PECVD of Nanocrystalline Si Layers on High‐ T g Polymer Substrates

Summary: Hydrogenated nanocrystalline silicon (nc‐Si:H) was deposited by plasma‐enhanced chemical vapor deposition (PECVD) on transparent polymers in order to qualify these for possible use as electronic substrates. As a first step, plasma etch experiments in pure H 2 revealed small etch rates for these materials. Thin films of nc‐Si:H were then deposited on samples placed on the grounded electrode of a “Reinberg”‐type parallel plate RF (13.56 MHz) PECVD reactor, at various substrate temperatures (25 °C ≤ Ts ≤ 250 °C), using SiH 4 diluted in H 2 as the feed‐gas. Thermally induced failure of the nc‐Si:H/polymer composite was avoided within a certain range of deposition conditions, permitting structural and electrical characterization of the deposits.Temperature‐dependent conductivity, σ ( T ), for nanocrystalline silicon (nc‐Si:H) films on glass and three polymer substrates, all deposited at T s  = 175 °C.