Damage accumulation and annealing in 6H-SiC irradiated with Si+

Damage accumulation and annealing in 6H-silicon carbide (alpha-SiC) single crystals have been studied in situ using 2.0 MeV He+ RES in a [0 0 0 1]-axial channeling geometry (RBS/C). The damage was induced by 550 keV Si+ ion implantation (30 degrees off normal) at a temperature of -110 degrees C, and the damage recovery was investigated by subsequent isochronal annealing (20 min) over the temperature range from -110 degrees C to 900 degrees C. At ion fluences below 7.5 x 10(13) Si+/cm(2) (0.04 dpa in the damage peak), only point defects appear to be created. Furthermore, the defects on the Si sublattice can be completely recovered by thermal annealing at room temperature (RT), and recovery of defects on the C sublattice is suggested. At higher fluences, amorphization occurs; however, partial damage recovery at RT is still observed, even at a fluence of 6.6 x 10(14) Si+/cm(2) (0.35 dpa in the damage peak) where a buried amorphous layer is produced. At an ion fluence of 6.0 x 10(15) Si+/cm(2) (-90 degrees C), an amorphous layer is created from the surface to a depth of 0.6 mu m. Because of recovery processes at the buried crystalline-amorphous interface, the apparent thickness of this amorphous layer decreases slightly (<10%) with increasing temperature over the range from -90 degrees C to 600 degrees C. (C) 1998 Elsevier Science B.V. All rights reserved.