Deposition of silicon germanium on silicon-on-insulator structures and bulk substrates
AssigneeASM America, Inc.
InventorMatthias Bauer
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Abstract
Methods are provided for producing SiGe-on-insulator structures and for forming strain-relaxed SiGe layers on silicon while minimizing defects. Amorphous SiGe layers are deposited by CVD from trisilane and GeH4. The amorphous SiGe layers are recrystallized over silicon by melt or solid phase epitaxy (SPE) processes. The melt processes preferably also cause diffusion of germanium to dilute the overall germanium content and essentially consume the silicon overlying the insulator. The SPE process can be conducted with or without diffusion of germanium into the underlying silicon, and so is applicable to SOI as well as conventional semiconductor substrates.
Claims22
A method comprising:
- depositing an amorphous SiGe layer on a silicon-on-insulator (“SOI”) substrate by chemical vapor deposition (“CVD”), the amorphous SiGe layer having a first germanium concentration;
- depositing a SiO2 layer over the amorphous SiGe layer;
- and
- after depositing the SiO2 layer, melting the amorphous SiGe layer at a temperature greater than 1000° C., thereby creating a SiGe-on-insulator substrate having a SiGe portion with a second germanium concentration that is less than the first germanium concentration.
Dependencies are inferred from the claim text.