In situ X-ray diffraction study on epitaxial growth of SixGe1−xon Si by aluminium-assisted crystallization

In situ X-ray diffraction study is applied to investigate the role of annealing time in the epitaxial growth of SixGe1−xon Si by aluminium-assisted crystallization at relatively low temperatures (350–450 °C). The evolution of the SixGe1−xfilm with annealing time can be divided into two stages: (i) SixGe1−xepitaxial growth on Si through Ge/Al layer exchange and (ii) SixGe1-xdiffusion into Si substrate. The speed of layer exchange increases with elevating temperature. After the completion of layer exchange, the SixGe1−xstarts diffusing into the Si substrate with prolonged annealing time. The Si content of the epitaxial SixGe1−xfilm keeps increasing with time throughout the annealing. This increase is rapid during Ge/Al layer exchange but is gradual during SixGe1−xdiffusion into Si substrate.