Morphological and microstructural stability of N-polar InAlN thin films grown on free-standing GaN substrates by molecular beam epitaxy
Abstract
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 × 1013 cm−2 and no degradation in mobility (1760 cm2/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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 29, 2016
- Source ID
- 10.1116/1.4940759
Entities
People
- Brian P. Downey
- D. Scott Katzer
- David F. Storm
- David J Smith
- David J. Meyer
- Matthew T. Hardy
- Neeraj Nepal
- Thomas O. Mcconkie
Organizations
- Air Force Research Laboratory
- Arizona State University
- National Research Council
- Office of Naval Research
- United States Naval Research Laboratory