High-performance and low-temperature-compatible p-channel polycrystalline-silicon TFTs using hafnium-silicate gate dielectric

Abstract

In this letter, high-performance p-channel polycrystalline-silicon thin-film transistors (TFTs) using hafnium-silicate (HfSiOx) gate dielectric are demonstrated with low-temperature processing. Because of the higher gate-capacitance density, TFTs with HfSiOx. gate dielectric exhibit excellent device performance in terms of higher I-ON/I-OFF current ratio, lower subthreshold swing, and lower threshold voltage (V-th) albeit with slightly higher OFF-state current. More importantly, the mobility of TFTs with HfSiOx gate dielectric is 1.7 times that of TFTs with conventional deposited-SiO2 gate dielectric.