In situ and ex situ investigation of ion-beam-induced amorphization in alpha-SiC

Single crystals of alpha-SiC with [0001] orientation have been irradiated at 300 K with 360 keV Ar2+ ions at an incident angle of 25 degrees. The damage accumulation in one sample was followed in situ by Rutherford backscattering spectroscopy in channeling geometry (RBS/C) along the [<1(1)over bar 02>] direction until the aligned backscattering yield reached the random level throughout the irradiated layer at a fluence of 8 Ar2+ ions/nm(2). Six other samples were irradiated at fluences ranging from 1 to 6 Ar2+ ions/nm(2), and the damage accumulation was characterized ex situ by RBS/C along the [0001] direction. The relative disorder, as measured by RBS/C, increased with ion fluence; however, the observed rate of disordering was much lower when measured ex situ along the [0001] direction.