Redistribution of Cr in Capless-Annealed GaAs under Arsenic Pressure

Abstract

Redistribution of chromium (Cr) in Cr-doped semi-insulating GaAs annealed under widely changed conditions was studied by secondary ion mass spectrometry. Remarkable out-diffusion of Cr was observed from the surface of GaAs annealed above 800°C. This out-diffusion was found to be controlled by introducing arsenic partial pressure to the annealing ambient. Redistributed Cr profiles obtained experimentally were compared with the calculated ones, and a diffusion constant of Cr in GaAs was determined to be D=6.3×105 exp (-3.4 eV/kT).