Mobility improvement of HfO₂ LTPS TFTs with nitrogen implantation

In this paper, we demonstrate the low-temperature polycrystalline silicon thin-film transistors (LTPS-TFTs) with high-k HfO₂ gate dielectric and nitrogen implantation to achieve high-performance characteristics for the first time. Various nitrogen does 5 × 10¹³ and 5 × 10¹⁴cm^-2 were implanted after gate dielectric deposition. Significant improvement 94. 4% and 74.4% on transconductance Gm and field effect mobility, respectively, are observed due to the nitrogen implantation. In addition, a substantial gate leakage current reduction over four orders is also obtained to decrease undesirable power dissipation. Finally, a high performance LTPS-TFT with low subthreshold swing 0. 177 V/decade and threshold voltage about 1 V can be achieved without any other hydrogen plasma passivation treatments.