Impacts of N-2 and NH3 Plasma Surface Treatments on High-Performance LTPS-TFT With High-kappa Gate Dielectric

Abstract

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 mu(FE) improvements of similar to 86.0% and 112.5% are observed for LTPS-TFTs with HfO2 gate dielectric after N-2 and NH3 plasma surface treatments, respectively. In addition, the N2 and NH3 plasma surface treatments can also reduce surface roughness scattering to enhance the field-effect mobility mu(FE) at high gate bias voltage V-G, resulting in 217.0% and 219.6% improvements in driving current, respectively. As a result, high-performance LTPS-TFT with low threshold voltage V-TH similar to 0.33 V, excellent subthreshold swing S.S. similar to 0.156 V/decade, and high field-effect mobility mu(FE) similar to 62.02 cm(2) /V . s would be suitable for the application of system-on-panel.