Deposition of lanthanide oxides on GaN is investigated as a means to produce stable dielectric with good interface quality. Epitaxial growth of cubic 〈 111 〉 -oriented Sc2 O3 is observed on GaN  with a lattice mismatch of 7.2%, whereas La2O3 growth, with a lattice mismatch of ∼21%, results in a mixed phase epitaxial film comprised of the bixbyite and hexagonal allotropes. Substantial roughening accompanies this mixed phase film. By inserting a thin Sc2 O 3 interfacial layer between La2O3 and GaN and a Sc2 O3 capping layer, the crystal quality of the predominantly La2O3 layer is improved and the stack is stabilized against hydroxide formation under ambient conditions.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)