Electrical properties, structural properties, and deep trap spectra of thin α-Ga2O3 films grown by halide vapor phase epitaxy on basal plane sapphire substrates
Abstract
Undoped epitaxial films of α-Ga2O3 were grown on basal plane sapphire substrates by halide vapor phase epitaxy (HVPE) in three different modes: standard HVPE, HVPE with constant flow of Ga and pulsed supply of O2 (O2-control growth regime), and with constant flow of O2 and pulsed delivery of Ga (Ga-control growth fashion). The best crystalline quality as judged by x-ray symmetric and asymmetric reflection half-widths and by atomic force microscopy morphology profiling was obtained with the O2-control deposition, and these results appear to be the best so far reported for α-Ga2O3 films. All grown α-Ga2O3 epilayers were high-resistivity n-type, with the Fermi level pinned near Ec − 1 eV deep traps. Photoinduced current transient spectra also showed the existence in standard HVPE samples and samples grown under the O2-control pulsed growth conditions of deep hole traps with levels near Ev + 1.4 eV whose density was suppressed in the Ga-control pulsed HVPE samples. The levels of the dominant deep traps in these α-Ga2O3 samples are close to the position of dominant electron and hole traps in well documented β-Ga2O3 crystals and films.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 01, 2018
- Source ID
- 10.1063/1.5075718
Entities
People
- A. Y. Polyakov
- Dae‐Woo Jeon
- Hoki Son
- I. V. Shchemerov
- In‐Hwan Lee
- Jonghee Hwang
- N. B. Smirnov
- Stephen Pearton
- А. I. Kochkova
- А. В. Черных
Organizations
- Defense Threat Reduction Agency
- Korea University
- Ministry of Education and Science of the Russian Federation
- National Research Foundation of Korea
- National University of Science and Technology
- University of Florida