High-performance polysilicon TFTs using stacked Pr₂ O₃/oxynitride gate dielectric

In this letter, we have developed, for the first time, a stacked Pr₂O₃/SiO_χN_y gate dielectric into low-temperature polysilicon (poly-Si) thin-film transistors (TFTs). A high-performance TFT device that has a high effective carrier mobility, a high driving current, a small subthreshold swing, and a high I_ON/I_OFF current ratio can be achieved. This phenomenon is attributed to the smooth Pr₂ O₃/poly-Si interface provided by the N₂O plasma treatment. The presence of the SiO_χ buffer layer also enhanced the electrical reliability of the Pr₂O₃ poly-Si TFT. All of these results suggest that a high-k Pr₂ O₃ gate dielectric prepared under the buffer layer is a good candidate for high-performance TFTs.