Preparation and characteristic study of Schottky diodes based on Ga2O3 thin films

This study uses atomic layer deposition (ALD) to grow Ga2O3 films on SiO2 substrates and investigates the influence of film thickness and annealing temperature on film quality. Schottky diode devices are fabricated based on the grown Ga2O3 films, and the effects of annealing temperature, electrode size, and electrode spacing on the electrical characteristics of the devices are studied. The results show that as the film thickness increases, the breakdown voltage of the fabricated devices also increases. A Schottky diode with a thickness of 240 nm can achieve a reverse breakdown voltage of 300 V. The film quality significantly improves as the annealing temperature of the film increases. At a voltage of 5 V, the current of the film annealed at 900°C is 64 times that of the film annealed at 700°C. The optimum annealing temperature for Ohmic contact electrodes is 450°C. At 550°C, the Ohmic contact metal tends to burn, and the performance of the device is reduced. Reducing the electrode spacing increases the forward current of the device but decreases the reverse breakdown voltage. Increasing the Schottky contact electrode size increases the forward current, but the change is not significant, and there is no significant change in the reverse breakdown voltage. The device also performs well at high temperatures, with a reverse breakdown voltage of 220 V at 125°C. © 2024, Beijing University of Posts and Telecommunications. All rights reserved.