Microstructure characterization of SiCl4-based microcrystalline silicon films by effusion of implanted helium

Microcrystalline Si:Cl:H films prepared by plasma deposition using mixtures of silicon tetrachloride and hydrogen as process gases were studied by effusion of implanted helium. The temperature of maximum (low temperature) effusion rate is used as a measure of material density and microstructure. The results suggest that chlorine incorporation at concentrations exceeding a few percent results in a void-rich structure. High p-type conductivities obtained for boron-doped microcrystalline Si:Cl:H are explained by the presence of rather dense material with high crystalline fraction.