Raman, transmission electron microscopy, and conductivity measurements in molecular beam deposited microcrystalline Si and Ge: A comparative study
Abstract
The structure of molecular beam deposited microcrystalline silicon and germanium films prepared under different growth conditions has been analyzed by conventional transmission electron microscope (TEM) and Raman scattering (RS) and compared to electrical conductivity experiments. The TEM measurements yield an average grain size L0 ranging from 200 Å to 1.5 μm. On the other hand, the line shape of the RS is determined by a mean free path related to the average separation l between defects (or impurities), where l≤150 Å. We find in a number of cases that the electrical conductivity is determined by l rather than L0. This experiment demonstrates the significance of RS as a structural characterization method when used in conjunction with other techniques such as TEM.