Recrystallization of amorphous ion-implanted silicon carbide after thermal annealing

摘要

Single crystals of 6H-SiC were implanted at room temperature with 4-MeV Au ions to a fluence of 10~(15)cm~(-2). Raman spectra showed that full amorphization was achieved. The recrystallization process was studied by micro-Raman spectrometry after isochronal thermal annealing between 700 and 1500°C. The spectra permitted the evolution upon annealing of Si-C bonds, and also of Si-Si and C-C bonds, to be followed. Amorphous phase relaxation takes place below 700°C; then recrystallization of the 6H polytype sets in at 700°C. At 900°C crystallites with different crystalline states are formed. Moreover, Raman spectra provide evidence of graphitic nanocluster formation at 1500°C.