PNNL

Abstract

Damage evolution and isochronal recovery have been studied in single crystal 4H and 6H SiC irradiated with 1.1 MeV Al2 molecular ions at 150 K to ion fluences ranging from 0.15 to 2.85 Al+/nm2. The damage evolution and recovery on both the Si and C sublattices were determined using a 0.94 MeV deuterium beam in ion channeling geometry by simultaneously measuring the scattering/reaction yield from Rutherford backscattering spectrometry combined with 12C(d,p)13C nuclear reaction analysis. The rate of damage evolution at 150 K is higher for 4H-SiC than for 6H-SiC. At low doses, the rate of C disordering is higher than that for Si, which is consistent with the lower displacement energy for C. Both 4H and 6H SiC exhibit only minor damage recovery below 300 K. Above 300 K, damage recovery on the Si and C sublattices is similar for both 4H and 6H SiC. Three distinct recovery stages are observed on each sublattice in 4H-SiC, and at high doses, where a buried amorphous layer is produced, an additional recovery stage is observed above 800 K.