Point defect-dislocation loop behavior in Si with a TiSi 2 film

Abstract

The behavior of end-of-range dislocation loops have been used to study the flux of point defects in Si after the formation of a TiSi 2 film. Extrinsic dislocation loops were formed in Si which then had 30 nm of Ti deposited and annealed to form TiSi 2. Control samples with loops but without a TiSi 2 film were annealed concurrently without a TiSi 2 film to provide a comparison. The density of the interstitials bound by the loops was measured by plan view TEM. Enhanced loss of interstitials bound by the loops in the silicided samples indicate a vacancy supersaturation caused by the presence of the TiSi 2 film. By assuming a constant flux of vacancies from the TiSi 2 Si interface to the layer of dislocation loops, we measure C V D V values, where C V = concentration of vacancies and D V = diffusivity of a vacancy. By using a literature estimate of C V ∗D V , where C V ∗ = equilibrium population of vacancies, we derive C V C V ∗ ∼ 1.2 for Si annealed with a TiSi 2 film, which is in substantial agreement with the value from a previous study.