Novel symmetry in the growth of gallium nitride on magnesium aluminate substrates
- Center for Space Microelectronics Technology, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)
- APA Optics, Inc., Blaine, Minnesota 55449 (United States)
- Department of Materials Science, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)
The growth of GaN by metalorganic chemical vapor deposition on (111) and (100) magnesium aluminate (MgAl{sub 2}O{sub 4}) substrates is examined using transmission electron microscopy. The results indicate that mainly wurtzite GaN is grown for both orientations. On the (111) substrate the following epitaxial relationship is observed: (0001)GaN {parallel} (111)MgAl{sub 2}O{sub 4}, and [11{bar 2}0]GaN {parallel} [1{bar 1}0]MgAl{sub 2}O{sub 4}. During the early stages of the (100) growth, four orientations of the wurtzite phase and a zinc-blende phase are formed. With increasing thickness, one of the wurtzite orientations dominates, with the epitaxial relationship being (1{bar 1}01)GaN {parallel} (100)MgAl{sub 2}O{sub 4} and the [11{bar 2}0]GaN nearly parallel to [011]MgAl{sub 2}O{sub 4}. This choice of growth orientation appears to be determined primarily by the nature of the interfacial bonding, with the basal plane of each of the four wurtzite GaN variants being nearly aligned along one of the four {l_brace}111{r_brace} planes intersecting the (100) surface of the MgAl{sub 2}O{sub 4}. {copyright} {ital 1996 American Institute of Physics.}
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 277174
- Journal Information:
- Applied Physics Letters, Vol. 68, Issue 3; Other Information: PBD: Jan 1996
- Country of Publication:
- United States
- Language:
- English
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