Band alignment of atomic layer deposited SiO2 on (010) (Al0.14Ga0.86)2O3
Abstract
The (AlxGa1−x)2O3/Ga2O3 system is attracting attention for heterostructure field effect transistors. An important device design parameter is the choice of gate dielectric on the (AlxGa1−x)2O3 and its band alignment at the heterointerface. The valence band offset at the SiO2/(Al0.14Ga0.86)2O3 heterointerface was measured using x-ray photoelectron spectroscopy. The SiO2 was deposited by atomic layer deposition (ALD) onto single-crystal β-(Al0.14Ga0.86)2O3 grown by molecular beam epitaxy. The bandgap of the SiO2 was determined by reflection electron energy loss spectroscopy as 8.7 eV, while high resolution XPS data of the O 1s peak and onset of elastic losses were used to establish the (Al0.14Ga0.86)2O3 bandgap as 5.0 eV. The valence band offset was determined to be 1.60 ± 0.40 eV (straddling gap, type I alignment) for ALD SiO2 on β-(Al0.14Ga0.86)2O3. The conduction band offset was 2.1 ± 0.08 eV, providing for a strong electron transport restriction.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 30, 2018
- Source ID
- 10.1116/1.5052620
Entities
People
- B. P. Gila
- Chaker Fares
- David C. Hays
- Eric Lambers
- F. Ren
- S. J. Pearton
Organizations
- Defense Threat Reduction Agency
- University of Florida