Samples of GaAs, which were encapsulated with thin films of amorphous Si at 450C, were annealed at temperatures of up to 1050C. The resultant poly-Si/GaAs interfaces were investigated by using secondary ion mass spectroscopy, Rutherford back-scattering spectrometry, and transmission electron microscopy. Little or no interdiffusion was detected at undoped Si/GaAs interfaces. The diffusion of dopants such as InP was detected. An enhanced diffusivity of In into GaAs was attributed to the diffusion of point defects which were created by the diffusion of As and Ga into the encapsulant. It was deduced that the In diffusivities in GaAs at doped polycrystalline Si interfaces were enhanced by factors of about 10000.

The Interdiffusion of Si, P, and In at Polysilicon/GaAs Interfaces. K.L.Kavanagh, C.W.Magee, J.Sheets, J.W.Meyer: Journal of Applied Physics, 1988, 64[4], 1845-54