Amorphous InGaZnO Thin-Film Transistors With Sub-10-nm Channel Thickness and Ultrascaled Channel Length

We investigate the effect of channel layer thickness on effective mobility (mu(eff)) in the sub-10-nm regime of amorphous indium-gallium-zinc-oxide thin-film transistors (alpha-IGZO TFTs). TFT devices with extremely scaled channel thickness t(alpha-)(IGZO) of 3.6 nm were realized, exhibiting low subthreshold swing (SS) of 74.4 mV/decade and the highest effective mobility mu(eff) of 34 cm(2)/V.s at a carrier density N-carrier of similar to 5 x 10(12) cm(2) for any kind of alpha-IGZO TFTs having sub-10-nm t(alpha-)(IGZO). No significant degradation of mu(eff)( )is observed as alpha-IGZO thickness reduced from 6 to 3.6 nm. By scaling down the channel length L-CH to 38 nm, high extrinsic transconductance (G(m,max)) of 125 mu S/mu m (at V-DS of 1 V) and oN-state current I-ON of 350 mu A/mu m at V-GS-V-T of 3 V with V-DS of 2.5 V are achieved.

Automated summary

The study found that in the sub-10-nm regime, TFT devices with a channel thickness of 3.6 nm can achieve low subthreshold swing and the highest effective mobility. The effective mobility does not degrade significantly as the alpha-IGZO thickness is reduced from 6 to 3.6 nm.