03) is heated to a predetermined temperature, the reaction vessel (1
A reactive gas, for example, a mixed gas of 5iC14, 112 and a doping gas, is introduced from the reactive gas inlet (101a) at the top of the semiconductor wafer (104, 104...
) is achieved by causing vapor phase growth near the surface of the semiconductor wafer, and the free silicon atoms are deposited on the semiconductor wafer.

In this vapor phase growth, the reaction vessel is made of a heat-transmitting material such as quartz, but the temperature rises due to long-term heating, and reaction products are deposited on the inner wall. In order to prevent this and further reduce the temperature rise of the heat source lamp case, reflector, etc., Equipped with high pressure air injection. As partially shown in a side view in FIG. 2(a) and in a plan view in FIG. 2(b), a downward air cooling flow and an air cooling flow passing through the gap between the heating sources are created.

In conventional vapor phase growth equipment, reaction products tend to accumulate on the inner walls of the reaction vessel, and when the amount of deposits increases, the quality of the vapor phase grown film deteriorates, and furthermore, the infrared rays from the heating source are absorbed, so the reaction There is a problem in that the heating efficiency of the semiconductor wafer itself inside the container is reduced. Therefore, in order to produce a vapor-phase grown film of stable quality, it was necessary to frequently clean the reaction vessel and wash off the reaction products deposited on the inner wall.6 [Object of the Invention] This invention solves the above-mentioned conventional problems. This method improves this point by preventing reaction products from accumulating on the inner wall of the reaction vessel and providing a stable vapor phase growth film.

[Summary of the invention]

In this invention, a heating source is placed on the outer periphery of a heat-transparent reaction vessel wall.
A semiconductor wafer is placed inside facing the heating source,
Regarding a method and apparatus for vapor phase growth of a semiconductor wafer, which performs vapor phase growth on a heated semiconductor wafer in a vapor phase growth atmosphere inside a container, and also applies forced air cooling to the case of a heat source and the wall of a reaction vessel during this heating, A heat ray-transparent partition plate is provided between the heat source and the reaction vessel wall, a ventilation means for cooling the heating source case is provided on the heat source side of the partition plate, and a cooling means for cooling the reaction vessel wall is provided on the reaction vessel wall side of the partition plate. The present invention is characterized in that it includes an air blowing means for coating a semiconductor wafer with a chemical vapor deposition layer.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings, regarding the differences from the conventional one. In addition, in the description, parts that are the same as the conventional ones are indicated by the same reference numerals in the drawings, and the description will be omitted.

One embodiment is shown in FIG. 1 in accordance with the conventional FIG. 2.

In the figure, (1) represents a heating source (102) and a reaction vessel (1).
01) is made of a material with excellent heat resistance and heat ray transparency, such as transparent quartz, and is tubular in shape and coaxially surrounding the reaction vessel (101). mounted apart.

and airflow using high-pressure air as a means of cooling air (
2, 12) consists of the following two systems.

First, one of the airflows (2) is the same as the conventional direction, from outside the heating source (102), passing through the side of this heating source, being blocked by the partition plate (1), and descending along this surface. formed by

Next, the other air flow (12) is formed by being injected from above into the gap between the partition plate (1) and the side wall of the reaction vessel (101) and descending.

Note that the air flow for the cooling described above may be provided in large numbers on the outside of this device using commonly used air supply pipes, and only some of them are shown in the figure, and the others are omitted.

As mentioned above, by separating the flow of the medium (air) for cooling the reaction vessel and the heating source, the medium for cooling the reaction vessel wall is not heated by the heat of the heating source, and the reaction vessel Only the walls can be efficiently cooled.

〔Effect of the invention〕

According to this invention, first, by making the flow of the cooling medium (air) between the wall of the reaction vessel and the heating source independent, cooling of the wall of the reaction vessel is improved, and the accumulation of reaction products on the inner wall of the reaction vessel is prevented. It could have been prevented.

As a result, 5it, which had previously been considered unusable due to the accumulation of reaction products in radiant heating equipment, was developed.
(4 gases can now be used as reaction gases. In addition, since deposition on the inner walls of the reaction vessel can be suppressed, frequent cleaning of the reaction vessel can be significantly reduced, allowing the production of vapor-grown films of stable quality over a long period of time. This greatly improved the operating rate of this equipment.

Note that the cooling medium is not limited to air; it goes without saying that the same effect can be obtained as long as it is a thermally stable gas that does not absorb radiation from the heating source.

[Brief explanation of drawings]

FIG. 1 shows a semiconductor vapor phase growth apparatus according to an embodiment of the present invention. (a) is a side cross-sectional view, FIG. (b) is a cross-sectional view taken along line AA in FIG. Figure (a) showing a semiconductor vapor phase growth apparatus is a side cross-sectional view, and figure (b) is a cross-sectional view taken along line AA in figure (a).

Claims (1)

Claims: 1. A semiconductor substrate to be coated on a susceptor that is opaque to radiant energy in a reaction chamber, at least a portion of whose walls are transparent to radiant energy transmitted at a predetermined short wavelength. and a radiant heat source is provided to transfer thermal energy at a predetermined wavelength to the semiconductor substrate by heating the susceptor through the reaction chamber wall, and the radiant heat source is provided between the radiant heat source and the reaction chamber wall to transfer heat to the semiconductor substrate by heating the susceptor through the reaction chamber wall. An energy-permeable partition plate is installed, and a gaseous reactant is introduced into the reaction chamber to contact the heated semiconductor substrate and cool the space between the partition plate, the reaction chamber wall, and the radiant heat source. A method for coating a semiconductor substrate with a chemical vapor deposited layer, the method comprising: forming a chemical vapor deposited layer only on the semiconductor substrate. 2. A radiant heat source that irradiates short-wavelength radiant energy, a reaction chamber that is placed close to the radiant heat source and houses the semiconductor substrate to be coated, and a reaction chamber that is provided in a portion of the wall of the reaction chamber that is close to the radiant source. a reaction chamber wall that is transparent to short wavelength thermal energy obtained by the heat source; a susceptor that is provided within the reaction chamber and supports the semiconductor substrate and is impermeable to the thermal energy; A reactor for coating a semiconductor substrate with a chemical vapor deposition layer, comprising: a partition plate transparent to the radiant heat energy disposed between the radiant heat sources.