Improving the Gate-Induced Drain Leakage and On-State Current of Fin-Like Thin Film Transistors with a Wide Drain

Polycrystalline silicon (poly-Si) thin film transistors (TFT) with a tri-gate fin-like structure and wide drain were designed and simulated to improve gate-induced drain leakage (GIDL), ON-state current, and breakdown voltage. The GIDL of fin-like TFTs (FinTFTs) examined in this study was dominated by longitudinal band-to-band tunneling (L-BTBT). Extending the wide drain can effectively suppress the longitudinal electric field near the drain and improve L-BTBT GIDL and breakdown. In addition, a wider drain can lead to a large cross section in the current path and improve the ON-state current. FinTFTs with wide drain exhibit a low GIDL, a high ON-state current, and high breakdown voltage, while maintaining favorable gate controllability.