The band alignment of Atomic Layer Deposited SiO2 on (InxGa1-x)2O3 at 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 higherature 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)2O3 for 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)2O3 studied.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials