Annealing Effects on the Band Alignment of ALD SiO2 on (InxGa1−x)2O3 for x = 0.25–0.74. (6th April 2020)

• Record Type: Journal Article
• Authors: Fares, Chaker; Xian, Minghan; Smith, David J.; McCartney, M. R.; Kneiß, Max; von Wenckstern, Holger; Grundmann, Marius; Tadjer, Marko; Ren, Fan; Pearton, S. J.
• Is Part Of: ECS journal of solid state science and technology. Volume 9:Number 4(2020)
• Publication Date: 2020-04-06
• Subjects: Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2162-8777/ab8364
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : The band alignment of Atomic Layer Deposited SiO2 on (Inx Ga1−x )2 O3 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 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 (In0.25 Ga0.75 )2 O3, −0.45 eV for (In0.42 Ga0.58 )2 O3, −0.40 eV for (In0.60 Ga0.40 )2 O3, and −0.35 eV (In0.74 Ga0.26 )2 O3 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 (Inx Ga1−x )2 O3 studied.