Diffusion studies of Be-implanted GaAs by SIMS and electrical profiling

Abstract

Secondary ion mass spectrometry (SIMS) has been used with differential resistivity and Hall effect measurements to study the 900°C diffusion of implanted Be in GaAs. Some outdiffusion of Be into the Si3N4 encapsulant occurs for surface Be concentrations above 1 × 1018cm−3. However, excellent agreement between the electrical and atomic profiles indicates that 85–100% of the Be remaining after annealing is electrically active. The concentration-dependent diffusion observed for implanted Be in GaAs was not significantly altered in experiments using hot substrate implants, two-step anneals, or annealing with Ga and As overpressure.