The band alignment of Atomic Layer Deposited SiO2on (InxGa1−x)2O3at varying indium concentrations is reported before and after annealing at 450 °C and 600 °C to simulate potential processing steps during device fabrication and to determine the thermal stability of MOS structures in high-temperature applications. At all indium concentrations studied, the valence band offsets (VBO) showed a nearly constant decrease as a result of 450 °C annealing. The decrease in VBO was −0.35 eV for (In0.25Ga0.75)2O3, −0.45 eV for (In0.42Ga0.58)2O3, −0.40 eV for (In0.60Ga0.40)2O3, and −0.35 eV (In0.74Ga0.26)2O3for 450 °C annealing. After annealing at 600 °C, the band alignment remained stable, with <0.1 eV changes for all structures examined, compared to the offsets after the 450 °C anneal. The band offset shifts after annealing are likely due to changes in bonding at the heterointerface. Even after annealing up to 600 °C, the band alignment remains type I (nested gap) for all indium compositions of (InxGa1−x)2O3studied.
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- ECS Journal of Solid State Science and Technology
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- Article No. 045001
- The Electrochemical Society
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- National Science Foundation
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