| 摘要 |
This invention provides a process for growing Ge epitaxial layers on Si substrate by using ultra-high vacuum chemical vapor deposition (UHVCVD), and subsequently growing a GaAs layer on Ge film of the surface of said Ge epitaxial layers by using metal organic chemical vapor deposition (MOCVD). The process comprises steps of, firstly, pre-cleaning a silicon wafer in a standard cleaning procedure, dipping it with HF solution and prebaking to remove its native oxide layer. Then, growing a high Ge-composition epitaxial layer, such as Si<SUB>0.1</SUB>Ge<SUB>0.9 </SUB>in a thickness of 0.8 mum on said Si substrate by using ultra-high vacuum chemical vapor deposition under certain conditions. Thus, many dislocations are generated and located near the interface and in the low of part of S<SUB>i01.</SUB>Ge<SUB>0.9 </SUB>due to the large mismatch between this layer and Si substrate. Furthermore, a subsequent 0.8 mum Si<SUB>0.05</SUB>Ge<SUB>0.95 </SUB>layer, and/or optionally a further 0.8 mum Si<SUB>0.02</SUB>Ge<SUB>0.98 </SUB>layer, are grown. They form strained interfaces of said layers can bend and terminate the propagated upward dislocation very effectively. Therefore, a film of pure Ge is grown on the surface of said epitaxial layers. Finally, a GaAs epitaxial layer is grown on said Ge film by using MOCVD.
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