PNNL

Abstract

Single-crystal (001) ß-SiC (3C) films have been irradiated with 360 keV Ar2+ ions at 175, 310 and 375 K and the damage accumulation after each incremental fluence has been measured in situ by Rutherford backscattering spectroscopy in channeling geometry (RBS/C) along the [011] direction using the dual beam facilities within the Ion Beam Materials Laboratory at Los Alamos National Laboratory. The relative rate of disordering along [011] decreases with increasing temperature. The critical dose for the relative disorder to reach the random level along [011] is 0.35 dpa (17.5 eV/atom), 0.44 dpa (22.0 eV/atom) and 0.61 dpa (30.5 eV/atom) at 175, 310 and 375 K, respectively. The sigmoidal increase in relative disorder with dose is consistent with defect accumulation processes. Although RBS/C along [011] indicates a fully random layer at the highest dose for each temperature, ex situ RBS/C and XTEM along [001] indicate some residual crystallinity remains near the surface and the end of range.