Impact of Channel Length on Performance of Single-Gate and Dual-Gate a-IGZO Thin Film Transistor

摘要

This paper discusses about the channel length (L) variation in the single-gate (S-G) and dual-gate (D-G) amorphous-indium-gallium-zinc-oxide-thin-film-transistor (a-IGZO TFT). The threshold voltage (Vth) parameter is a concerned electrical characteristic of the TFT which is taken in the account for the depth analysis of channel length. Threshold voltage changes negatively as channel length decreases from 25μm to 5μm with step size of 5μm, Furthermore, it is observed that for the $L <5mu{m}$, it will not show desired behavior because of the drain induced barrier lowering effect (DIBL) causing degradation in the behavior of device. Besides this, the comparison of both SG and DG a-IGZO TFT device performance is discussed in terms of threshold voltage, subthreshold voltage, trans-conductance, mobility and channel length. The significantly high performance is observed for D-G structure based device with a mobility of 3.655cm²/Vs, whereas, 0.08 cm²/Vs of S-G a-IGZO TFT for L=25μm. Henceforth, DG a-IGZO TFT shows superior behavior than SG a-IGZO TFT making it more robust for digital circuit applications.