Fabrication of Heavily-Doped Polycrystalline Silicon Film Using a Laser-Doping Technique

Abstract

A structure composed of alternating layers of hydrogenated amorphous silicon (a-Si:H) film and either phosphorus or boron film was used to fabricate low-resistivity polycrystalline silicon (poly-Si) film at low temperature. This structure was formed by a radio-frequency glow discharge process at 230°C and then irradiated by a pulsed XeCl excimer laser at room temperature. Simultaneous crystallization and uniform diffusion of the dopant atoms was achieved. The 240 nm-thick boron-doped poly-Si film had a sheet resistivity of 23 Ω/\Box (ρ=5.5×10^-4 Ωcm).