Highly selective growth of GaN on 4H-SiC using the SiC substrate as a pseudomask has been demonstrated using the ammonia molecular-beam-epitaxy technique. A total lack of nucleation on the bare SiC surface was observed under typical GaN growth conditions. The nucleation of the GaN layer occurred preferentially from a patterned thin (300 A) AlN seed layer, which had been predeposited on the SiC surface using the magnetron-sputter-epitaxy technique and patterned into parallel stripes by photolithography and chemically assisted ion-beam etching. Evidence of lateral overgrowth was observed by scanning electron microscopy and x-ray diffraction studies. The GaN stripes grown show extremely smooth side facets due to the lateral growth.
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