Strategies for High-Performance Amorphous Indium–Gallium–Zinc Oxide Schottky Contact via Defect-Induced Physical Interface Modification

The research on amorphous indium–gallium–zinc oxide (IGZO) Schottky contacts has received much attention for various electronic applications due to their high uniformity, excellent electrical properties, and large band gap. However, noble metal/IGZO Schottky contact is often challenged by chemical reaction at the interface between the noble metal and IGZO. Herein, we present a strategy to form the Schottky barrier via a defect-induced physical interface modification (DIPIM) process using defect engineering of the insulator. We show that high-quality IGZO can be formed for high-performance Schottky contact without chemical reaction by inserting defect-induced Al2O3 between Pd and IGZO. DIPIM ensures an oxygen-rich environment in IGZO at the Pd/IGZO interface, reducing the level of oxygen vacancy defects and suppressing the In metal reduction. Using this process, we improved the Pd/IGZO Schottky characteristics such as the high rectifying ratio by suppressing the leakage current. Furthermore, the Schottky barrier is consistent with the theoretical value of the Schottky–Mott relationship. We believe that this strategy not only provides a suitable platform for high-performance IGZO Schottky contact by preventing the chemical interaction between the noble metal and IGZO but also accelerates the development of practical IGZO Schottky contact application devices.