Dielectric characterization of transparent epitaxial Ga2O3 thin film on n-GaN∕Al2O3 prepared by pulsed laser deposition

( 2 ¯ 01 ) -oriented β-Ga2O3∕GaN thin films were epitaxially grown by pulsed laser deposition. These films have the specific in-plane orientation, which was confirmed by φ scans of Ga2O3 (111) and (3¯11) reflections. When oxygen flow rate was increased, the surface morphologies and roughness of β-Ga2O3 drastically changed. The β-Ga2O3∕GaN structure showed a stable and sharp interface and uniform elemental distribution in depth. The dielectric constant and memory window of β-Ga2O3∕GaN were about 13.9 and 0.50V for oxygen flow rate of 5SCCM (SCCM denotes cubic centimeter per minute at STP).