| 摘要 |
A CVD process for producing a rare earth-doped, epitaxial semiconductor layer on a substrate is disclosed. The equipment is a 7.6 cm diameter ultra high vacuum chemical vapor deposition (UHVCVD) reactor wherein pumping and wafer loading are done using the same end of the reactor. This modification allows the installation of a heated precursor reservoir (1) on the opposite end of the reactor. The reservoir is connected to the reactor end flange using a short diameter stainless steel tubing (12). The reactor is heated by external resistive heating (4). The reactor is pumped both before and during deposition by a 150 L/sec turbomolecular pump (8) backed by a two-stage oil pump (9). The load lock chamber is also pumped by a turbomolecular pump (10) to prevent contamination from pump oil.The process utilizes a silane or germane and a rare earth compound in the gas phase. By this method single phase, rare earth-doped semiconductor layers, supersaturated in the rare earth, are produced. The preferred rare earth is erbium and the preferred precursors for depositing erbium by CVD are erbium hexafluoroacetylacetonate, acetylacetonate, tetramethylheptanedionate and flurooctanedionate. The process may be used to produce optoelectronic devices comprising a silicon substrate and an erbium-doped epitaxial silicon film. <IMAGE> |
