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Large conduction band offset at SiO 2 /β‐Ga 2 O 3 heterojunction determined by X‐ray photoelectron spectroscopy
Author(s) -
Konishi Keita,
Kamimura Takafumi,
Wong Man Hoi,
Sasaki Kohei,
Kuramata Akito,
Yamakoshi Shigenobu,
Higashiwaki Masataka
Publication year - 2016
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201552519
Subject(s) - x ray photoelectron spectroscopy , heterojunction , analytical chemistry (journal) , materials science , band offset , semimetal , chemical vapor deposition , conduction band , band gap , valence band , optoelectronics , electron , chemistry , nuclear magnetic resonance , physics , chromatography , quantum mechanics
We evaluated the band offsets at the SiO 2 /β‐Ga 2 O 3 (010) interface by X‐ray photoelectron spectroscopy (XPS). Plasma chemical vapor deposition with a liquid tetraethyl orthosilicate source for SiO 2 was used to prepare an SiO 2 (40 nm)/Ga 2 O 3 sample and an SiO 2 (3 nm)/Ga 2 O 3 sample for XPS analyses. The bandgap of SiO 2 was determined to be 8.7 ± 0.2 eV. A large conduction band offset of 3.1 ± 0.2 eV and a corresponding valence band offset of 1.0 ± 0.2 eV were determined for the SiO 2 /Ga 2 O 3 interface. These results suggest that an SiO 2 gate insulator is favorable for Ga 2 O 3 field effect transistors operating under high temperatures.