Surface‐roughness and grain‐boundary effects on the optical properties of low‐pressure chemical‐vapor‐deposited silicon thin films by spectroscopic ellipsometry

摘要: The optical properties of polycrystalline silicon thin films prepared by low‐pressure chemical vapor deposition were studied spectroscopic ellipsometry. surface roughness and the microstructure investigated combining theory Ohlidal Lukes with Bruggeman effective‐medium approximation. Furthermore, a line‐shape analysis dielectric function, as well method to describe was used discuss effect that crystallite size grain boundaries in these materials. results this show parameters mainly control growth mode materials, at temperature 630 °C, are silane pressure rate. different morphologies native oxide on material seem be associated film. measured data must taken into account even energies low 2 eV, while presence overlayer influences higher energies. A reasonable agreement recent electron microscopy studies materials found.