Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1794382 | Journal of Crystal Growth | 2009 | 5 Pages |
Abstract
Growth and characterization of ammonia-based metal-organic molecular beam epitaxy (NH3-MOMBE) AlxGa1âxN epitaxial films has been conducted. AlxGa1âxN films spanning the entire range of aluminum compositions were grown on GaN templates. This is the first reported successful growth of AlxGa1âxN via NH3-MOMBE, using triethylgallium (TEGa), triethylaluminum (TEAl) and ammonia (NH3) as the precursors. These films were characterized via optical interferometry (OI), atomic force microscopy (AFM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). High-quality AlxGa1âxN films, as inferred by XRD, are achievable in films without cracking. The catalytic effect of Al on NH3 is found to play a major part in the growth rate of the AlxGa1âxN films. The excessive nitrogen produced through this catalytic effect hinders the growth rate at lower Al composition while increasing the growth rate of AlxGa1âxN (x>0.4) films. Stress in the deposited films is found to be partially relieved through surface cracking along the ã1 1 2¯ 0ã direction in the film. These cracks provide dislocation gettering centers, with the dislocation pit density decreasing with increasing Al composition. A basic understanding on the factors affecting the growth of AlxGa1âxN is determined and will become the basis for further investigations into the optimization of AlxGa1âxN growth.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Daniel Billingsley, Walter Henderson, David Pritchett, W. Alan Doolittle,