Low-temperature growth of Ga2O3 thin films on Si substrates by metal organic chemical vapor deposition and their electrical characteristics

Abstract

In this paper, Ga2O3 thin films were grown on n-type Si substrates at various growth temperatures of 500, 550, 600, 650, and 700 °C. The Ga2O3 thin films grown at 500 and 550 °C were characterized by featureless flat surfaces. Films grown at higher temperatures of 600, 650, and 700 °C showed a very rough surface morphology. To determine the effect of annealing on the thin films grown at relatively low temperatures (500, 550, 600, 650, and 700 °C), the Ga2O3 films were thermally treated at 900 °C for 10 min. The crystal structure of the Ga2O3 films grown at 500 and 550 °C changed from amorphous to polycrystalline with a flat surface. The Ga2O3 film grown at 550 °C was chosen for the fabrication of a Schottky barrier diode, whose electrical properties were evaluated before and after thermal treatment. A metal–semiconductor–metal-type photodetector was fabricated using a Ga2O3 thin film grown at low temperatures, whose photocurrent under 266-nm UV illumination wavelength was 5.32 times higher than the dark current under an operating voltage of 10 V.