【Device Papers】Ohmic contact to Schottky conversion on mitigating the oxygen defects present at the Ni/MgO-Ga₂O₃ interface

      Researchers from the Indian Institute of Technology Ropar have published a dissertation titled "Ohmic contact to Schottky conversion on mitigating the oxygen defects present at the Ni/MgO-Ga₂O₃ interface" in Journal of Physics D: Applied Physics.

Abstract

      Gallium oxide (Ga₂O₃) holds significant potential for next generation power devices with its intrinsic capability to hold high electric field than conventional semiconductor before its breakdown. However, the operation of Ga₂O₃-based power devices and figure-of-merit are significantly influenced by the quality of Metal-Ga₂O₃ contacts and interface defects. Here, we report influence of oxygen vacancy on the electronic properties of Ni/MgO-Ga₂O₃ metal-oxide-semiconductor interface. We explore the interface of Ga₂O₃ and a thin MgO layer with variable oxygen vacancies for schottky-barrier diodes (SBDs). The Ni/MgO-Ga₂O₃ stack with 0% oxygen flow during MgO growth offers a rather leaky (Ohmic) characteristic owing to the existence of oxygen defects at the Ni/MgO-Ga₂O₃ interface. However, MgO film with 66% oxygen flow during its growth, Ni/MgO-Ga₂O₃ SBD exhibits a rectifying behaviour as a result of the compensated oxygen vacancies. X-ray photo electron spectroscopy, frequencies dependent capacitance-voltage and conductance-voltage characteristics were analysed to elucidate the mechanisms of the transition from Ohmic to Schottky behaviour of the contact. This study paves the way for understanding and controlling interface defects which is essential for advancing the development of next-generation power electronics.

DOI：

https://doi.org/10.1088/1361-6463/adf233