Heterostructures of Atomic Layer Deposited SiO2 on thin layers of (AlxGa1-x)2O3 with x = 0.2 - 0.65 deposited by Pulsed Laser Deposition were annealed at 600°C to simulate ohmic contact formation in MOS devices. The valence band offsets decrease significantly as a result of this annealing, with the change dependent on the initial Al composition. The decrease ranges from 0.65 eV for (Al0.20Ga0.80)2O3 to 1.75 eV for (Al0.65Ga0.35)2O3 and is likely due to an increase in interfacial disorder as a result of annealing. Concurrently, the conduction band offsets increase, improving carrier confinement for electrons within the heterostructure. The band alignment remains type I (nested gap) across the entire composition range examined.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials