DEFECTS IN ELECTRON-IRRADIATED 3C-SIC EPILAYERS OBSERVED BY POSITRON-ANNIHILATION

Positron annihilation has been used to study defects induced by 1 MeV electron irradiation in cubic silicon carbide (3C-SiC) epitaxially gro wn on Si substrates by chemical vapor deposition. Narrowing of the Dop pler-broadened energy spectrum of annihilation gamma-rays by the elect ron irradiation was observed in the fluence range above 5 x 10(16) e/c m(2). The electron fluence dependence of the narrowing is accounted fo r by the introduction of monovacancies and divacancies in 3C-SiC by th e irradiation.