Effects of HWCVD-deposited Seed Layers on Hydrogenated Microcrystalline Silicon Films on Glass Substrates

Abstract

Microcrystalline silicon was deposited by hot-wire chemical vapor deposition (HWCVD) using a graphite filament with and without a thin 50 nm microcrystalline silicon seed layer. Increasing silane concentration diluted in H2 led to a decrease in crystalline fraction as well in a decrease in dark conductivity and photo-conductivity. In addition, films deposited with a seed layer were found to have higher dark conductivity and photo-conductivity than those without a seed layer but deposited at slower growth rates. However, Raman spectroscopy showed that use of a seed layer resulted in only a small increase in crystalline fraction at the surface of the films which had thicknesses between 250-400nm. TEM measurements confirmed the crystalline nature of deposited films showing average grain sizes of 25 nm.

Structural Analysis of Nanocrystalline Silicon Prepared by Hot-wire Chemical Vapor Deposition on Polymer Substrates

“…Amorphous and nanocrystalline films were deposited in a commercially available HWCVD chamber [5]. Two straight 10 cm Ta filaments were heated up to a filament temperature of 1850°C measured using an optical thermometer.…”