Evolution of SiGe nanoclusters and micro defects in the Si1−xGex layer fabricated by two-step ion implantation and subsequent thermal annealing

The Si1−xGex thin layer is fabricated by two-step Ge ion implantation into (0 0 1) silicon. The embedded SiGe nanoclusters are produced in the Si1−xGex layer upon further annealing. The number and size of the nanoclusters changed due to the Ge diffusion during annealing. Micro defects around the nanoclusters are illustrated. It is revealed that the change of Si–Si phonon mode is causing by the nanoclusters and micro defects.