High-performance p-channel LTPS-TFT using HfO₂ gate dielectric and nitrogen ion implantation

In this communication, a high-performance p-channel low-temperature poly-Si thin-film transistor with HfO₂ gate dielectric and nitrogen ion implantation is demonstrated for the first time. A low threshold voltage V _TH = -0.8 V, excellent subthreshold swing S.S. = 0.123 V/decade, high field effect mobility μ_FE = 64.14 cm² V^-1 s^-1 and high driving current I_Dsat = 9.14 νA νm ^-1 @ 3 V operation voltage of the p-channel LTPS-TFT can be achieved. The high performance characteristics are attributed to the very low effective oxide thickness EOT = 8.4 nm provided by the HfO₂ gate dielectric and the passivation of effective interface states and grain boundary traps by the nitrogen ion implantation treatment. It would be very suitable for the application of a high-speed and low-power pixel-driving device in flat-panel displays.