High-Performance and Low-Temperature-Compatible p-Channel Polycrystalline-Silicon TFTs Using Hafnium-Silicate Gate Dielectric

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 HfSiOxgate dielectric exhibit excellent device performance in terms of higher ION/IOFFcurrent ratio, lower subthreshold swing, and lower threshold voltage (Vth) albeit with slightly higher OFF-state current. More importantly, the mobility of TFTs with HfSiOxgate dielectric is 1.7 times that of TFTs with conventional deposited-SiO2gate dielectric.