JPS61166125A - Organic metal vapor-phase growing method - Google Patents

Abstract

PURPOSE:To enable to remove the intermediate reaction induced when the temperature of PH3 rises by a method wherein the PH3 is decomposed by photochemical reaction without heating the PH3. CONSTITUTION:As PH3 absorbs the light of 200-220nm, the PH3 can be decomposed without generating temperature rise when a photochemical reaction is performed utilizing said light. Accordingly, the PH3 is separated from other raw gas and introduced into a reaction pipe 11, a light is made to irradiate on the PH3 flowing the PH3 introducing pipe 12 from a light source 18 before the PH3 is introduced to the reaction pipe 11, and the PH3 can be decomposed much quicker than before. As the temperature rise is not generated at the PH3 introducing pipe 12 when the above-mentioned photochemical reaction is performed, there is no possibility of having the intermediate reaction which is generated in the past.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an organometallic vapor phase epitaxy method for growing a phosphorus compound semiconductor using phosphine (PH3) gas.

(Prior Art) Phosphorus compounds have been attracting attention and research as semiconductor materials for optoelectronic and high-speed devices (Reference: Journal of Crysta
l Growth LJ, (1984), p 144~
14B). A typical conventional apparatus used for growing this phosphorus compound is schematically shown in FIG. In Figure 2, 11
is a reaction tube, 12 is phosphine (PH3) to this reaction tube
13 is a raw material gas introduction pipe for introducing raw material gases other than PH3 into the reaction tube 11; 14 is a high-frequency heating coil provided around the outer periphery of the reaction tube 11; 15 is a reaction tube A graphite susceptor 1B provided inside the tube 11 is a substrate placed on this susceptor 15.

Generally metal organic chemical vapor deposition method (hereinafter referred to as MOCVD)
When growing a phosphorus compound using
H3 is thermally decomposed, reacts, and grows. Since the thermal decomposition efficiency of phosphine (PH3), which is a raw material gas for phosphorus, is lower than that of arsine (ASH3), phosphine was not sufficiently decomposed on the substrate 16. In order to promote the decomposition of this phosphine on the substrate 18, conventionally a heating furnace for thermal decomposition of PH3 is provided around the PH3 introduction tube 12, as shown at 17 in FIG. 2, to introduce PH3 into the reaction tube 11. Previously this P
A technique was used in which H3 was thermally decomposed.

The temperature of this pyrolysis furnace is generally about 400 to 800°C.

(Problem to be solved by the invention) However, this f-horn: is because the temperature of the gas itself becomes -I-';t due to the thermal decomposition of pH3.
Intermediate reactions are likely to occur with other raw materials, especially alkyl compounds, in the reaction tube. As a result, the reaction between the original alkyl compound and the hydride does not take place on the substrate, leading to problems in that good growth is not achieved and the properties of the grown layer are not sufficiently good.

The purpose of this invention is to prevent the temperature of PH3 from exceeding 10 A caused by thermal decomposition before introducing the PH3 into the reaction tube, and to remove the intermediate reaction induced by the above-mentioned temperature. An object of the present invention is to provide an organometallic vapor phase epitaxy method in which the decomposition of PH3 is promoted without raising the temperature and the PH3 is introduced into a reaction tube.

(Means for Solving the Problems) In order to achieve this object, according to the present invention, phosphine gas is separated from other raw gases and decomposed individually using a photochemical reaction, and then reacted. It is characterized in that it is introduced into the tube 11 (Fig. 1).

(Function) Since phosphine gas PH3 absorbs light of 200 to 220 nm, this light can be used to
can be decomposed by a photochemical reaction without causing a rise in temperature. Therefore, PII3 is fractionated separately from other raw material gases and introduced into the reaction tube 11, and before being introduced into the reaction tube 11, PH3 flowing through the PH3 introduction tube I2 is irradiated with light from a light source, By carrying out a photochemical reaction, the decomposition of P113 can be promoted far more than in the past. This photochemical reaction takes place at this pH
3. Since there is no temperature rise at the introduction pipe 12, there is no risk of intermediate reactions occurring as in the conventional case.

(Example) Hereinafter, the organometallic vapor phase epitaxy method of the present invention will be explained with reference to FIG. Components in FIG. 1 that are the same as those shown in FIG. 2 are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 1 is a diagram illustrating the outline of an apparatus for carrying out the metalorganic vapor phase epitaxy method of the present invention.

In this invention, the light source 18 is used instead of the conventional pyrolysis furnace.
3 installed around the introduction pipe 12. This light source 18 has a pH of 3
It is appropriate to use a light source such as a deuterium lamp or a mercury-cannon lamp, which has an emission wavelength in the 200 to 22 Onm absorption wavelength range. The light from this light source 18 is installed so that it can irradiate only the PH3 introduction tube 12,
Avoid irradiating source gases such as other alkyl compounds.

In this way, the PH flowing through the PH3 introduction pipe 12
Before the PH3 is introduced into the reaction tube 11, the PH3 is irradiated with light to cause a photochemical reaction, thereby making it possible to decompose the PH3 without raising the temperature by 1.

After being decomposed in this way, it is introduced into the reaction tube 11, and together with other raw material gases, thermal decomposition and reaction occur on the heated substrates 1B and 11, and a growth layer is deposited. You can.

In this case, the flow rate of the PH3 gas, the time of light irradiation, and other conditions can be arbitrarily and appropriately set as required.

(Effects of the Invention) As is clear from the two consecutive explanations, according to the organometallic vapor phase growth method according to the present invention, since PH3 is decomposed by a photochemical reaction without heating, alkyl metals, etc. and reaches the substrate without any intermediate reactions. Since this decomposed PH3 gas reacts between all the raw materials on the substrate, it is possible to grow crystals with good properties, and in particular, it is possible to prevent contamination with impurities.

Furthermore, there is no thermal stress in the growth apparatus for carrying out the present invention, and the growth apparatus uses hazardous gas.
It is possible to simplify the design of the OCVD method equipment.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing an apparatus for carrying out the metal-organic vapor phase epitaxy method of the present invention, and FIG. 2 is a diagram of an apparatus for explaining a conventional method. It is. DESCRIPTION OF SYMBOLS 11... Reaction tube, 12... PH3 introduction tube 13... Raw material gas introduction tube, 14... High frequency heating coil 15... Graphite susceptor 16... Substrate, 18... Light source. Patent applicant Oki Electric Industry Co., Ltd. Procedural amendment April 18, 1986

Claims (1)

[Claims] In the organometallic vapor phase epitaxy method in which phosphorus compound semiconductors are grown using phosphine gas in a reaction tube, the phosphine gas is separated from other source gases and decomposed individually using a photochemical reaction before being introduced into the reaction tube. An organometallic vapor phase epitaxy method characterized by: