Structure and hydrogen content of stable hot-wire-deposited amorphous silicon

Abstract
Thin-film transistors incorporating a hot-wire chemical-vapor-deposited silicon layer have been shown to exhibit superior electronic stability as compared to glow-discharge-deposited amorphous silicon devices. Hot-wire-deposited silicon films of various thicknesses (37–370 nm) on silicon dioxide were investigated. The films are structurally inhomogeneous. Raman measurements and transmission electron microscopy show that isolated cone-shaped crystals grow within a primarily amorphous layer. The amorphous interface region has a low hydrogen content of 2.0±0.2 at. %, while the films exhibit an enhanced hydrogen concentration in the surface region. The bond-angle distribution in the amorphous phase is comparable to that of device-quality glow-discharge-deposited amorphous silicon.