CHARACTERIZATION OF EXCIMER-LASER ANNEALED POLYCRYSTALLINE SI1-XGEX ALLOY THIN-FILMS BY X-RAY-DIFFRACTION AND SPECTROSCOPIC ELLIPSOMETRY

Thin films of Si1-xGex alloys of different compositions x have been de posited, on single-crystal Si (100) surface and glass substrates, by s imple ion beam sputtering, at room temperature. Crystallization of the se films has been done using excimer laser annealing. Structural and o ptical properties of as-deposited and annealed Si1-xGex alloy films ar e characterized by x-ray diffraction (XRD), uv-visible spectrophotomet ry, spectroscopic ellipsometry (SE), and Auger electron spectroscopy ( AES). The as-deposited films, both on Si and glass, have been found to be amorphous by XRD, Polycrystalline nature of laser-annealed samples has been evidenced by both x-ray and SE measurements. The results of x-ray, uv-visible, AES, and SE are compared and discussed. The poly-Si 1-xGex films were oriented predominantly to (111) and the grain sizes were determined from half-width of x-ray peaks. The compositions x of Si1-xGex films have been evaluated from the SE dielectric function eps ilon(omega) data, using the second-derivative technique, and are found to be 0.23 and 0.36 for two different compositions. A detailed analys is of epsilon(omega) with the effective-medium theory has demonstrated the volume fraction of crystalline Si1-xGex increases with the increa sing energy of laser irradiation. (C) 1998 American Institute of Physi cs.