Synthesis of oriented and passivated polycrystalline silicon films on glass by hot wire chemical vapor deposition

We report synthesis of highly (220) oriented and passivated polycrystalline silicon films on glass by using Hot Wire Chemical Vapor Deposition (HWCVD) without using any buffer. Oriented growth is initiated by deposition at 400°C using dilute mixture of Silane(SiH₄) and Hydrogen(H₂), a condition which favours growth of (220) oriented nuclei. After that most of the growth is done at 600-700°C using less dilute SiH₄ + H₂. Films are passivated by in-situ soak in atomic hydrogen between 400-300°C. At 300 K, films have dark conductivity about 10^-6 (Ω-cm)^-1. Illumination with a white light LED of flux about 1 sun increases the conductivity to 1-2x 10^-5 (Ω-cm)^-1. In addition photoluminescence emission is observed both at 18 K and at 300 K. These features suggest films are well passivated.