Electrical Properties of Thermally Annealed β-Ga2O3 Metal-Semiconductor Field-Effect Transistors with Pt/Au Schottky Contacts

The electrical properties of the metal-semiconductor field-effect transistors (MESFETs) based on quasi-two-dimensional β-Ga 2 O 3 n-channel and Pt/Au Schottky gate electrode were analyzed with cumulative temperature and time of thermal annealing. Mechanical exfoliation was used to prepare the β-Ga 2 O 3 microflakes and the fabricated device was thermally annealed using either a rapid thermal annealing (RTA) equipment or a furnace. Raman spectroscopy was also employed to investigate the robustness of the mechanically exfoliated β-Ga 2 O 3 microflakes. The devices survived a high temperature up to 700°C (RTA) and endured thermal annealing for an extended time of 90 minutes at 500°C. The stable performance was observed from the β-Ga 2 O 3 MESFET until the Schottky barrier height decreased substantially and the current modulation deteriorated significantly after an RTA at 700°C. The obvious …