Ultrathin In 2 O 3 thin-film transistors deposited from trimethylindium and ozone

Indium oxide (In O ) 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 In O films and fabricate ultrathin In O TFTs. The In O TFTs 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 In O TFTs exhibit short channel effect, it can be improved by adding an ALD Ga O capping layer to afford the bilayer In O /Ga O channel structure. The afforded In O /Ga O TFTs exhibit improved immunity to the short channel effect, with good TFT characteristics of / of 10 , of 9.3cm2V-1s-1, and positive of 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.