Morphological and microstructural stability of N-polar InAlN thin films grown on free-standing GaN substrates by molecular beam epitaxy
- Electronics Science and Technology Division, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington DC 20375 (United States)
- Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)
- Sotera Defense Solutions, 2200 Defense Hwy Suite 405, Crofton, Maryland 21114 (United States)
The sensitivity of the surface morphology and microstructure of N-polar-oriented InAlN to variations in composition, temperature, and layer thickness for thin films grown by plasma-assisted molecular beam epitaxy (PAMBE) has been investigated. Lateral compositional inhomogeneity is present in N-rich InAlN films grown at low temperature, and phase segregation is exacerbated with increasing InN fraction. A smooth, step-flow surface morphology and elimination of compositional inhomogeneity can be achieved at a growth temperature 50 °C above the onset of In evaporation (650 °C). A GaN/AlN/GaN/200-nm InAlN heterostructure had a sheet charge density of 1.7 × 10{sup 13 }cm{sup −2} and no degradation in mobility (1760 cm{sup 2}/V s) relative to 15-nm-thick InAlN layers. Demonstration of thick-barrier high-electron-mobility transistors with good direct-current characteristics shows that device quality, thick InAlN layers can be successfully grown by PAMBE.
- OSTI ID:
- 22489806
- Journal Information:
- Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Vol. 34, Issue 2; Other Information: (c) 2016 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0734-2101
- Country of Publication:
- United States
- Language:
- English
Similar Records
Wet chemical etching of AlN and InAlN in KOH solutions
Characterization of MBE-grown InAlN/GaN heterostructure valence band offsets with varying In composition