In this study, we demonstrated the band alignment between a BeO and AlGaN/GaN heterointerface. The bandgap of the BeO film was measured to be 8.2 ± 0.05 eV by reflection electron energy loss spectroscopy. A valence band offset of the BeO/AlGaN interface was determined to be 1.1 ± 0.1 eV by X-ray photoelectron spectroscopy. Based on the spectral analysis result, the conduction band offset was calculated to be 3.2 ± 0.1 eV. When BeO was used as the gate dielectric of an AlGaN/GaN transistor, the on/off current ratio was improved to 107. The results of the band alignment and electrical testing open up opportunities for the application of BeO films to the gate dielectric of GaN-based high-power devices.
Bibliographical noteFunding Information:
This research was supported by Korea Electric Power Corporation (Grant number3): R18XA06-03 and by the Ministry of Science and ICT (MSIT), Korea , under the ICT Consilience Creative Program ( IITP-2019-2017-0-01015 ) supervised by the Institute for Information & Communications Technology Promotion (IITP) . CWB, JHY, and ESL are grateful to the Institute for Basic Science (IBS-R019) as well as the BK21 Plus Program funded by the Ministry of Education and the National Research Foundation of Korea for their support.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films