Background doping dependence of silicon diffusion on p-type GaAs

Junction depth measurements via scanning electron microscopy and secondary ion mass spectroscopy are used to characterize silicon diffusion in GaAs crystals that contain varying amounts of zinc background doping. The zinc concentration is found to control the silicon diffusion process. A reason for this is suggested based on the shift in Fermi level with increased p-type doping. Also, the electric field due to the p-n junction formed at the silicon diffusion front is shown to have a large effect on the zinc background doping profile.