Changes in valence band offsets (VBOs) as a result of annealing of heterostructures of atomic layer deposited Al2O3 on (InxGa1 - x)2O3 (where x = 0.25-0.75), grown by pulsed laser deposition, are reported. The heterostructures have been annealed at 600 °C to simulate the expected thermal budget during device fabrication. The VBOs decrease significantly as a result of annealing, with the change being larger at higher indium concentrations. The decrease in VBO ranges from -0.38 eV for (In0.25Ga0.75)2O3 to -1.28 eV for (In0.74Ga0.26)2O3 and is likely due to increased interfacial disorder at the heterointerface as well as phase differences between gallium-rich samples and indium-rich samples. After annealing, the band alignment remains type I (nested gap) for x = 0.25, 42, and 60 but becomes type II for the (In0.74Ga0.26)2O3 sample.
ASJC Scopus subject areas
- Physics and Astronomy(all)