Low-temperature Al-induced crystallization of hydrogenated amorphous Si1−xGex (0.2 ≤ x ≤ 1) thin films

Low-temperature Al-induced crystallization of hydrogenated amorphous silicon–germanium thin films has been investigated by X-ray diffraction, Raman spectra and scanning electron microscopy measurements. It was shown that the Al-induced layer exchange significantly promotes the crystallization of the films. The influence of the annealing temperature and the Ge fraction on X-ray diffraction patterns and Raman spectra was analyzed. The increase in Raman peak intensity was observed with the increase of the annealing temperature, and the high-frequency shifts of Ge–Ge and Si–Ge peaks were found with the increase of the Ge fraction. There is an enhancement in film crystallinity and grain size with the increase of the Ge fraction and annealing temperature.