Thermal Diffusion of Buried Beryllium and Silicon Layer in GaAs Doped by Focused Ion Beam Implantation

Abstract
The diffusion profiles of buried Be and Si doped by focused ion beam (FIB) implantation in GaAs after annealing were investigated. The diffusion coefficients of Be and Si were determined by fitting from the results of computer calculations. The diffusion coefficient of FIB-doped Be was enhanced by excess interstitial Be. Beryllium diffusion profiles expand by annealing with a high dose at 850°C. The concentration-dependent diffusion of Si in GaAs doped using a molecular beam was observed. The diffusion coefficient of Si heavily doped by FIB, however, was undetectably small in contrast with that of Be at 850°C.