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.