Robert F. Davis, Thomas Gehrke
North Carolina State University
Kevin J. Linthicum
Nitronex Corporation
Tsvetanka S. Zheleva
North Carolina State University
Pradeep Rajagopal
Nitronex Corporation
Christian A. Zorman, Mehran Mehregany
Case Western Reserve University
This article was presented as part of Symposium W, "Gallium Nitride and Related Alloys" at the 1999 Fall Meeting of the Materials Research Society held in Boston, Massachusetts, November 28-December 3
Discrete and coalesced monocrystalline GaN and AlxGa1-xN layers grown via Pendeo-epitaxy (PE) originated from side walls of GaN seed structures containing SiNx top masks have been grown via organometallic vapor phase deposition on GaN/AlN/6H-SiC( 0001) and GaN(0001)/AlN(0001)/3C-SiC(111)/Si(111) substrates. Scanning and transmission electron microscopies were used to evaluate the external microstructures and the distribution of dislocations, respectively. The dislocation densities in the PE grown films was reduced by at least five orders of magnitude relative to the initial GaN seed layers. Tilting in the coalesced GaN epilayers was observed via X-ray diffraction. A tilt of 0.2° was confined to areas of mask overgrowth; however, no tilting was observed in the material suspended above the SiC substrate. The strong, low-temperature PL band-edge peak at 3.45 eV with a FWHM of 17 meV was comparable to that observed in PE GaN films grown on 6H-SiC(0001). The band-edge in the GaN grown on AlN(0001)/SiC(111)Si(111) substrates was shifted to a lower energy by 10 meV, indicative of a greater tensile stress.
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Cite this article as: MRS Internet J. Nitride Semicond. Res. 5S1, W2.1 (2000).
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