STM AND RAMAN-STUDY OF THE EVOLUTION OF THE SURFACE-MORPHOLOGY IN MU-C-SI-H

The structure of mu c-Si:H films deposited on graphite substrates has been investigated, using scanning tunneling microscopy and Raman scatt ering spectroscopy as a function of film thickness ranging from 1 to 1 0 nm. At the very initial stage of deposition, chemically active sites are created on the surface of the graphite substrate, which is eviden ced by a change in the graphite Raman bands. A change of the STM image found in the early stage of growth is interpreted in terms of a coale scence of nanostructures. The vertical surface roughness of mu c-Si:H is found to be much larger than that of a-Si:H, which can be explained by its inhomogeneous nature as well as crystallographic anisotropy of the mu c-Si:H film.