Evidence for a vacancy and interstitial mediated diffusion of As in Si and Si0.9Ge0.1

Abstract

Arsenic diffusion has been studied at 1000°C in Si and relaxed Si0.9Ge0.1 structures grown using molecular beam epitaxy. Intrinsic diffusivity of As in Si0.9Ge0.1 is shown to be enhanced over Si by a factor of 2, in agreement with the literature. Using selective point defect injection, obtained by surface reactions achieved using rapid thermal annealing process under oxygen atmosphere, clear evidence of the participation of both vacancy and interstitial defects in the diffusion process of As in Si as well as Si0.9Ge0.1 is obtained. Qualitatively, a higher contribution of vacancies in Si0.9Ge0.1 than in Si is apparent.