Thermal stability of band offsets of NiO/GaN

NiO is a promising alternative to p-GaN as a hole injection layer for normally-off lateral transistors or low on-resistance vertical heterojunction rectifiers. The valence band offsets of sputtered NiO on c-plane, vertical geometry homoepitaxial GaN structures were measured by x-ray photoelectron sp...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of vacuum science & technology. A, Vacuum, surfaces, and films Vacuum, surfaces, and films, 2022-09, Vol.40 (5)
Hauptverfasser: Xia, Xinyi, Li, Jian-Sian, Chiang, Chao-Ching, Yoo, Timothy Jinsoo, Ren, Fan, Kim, Honggyu, Pearton, S. J.
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:NiO is a promising alternative to p-GaN as a hole injection layer for normally-off lateral transistors or low on-resistance vertical heterojunction rectifiers. The valence band offsets of sputtered NiO on c-plane, vertical geometry homoepitaxial GaN structures were measured by x-ray photoelectron spectroscopy as a function of annealing temperatures to 600 °C. This allowed determination of the band alignment from the measured bandgap of NiO. This alignment was type II, staggered gap for both as-deposited and annealed samples. For as-deposited heterojunction, ΔEV = 2.89 eV and ΔEC = −2.39 eV, while for all the annealed samples, ΔEV values were in the range of 3.2–3.4 eV and ΔEC values were in the range of −(2.87–3.05) eV. The bandgap of NiO was reduced from 3.90 eV as-deposited to 3.72 eV after 600 °C annealing, which accounts for much of the absolute change in ΔEV − ΔEC. At least some of the spread in reported band offsets for the NiO/GaN system may arise from differences in their thermal history.
ISSN:0734-2101
1520-8559
DOI:10.1116/6.0002033