Impacts of N₂ and NH₃ Plasma Surface Treatments on High-Performance LTPS-TFT With High-κ Gate Dielectric

Low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs) with high- kappa gate dielectrics and plasma surface treatments are demonstrated for the first time. Significant field-effect mobility muFEimprovements of ~ 86.0% and 112.5% are observed for LTPS-TFTs with HfO2gate dielectric after N2and NH3plasma surface treatments, respectively. In addition, the N2and NH3plasma surface treatments can also reduce surface roughness scattering to enhance the field-effect mobility muFEat high gate bias voltageVG, resulting in 217.0% and 219.6% improvements in driving current, respectively. As a result, high-performance LTPS-TFT with low threshold voltageVTH~ 0.33 V, excellent subthreshold swing S.S. ~ 0.156 V/decade, and high field-effect mobility muFE~ 62.02 cm2V middots would be suitable for the application of system-on-panel.