PNNL

Abstract

Understanding dynamic processes during ion-implantation requires fundamental knowledge on defect properties, defect generation in atomic collision processes and multiple ion-solid interactions. The defect properties calculated using density functional theory (DFT) in SiC are consistent with multi-axial channeling measurements. Molecular dynamics (MD) methods have been employed to study defect generation and clustering due to ion interactions with SiC and structural evolution. The surviving defects are dominated by C interstitials and vacancies, and the number and size of clusters are very small, in agreement with those observed experimentally. The multiple ion-solid interaction, defect accumulation and disordering on Si and C sublattices are studied by simulating a large number of cascade overlap events. The damage accumulation, relative disordering and volume swelling obtained experimentally and from molecular dynamic simulations are in good agreement. Thus, the present studies provide atomic-level insights into the interpretation of experimentally observed features in SiC.