Radiation Response and Defect Dynamics in Strained Si

Texas A&M Engineering Experiment Station, College Station TX

Investigators

Abstract

Technical: This project investigates the role of strain in damage cascade formation and subsequent defect clustering in ion irradiated and annealed Si. The approach places emphasis on the growth of Si under different strain using molecular beam epitaxy. Cluster ion bombardment will be used to study amorphization mechanisms of the strained Si. In a parallel study using monomer ion irradiation, boron doped Si superlattice structures will be used to detect the flux of Si interstitials during post-irradiation thermal annealing. The measured transient interstitial supersaturation will be used as input to an inverse modeling of Ostwald ripening to obtain formation energies of defect clusters as a function of cluster size. Combining the experimental approaches with molecular dynamics simulations, the project aims for a comprehensive picture of defect development in strained silicon. Non-technical: This project addresses basic research issues in a topical area of materials science with high technological relevance. The capability to predict processing parameters in strained silicon is critical to promoting strain technology, optimizing the doping and annealing process in device fabrication, and evaluating device reliability in harsh environments involving particle irradiation. The project integrates research and education, and conducts outreach through the following activites: (1) increase minority participation in emerging materials research; (2) develop curricula; (3) create e-learning resources to integrate research, teaching and curriculum development for promoting public learning in frontiers of materials science; and (4) develop the Center of Ion & Materials Research at Texas A&M University and use it as a platform for interdisciplinary research and teaching.