| 摘要 |
A method of chemical vapour deposition characterised in that it comprises: (A) producing a first gas stream comprising a Group III organometallic gas and a carrier gas; (B) producing a second gas stream comprising an elemental Group V metal gas from an elemental source and a carrier gas; and (C) supplying said gas streams to a reactor where they react to form a III-V semiconductor; and, optionally (D) supplying hydrogen gas to said reactor is disclosed. A chemical vapour deposition apparatus characterised in that it comprises: (A) first means (8) for producing a first gas stream comprising a Group III organometallic gas and a carrier gas; (B) second means (6) for producing a second gas stream comprising an elemental Group V metal gas from an elemental source and a carrier gas; and (C) a reactor (4) to which said gas streams are supplied where they react to form a III-V semiconductor; and, optionally, D) third means for supplying hydrogen gas to said reactor is also disclosed. The present invention provides advantages over the prior art. The arsine, phosphine and trimethyl triethyl, or trialkyl arsine or trialkyl phosphine adducts of triethyl or trimethyl indium sources of the prior art are replaced by one or more pnictide (Group V) bubblers; that is, heated sources of elemental pnictides through which a carrier gas is allowed to flow. The elemental pnictide gas and the carrier gas are supplied in a stream as are a Group III organometallic gas, a carrier gas, and hydrogen to a chemical vapour deposition reactor where they react to form III-V semiconductors surface layers on a substrate. The carrier gas may be nitrogen, or a noble gas, such as argon. Alternatively, hydrogen may be used as the carrier gas so that the reaction is carried out in an exclusive hydrogen atmosphere. At least some of this hydrogen may be monoatomic hydrogen. The substrate may be a III-C semiconductor or glass. Products include layers of gallium arsenide, indium phosphide and alloys thereof, including gallium indium arsenide and gallium aluminium arsenide. Other ternary and quaternary III-V semiconductors are produced using appropriate combinations of sources of Group III organometallic gases and Group V elemental gases produced by bubblers. The products may be used in semiconductor devices including solar cells. |
