PNNL

Abstract

Epitaxial 4H-SiC has been irradiated at 150 K with 1.1 MeV Al2 molecular ions to fluences ranging from 1.35 x 1013 to 8.00 x 1014 Al? cm-2. The damage accumulation on both the C and Si sublattices of the as-implanted samples indicates a sigmoidal dependence on ion fluence, and a buried amorphous layer is formed at 2.00 x 1014 Al? cm-2. The width of the damage peak is unchanged until the local dose at the damage peak exceeds a critical amorphization value (0.12 dpa). The evolution and isochronal recovery of the buried amorphous layers at higher fluences were investigated by in-situ Rutherford backscattering spectrometry rapidly at 2.00 x 1014 Al? cm-2 and eventually saturated at a thickness of about 500 nm at high fluences. Recovery processes occurred at both the rear interface and in the surface region, and relative amount of recovery decreased with increasing fluence for temperatures up to 870 K. No recovery is observed at or near the surface at the highest fluence, which supports the absence of any residual crystallinity in the surface region.