Auto-correlation function analysis of crystallization in amorphous SiGe thin films

The existence of medium-range ordering structures or nanocrystallites in as-deposited amorphous SiGe thin films has been demonstrated by high-resolution transmission electron microscopy in conjunction with auto-correlation function analysis. The density of nanocrystallites decreases in amorphous SiGe samples annealed at 300–350 °C then increases in samples annealed at 400–450 °C with annealing temperature. The observations can be interpreted in terms of free energy change with annealing temperature.