Ultrathin InOthin-film transistors deposited from trimethylindium and ozone.

Indium oxide (InO) is a promising channel material for thin-film transistors (TFTs). In this work, we develop an atomic layer deposition (ALD) process of using trimethylindium and ozone (O) to deposit InOfilms and fabricate ultrathin InOTFTs. The InOTFTs with 4 nm channel thickness show generally good switching characteristics with a high/of 10, a high mobility () of 16.2cm2V-1s-1and a positive threshold voltage () of 0.48 V. Although the 4 nm InOTFTs exhibit short channel effect, it can be improved by adding an ALD GaOcapping layer to afford the bilayer InO/GaOchannel structure. The afforded InO/GaOTFTs exhibit improved immunity to the short channel effect, with good TFT characteristics of/of 10,of 9.3cm2V-1s-1, and positiveof 2.23 V. Overall, the thermal budget of the entire process is only 400 °C, which is suitable for the display and CMOS back-end-of-line-compatible applications.