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.

► The embedded SiGe nanoclusters in Si1-xGex layer were fabricated by two-step Ge ion implantation and subsequent annealing in this work. ► Two kinds of anneal processes (FA & RTA) were used. ► We found that the micro-defects can be avoided by RTA process, which anneal time should less than 480 s. ► The structural properties during annealing were discussed in detail. ► Additionally, the phonon confinement effect has been found by the Si-Si phonon modes investigation obtained from the Si matrix and SiGe layer, respectively.