Polysilicon Thin-Film Transistors Processed at Low Temperature ( \Leq600°C) Using Solid-Phase Crystallization in Wet Oxygen Atmosphere

The spin density and oxygen concentration of polysilicon films have been successfully reduced using a novel solid-phase-crystallization (SPC) method in an ambient of wet oxygen. The threshold voltage (V th), subthreshold swing (S) and field-effect mobility (µ FE) for thin-film transistors (TFTs) processed at ≦600° C using the polysilicon films were 2.0 V, 0.27 V/dec, and ∼35 cm2/ V·s, respectively. This performance was achieved with one-third less plasma hydrogeneration time than that of the conventional SPC method in an ambient of nitrogen.