Enhancement-mode atomic-layer thin In2O3 transistors with maximum current exceeding 2 A/mm at drain voltage of 0.7 V enabled by oxygen plasma treatment

In this Letter, enhancement-mode operation in devices with 1.5 nm atomic-layer thin In2O3 channels over a wide range of channel lengths down to 40 nm is demonstrated using an O2 plasma treatment at room temperature. Drain currents (ID) in excess of 2 A/mm at a drain-to-source bias (VDS) of 0.7 V are achieved in enhancement mode with significantly improved subthreshold swing down to near-ideal 65 mV/dec, suggesting that O2 plasma treatment is very effective at reducing bulk and interface defects. By using low-temperature O2 plasma, the fabrication process remains back-end-of-line compatible while enabling a clear route toward high-performance In2O3 transistors and circuitry.