Low temperature deposition of Ga2O3 films on sapphire and epi-GaN substrates

Abstract

Ga2O3 films were deposited on non-polar sapphire and epi-GaN substrates at low temperature by MOCVD. The ε-Ga2O3 films, which were preferentially grown along the (0001) crystal plane family, were obtained on a-, r-plane sapphire and GaN substrates, and contained a certain polycrystalline component. On the m-plane sapphire substrate, a polycrystalline film containing α/β-Ga2O3 was obtained. The grain size and surface fluctuations on m-plane sapphire substrate were large, while the film on r-plane sapphire and GaN substrates had more uniform surface and the film on GaN substrate had the flattest surface. Optical analysis indicated that the best quality Ga2O3 film on these sapphire substrates was deposited on r-plane substrate. XRD showed that the Ga2O3 film on GaN substrate had better crystalline quality than that on a-plane sapphire substrate.