METHOD AND APPARATUS FOR THERMALLY DECOMPOSING A HALOGENATED HYDROCARBON TO PROVIDE A GASEOUS CARRIER MEDIUM FOR VAPOR EPITAXIAL GROWTH

摘要

A halogenated hydrocarbon such as chloroform is used as a source for a hydrogen halide, such as hydrogen chloride, which in turn is used as a transporting agent for vapor deposition. The hydrogen halide is obtained by thermal decomposition of the halogenated hydrocarbon. This is accomplished by saturating a carrier gas withe the halogenated hydrocarbon and then introducing the mixture into a cracking region of elevated temperature. Subsequent to introducing the newly formed transporting agent and its carrier gas into the growth apparatus, the mixture is passed through a cold trap which condenses all substances less volatile than the hydrogen halide. In the case of chloroform, for example, the HCl produced from thermal decomposition is passed over a III-V source material, such as GaAs, held at an elevated temperature to form a gaseous column III halide plus a column V vapor specie. These vapor species are carried to a lower temperature region where surface catalyzed deposition takes place on a substrate.