PNNL

Abstract

Atomic-level simulations have been employed to study the defects and nanoscale disordering induced in 3C-SiC by C, Si, and Au ions with energies up to 50 keV. Energetic C and Si ions primarily produce interstitials, vacancies, antisite defects, and small defect clusters directly during the collision cascade. The overlap of Si cascades produces nanoscale defect clusters. In the case of energetic Au ions, nanoscale amorphous domains are produced directly within the Au cascade along with point defects and smaller clusters. In about 25% of the 50 keV Au cascades, one or more of the subcascades contain nanoscale clusters that exhibit a structure that is consistent with an amorphous state. Structural image simulations of the subcascade structures produced by energetic Si and Au recoils are consistent with experimental high-resolution transmission electron microscopy images. Simulations on close-pair production and recombination in SiC indicate that the activation energies for recombination of most close pairs range from 0.24 to 0.38 eV.