Characterization of Ga out-diffusion from GaAs into SiOxNy films during thermal annealing

Abstract

The out-diffusion of Ga atoms during thermal annealing from a GaAs substrate into an SiOxNy encapsulating film has been studied using secondary ion mass spectrometry. The concentration of Ga atoms detected within the SiOxNy encapsulant annealed at 850 °C is found to increase with increasing the oxygen content of the encapsulant. The results are well correlated with the concentration change of the electron trap EL5 (Ec−ET =0.42 eV) evaluated from deep-level transient spectroscopy. We conclude that the controlled Ga out-diffusion by SiOxNy capped annealing causes enhanced electrical activation of Si implants and the generation of the EL5 trap during thermal annealing is ascribed to the Ga out-diffusion.