Analysis of ion beam induced damage and amorphization of 6H-SiC by Raman scattering

Raman scattering analysis of damaged SiC layers obtained by 200 keV Ge+ ion implantation into 6H-SiC has been performed as a function of the implanted dose (up to 10(15) cm(-2)) and annealing temperature (up to 1500 degrees C). The results obtained show the presence of three different damage levels: low damage level (doses less than or equal to 3 x 10(12) cm(-2)), medium to high damage level (doses between 10(13) and 10(14) cm(-2)), and formation of a continuous amorphous layer for doses higher than the amorphization threshold of 2-3 x 10(14) cm(-2). Moreover, at doses of about 10(14) cm(-2) (below the amorphization, threshold) amorphous domains are already observed. The Raman spectra indicate the existence of structural differences between the amorphous phase at doses below and above the threshold. After annealing, there is a residual damage which cannot be removed even at the highest annealing temperature of 1500 degrees C. Differences in residual damage between the samples implanted at doses of 10(14) and 10(15) cm(-2) and annealed at the highest temperatures are observed from the peaks in the 1000-1850 cm(-1) spectral region. Finally, annealing at the highest temperature is required to observe the complete disappearance of the amorphous bands.