Indium in silicon: interactions with native defects and with C impurities

摘要

Equilibrium geometries and formation energies of neutral and charged In complexes with silicon native defects (vacancy (Ⅴ) and self-interstitials (Ⅰ)) and with C impurities are investigated within density functional theory, using the Vienna Ab-initio Simulation Package. We determine formation energies and ionization levels of different complexes and discuss the contribution of Ⅰ and Ⅴ to indium diffusion. We also identify the In-C defect responsible for the increased electrical activation in In+C-doped silicon samples. The ab initio energetics is then implemented in a continuum diffusion code in order to simulate the diffusion of as-implanted In profiles under different thermal treatments.