ZnO:(B, Ga)/Au electrodes for improved Ohmic contacts on ultrawide-bandgap Ga2O3 films

Gallium oxide (Ga 2 O 3 ) is an ultrawide-bandgap semiconductor material known for its high breakdown field strength , large Baliga's figure of merit, and significant thermal and chemical stability, making it suitable for advanced technological applications. In this paper, Ga 2 O 3 films were prepared using radio-frequency (RF) magnetron sputtering . B and Ga co-doped ZnO (BGZO)/Au composite electrodes were developed to achieve improved Ohmic contact characteristics with Ga 2 O 3 films, comparing these results with those of widely used Ti/Au electrodes. The specific contact resistance of the electrodes was quantitatively measured using the dot circular transmission line model (d-CTLM) method. The results indicate that the presence of BGZO intermediate semiconductor layers (ISL) with appropriate thickness effectively reduces the specific contact resistance between the electrode and the Ga 2 O 3 film, and the minimum specific contact resistance value is 1.049 × 10 −2 Ω·cm 2 . This research provides critical insights into optimizing electrode to enhance the performance and reliability of Ga 2 O 3 -based devices. • Improved Ohmic contacts on Ga 2 O 3 films using ZnO:(B, Ga)/Au electrodes • Accurately measured specific contact resistance of electrode with d-CTLM method • Lowest specific contact resistance of 1.049 × 10 −2 Ω·cm 2 was achieved. • Enhanced electrode performance due to BGZO intermediate semiconductor layer