Atomic structure analysis of gallium oxide at the Al<sub>2</sub>O<sub>3</sub>/GaN interface using photoelectron holography
Mutsunori Uenuma, Shingo Kuwaharada, Hiroto Tomita, Masaki Tanaka, Zexu Sun, Yusuke Hashimoto, Mami N. Fujii, T. Matsushita, Yukiharu Uraoka
Abstract
Abstract The atomic structure of gallium oxide at the Al 2 O 3 /GaN interface was investigated using photoelectron holography. An amorphous Al 2 O 3 layer was formed on a homoepitaxially grown n-type GaN surface by atomic layer deposition at 300 °C. The photoelectron holograms were measured by a display-type retarding field analyzer. From the forward-focusing peaks in the photoelectron hologram of Ga 3d, we confirmed that a layer of gallium oxide ordered structure is found at the Al 2 O 3 /GaN interface, and the Ga–O–Ga lattice constant on the c -axis was 1.2 times longer than the Ga–N–Ga distance of the GaN crystal structure.