The Diffusion of Phosphorus and Indium into Gallium Arsenide from Polycrystalline-Silicon

Arsenic or phosphorus doped polycrystalline-Si (poly-Si) acts as a diffusion source when deposited on GaAs. Non-Fickian Si diffusion into GaAs has been observed following heat treatments above 700°C. In this paper, the diffusion of In and P from poly-Si at temperatures between 800 and 1020°C is presented. These impurities, introduced into the poly-Si by in-situ plasma deposition, implantation or vapor annealing, diffuse rapidly into the GaAs. Results from particle induced x-ray analysis, transmission electron microscopy, Rutherford backseat tering and secondary ion mass spectroscopy indicate 80% substitutional In and P at interface concentrations of approximately 10 and 25 at%, respectively.