Pendeo-epitaxial growth and characterization of gallium nitride and related materials

Abstract

Monocrystalline GaN and AlxGa1-xN films have been grown via the pendeo-epitaxy (PE)(1) technique with and without Si3N4 masks on GaN/AIN/6H-SiC(0001) and GaN(0001)/AIN(0001)/3C-SiC(111)/Si(111) substrates using organometallic vapor phase deposition. 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 were reduced at least five orders of magnitude relative to the initial GaN seed layers. Tilting to 0.2 degrees in the portion of the coalesced GaN epilayers grown over the silicon nitride masks was observed via X-ray diffraction. Neither tilting nor low angle boundaries were observed within areas of coalescence in the material grown on substrates without the masks.