Some Physical Properties of Undoped Amorphous Silicon Prepared by a New Chemical Vapor Deposition Process Using Iodosilanes

A new method of preparation of a-Si by thermal decomposition (hetero- and homo-CVD) of di- and triiodosilanes is described. The iodosilanes were prepared by the reaction of phenylsilanes with HI. Uniform films on glass and indium/tin oxide coated glass were prepared with thicknesses ranging upto 4.0 μm. Rutherford backscattering spectrometry (RBS) reveals only a slight amount of oxygen, which appears to be on the surface of the film. In addition RBS indicates the presence of a slight amount of iodine that has a density that decreases gradually as a function of depth. FTIR analysis also indicates a slight amount of oxygen and very little hydrogen.