Photo-Conductive, Low Impurity-Diffusive, Heat-Resisting a-Si Formed by Glow-Discharged Decomposition of SiF2 and H2 Mixture

Abstract

A new type of hydro-fluorinated amorphous-silicon (a-Si: F: H) is formed by the glow-discharged decomposition of H₂ and SiF₂ gas mixture. SiF₂ is intermediate-state active gas and produced by chemical reaction between SiF₄ gas and solid silicon. Deposition rate and photo-conductive property of this a-Si: F: H are studied for various deposition conditions. Change of its property due to annealing and impurity diffusion in it are also studied. It is found that this a-Si: F: H is photo-conductive as highly as the best hydrogenated amorphous-silicon (a-Si: H) even for samples formed with high deposition rate near to 10 Å/sec, and also that the impurity diffusion in it is much smaller than that in a-Si: H, by at least by several orders of magnitude.