Amorphous IGZO TFTs featuring Extremely-Scaled Channel Thickness and 38 nm Channel Length: Achieving Record High G_m.max of 125 μ S/μm at VDS of 1 V and ION of 350 μA/μm

摘要

We demonstrated amorphous indium-gallium-zinc-oxide thin film transistors (a- IGZO TFTs) with extremely scaled channel thickness $t_{a-IGZO}$ of 3.6 nm, achieving low SS of74.4 mV/decade and the highest $mu_{eff}$ of34 cm2/V·s at carrier density $N_{carrier}$ of ~5 × 1012 cm-2 for a-IGZO TFTs having sub-10 nm $t_{lpha-IGZO}$. We found that there is no obvious degradation of mobility as $t_{lpha-IGZO}$ changes from 6 nm to 3.6 nm. By scaling down the channel length $L_{CH}$ to 38 nm, the devices have shown the highest extrinsic transconductance $G_{m}$ of 125 $mumathrm{S}/mumathrm{m}$ l (at $V_{DS}$ of 1 V) and the highest on-state current ION of 350 $mu mathrm{A}/mu mathrm{m}$ at VGS-VT of3.0 Vand $V_{DS}$ of 2.5 V for any kind of a-IGZO TFTs.