ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The growth of a Si/Si1−xGex/Si heterostructure at high Ge fractions was investigated by an ultraclean low-pressure chemical vapor deposition using SiH4 and GeH4 gases in the temperature range of 450–650 °C. It was found that a lowering of the deposition temperatures of the Si1−xGex and Si capping layers is necessary with the increasing Ge fraction in order to prevent island growth of the layer during deposition. For a Ge fraction around 0.2, atomically flat surfaces and interfaces can be obtained by depositing Si1−xGex and Si capping layers at 550 °C. For higher Ge fractions, even much lower deposition temperatures are suitable, namely 450 °C for a Si0.3Ge0.7 layer and 500 °C for a Si0.5Ge0.5 layer, respectively, with a Si capping layer deposited at temperatures of 550 °C or less. Nevertheless, the degradation of the Si0.3Ge0.7 layer with the capping layer was not observed even after a wet oxidation at 700 °C.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.108105
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