MODELING THE DIFFUSION OF IMPLANTED BE IN GAAS

The diffusion of implanted Be in liquid-encapsulated Czochralski GaAs samples is modeled using SUPREM-IV.GS, a simulator for GaAs and Si pro cessing technology. The ''plus one'' approach for defect generation af ter implantation, as well as an assumption of local Ga interstitial si nks, are used to successfully simulate the high Be diffusivity, the up hill diffusion and the time-dependent Be diffusivity. The fast diffusi on of implanted Be can be simulated using the same intrinsic Be diffus ivity as that used in the simulation of the slow diffusion of molecula r beam epitaxy grown-in Be. The roles of extended defects and nonequil ibrium Ga point defects in the implanted Be anomalous diffusion behavi or are taken into account. (C) 1995 American Institute of Physics.