Structural characterisation of polycrystalline SiGe thin film

Amorphous Si1-xGex films, with a varying germanium. fraction, were deposite d using radio frequency (r.f.) sputtering and annealed under different cond itions to form polycrystalline films. The structural properties of the film s were examined using X-ray diffraction (XRD) and Raman spectroscopy. From the XRD and Raman spectra, the crystallinity of the films was observed to i mprove with an increase in annealing temperature and duration, and with inc reasing germanium fraction. An anomalous retardation in the crystallisation rate was attributed to the presence of impurities within the films. The im purities, together with an increased nucleating site density, caused a sign ificant reduction in the extracted grain size. (C) 2001 Elsevier Science Lt d. All rights reserved.