Heteroepitaxial VO{sub 2} thin films on GaN: Structure and metal-insulator transition characteristics
- Harvard School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States)
Monolithic integration of correlated oxide and nitride semiconductors may open up new opportunities in solid-state electronics and opto-electronics that combine desirable functional properties of both classes of materials. Here, we report on epitaxial growth and phase transition-related electrical properties of vanadium dioxide (VO{sub 2}) thin films on GaN epitaxial layers on c-sapphire. The epitaxial relation is determined to be (010){sub vo{sub 2}} parallel (0001){sub GaN} parallel (0001){sub A1{sub 2O{sub 3}}} and [100]{sub vo{sub 2}} parallel [1210]{sub GaN} parallel [0110]{sub A1{sub 2O{sub 3}}} from x-ray diffraction. VO{sub 2} heteroepitaxial growth and lattice mismatch are analyzed by comparing the GaN basal plane (0001) with the almost close packed corrugated oxygen plane in vanadium dioxide and an experimental stereographic projection describing the orientation relationship is established. X-ray photoelectron spectroscopy suggests a slightly oxygen rich composition at the surface, while Raman scattering measurements suggests that the quality of GaN layer is not significantly degraded by the high-temperature deposition of VO{sub 2}. Electrical characterization of VO{sub 2} films on GaN indicates that the resistance changes by about four orders of magnitude upon heating, similar to epitaxial VO{sub 2} films grown directly on c-sapphire. It is shown that the metal-insulator transition could also be voltage-triggered at room temperature and the transition threshold voltage scaling variation with temperature is analyzed in the framework of a current-driven Joule heating model. The ability to synthesize high quality correlated oxide films on GaN with sharp phase transition could enable new directions in semiconductor-photonic integrated devices.
- OSTI ID:
- 22089481
- Journal Information:
- Journal of Applied Physics, Vol. 112, Issue 7; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CRYSTAL DEFECTS
DEPOSITION
ELECTRIC CONDUCTIVITY
EPITAXY
GALLIUM NITRIDES
JOULE HEATING
LAYERS
PHASE TRANSFORMATIONS
RAMAN EFFECT
RAMAN SPECTRA
SEMICONDUCTOR MATERIALS
SPUTTERING
SURFACES
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
VANADIUM OXIDES
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY