High-Performance Poly-Si Thin-Film Transistor With High- ZrTiO4 Gate Dielectric

High-performance poly-Si thin-film transistors (poly-Si TFTs) with metal-induced laterally crystallized (MILC) poly-Si channel and high-k ZrTiO₄ (ZTO) gate dielectric are shown for the first time. The MILC poly-Si and ZTO dielectric showed smooth interface (~1.8 nm) with a low interfacial layer and 4.1 nm of effective-oxide thickness. The electrical performance of MILC poly-Si TFT with ZTO exhibited low threshold voltage of -0.5 V, steep subthreshold slope of 0.25 V/decade, high I_ON/I_OFF of 1.8 × 10⁷, and high field-effect mobility of 250 cm²/Vs. These characteristics correspond to the best performance of the poly-Si TFTs with high-k gate dielectric reported so far. Moreover, the driving current and field-effect mobility of poly-Si TFT with ZTO gate dielectric were ten times higher than that of poly-Si TFT with deposited-SiO₂ gate dielectric.