Damage behaviour and annealing of germanium implanted 6H-SiC

The present paper reports a study of the defect reduction and recrystallisation during annealing of Ge⁺-implanted 6H-SiC. Implants have been performed at 200 keV with doses of 1×10¹⁴ and 1×10¹⁵ cm^-2. Furnace annealing has been carried out at temperatures of 500, 950 and 1500°C. Several analytical techniques including Rutherford backscattering spectrometry in conjunction with channelling (RBS/C), cross-sectional transmission electron microscopy (XTEM), positron annihilation spectroscopy (PAS), Raman Scattering (RS), and Electron Paramagnetic Resonance (EPR) measurements have been employed for sample characterisation. It has been shown that damage removal is more complicated than in ion-implanted Si. Using PAS deeply diffusing vacancy-like defects were found far below the region defined by TRIM as containing the maximum amount of nuclear energy deposition. The amorphised SiC is characterised by carbon dangling bonds as revealed by EPR. The recrystallisation of amorphised SiC layers has been found to be unsatisfactory for temperatures up to 1500°C. The use of ion-beam-induced epitaxial crystallisation (IBIEC) has been more successful as lattice regrowth, although still imperfect, has been observed to occur at a temperature as low as 500°C