Hydrogenated amorphous-silicon thin films (a-Si:H) were deposited by microwave plasma chemical-vapour decomposition of SiH4, on thin polyethylene sheets. The high-resolution, far infrared measurements were performed on these films in the 700–50 cm−1 region on a Nicolet far infrared interferometer. The use of polyethylene as the substrate material permitted the determination of the absorption bands at 656.4, 652, 639.4, and 543 cm−1 with a shoulder at 539 cm−1 and a broad feature at 70.8 cm−1. These features provided evidence for SiH, SiH2 (as predicted by Lucovsky et al.), and SiH3 combinations in the film, as well as far more complex systems.
Expand bandwidth high reflectivity of the far infrared region
