Supersaturated rare earth doped semiconductor layers formed by chemical vapor deposition
AssigneeInternational Business Machines Corporation
InventorDavid B. Beach
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Abstract
A CVD process for producing a rare earth-doped, epitaxial semiconductor layer on a substrate is disclosed. 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.
Claims25
A rare earth-doped semiconductor layer comprising a semiconductor consisting of silicon, germanium, or silicon-germanium and a rare earth element in substantially a single phase at a concentration which is higher than the equilibrium concentration for a single phase of said rare earth in said semiconductor layer and wherein said layer is substantially free of rare earth silicide and rare earth germanide precipitates.
An optically active epitaxial film comprising a semiconductor consisting of silicon, germanium, or silicon-germanium and from about 8.times.10.sup.18 to about 8.times.10.sup.19 atoms/cm.sup.3 of a rare earth element, said film being substantially free of rare earth silicide and rare earth germanide precipitates.
A rare earth doped semiconductor layer, comprising:
- a layer of a silicon, germanium or mixture thereof and a high concentration of a rare earth element said high concentration being higher than the equilibrium concentration for a single phase of said rare earth element in said semiconductor layer, said layer being substantially free of rare earth semiconductor precipitates;
- said layer being formed by a chemical vapor deposition process for creating a layer on a substrate comprising depositing said layer by thermal decomposition of a gaseous precursor mixture of a silane, germane or mixture thereof and a rare earth compound.
Dependencies are inferred from the claim text.