Impact of GaAs buffer thickness on electronic quality of GaAs grown on graded Ge/GeSi/Si substrates
- Department of Electrical Engineering, The Ohio State University, Columbus, Ohio 43210-1272 (United States)
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
- Amberwave Systems Corp., Woburn, Massachusetts 01801 (United States)
- National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)
Minority carrier lifetimes and interface recombination velocities for GaAs grown on a Si wafer using compositionally graded GeSi buffers have been investigated as a function of GaAs buffer thickness using monolayer-scale control of the GaAs/Ge interface nucleation during molecular beam epitaxy. The GaAs layers are free of antiphase domain disorder, with threading dislocation densities measured by etch pit density of 5x10{sup 5}-2x10{sup 6} cm{sup -2}. Analysis indicates no degradation in either minority carrier lifetime or interface recombination velocity down to a GaAs buffer thickness of 0.1 {mu}m. In fact, record high minority carrier lifetimes exceeding 10 ns have been obtained for GaAs on Si with a 0.1 {mu}m GaAs buffer. Secondary ion mass spectroscopy reveals that cross diffusion of Ga, As, and Ge at the GaAs/Ge interface formed on the graded GeSi buffers are below detection limits in the interface region, indicating that polarity control of the GaAs/Ge interface formed on GeSi/Si substrates can be achieved. (c) 2000 American Institute of Physics.
- OSTI ID:
- 20215789
- Journal Information:
- Applied Physics Letters, Vol. 76, Issue 14; Other Information: PBD: 3 Apr 2000; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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