Band alignment of atomic layer deposited SiO2 and HfSiO4 with β-Ga2O3. (14th June 2017)

• Record Type: Journal Article
• Authors: Carey, Patrick H.; Ren, Fan; Hays, David C.; Gila, Brent P.; Pearton, Stephen J.; Jang, Soohwan; Kuramata, Akito
• Is Part Of: Japanese journal of applied physics. Volume 56:Number 7(2017)
• Publication Date: 2017-06-14
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.56.071101
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: The valence band offset at both SiO2 /β-Ga2 O3 and HfSiO4 /β-Ga2 O3 heterointerfaces was measured using X-ray photoelectron spectroscopy. Both dielectrics were deposited by atomic layer deposition (ALD) onto single-crystal β-Ga2 O3 . The bandgaps of the materials were determined by reflection electron energy loss spectroscopy as 4.6 eV for Ga2 O3, 8.7 eV for Al2 O3 and 7.0 eV for HfSiO4 . The valence band offset was determined to be 1.23 ± 0.20 eV (straddling gap, type I alignment) for ALD SiO2 on β-Ga2 O3 and 0.02 ± 0.003 eV (also type I alignment) for HfSiO4 . The respective conduction band offsets were 2.87 ± 0.70 eV for ALD SiO2 and 2.38 ± 0.50 eV for HfSiO4, respectively.