Study on ECR dry etching and selective MBE growth of AlGaN/GaN for fabrication of quantum nanostructures on GaN (0 0 0 1) substrates

This paper attempts to form AlGaN/GaN quantum wire (QWR) network structures on patterned GaN (0 0 0 1) substrates by selective molecular beam epitaxy (MBE) growth. Substrate patterns were prepared along h11 ¯20i- and h1 ¯10 0i-directions by electron cyclotron resonance assisted reactive-ion beam etching (ECR-RIBE) process. Selective growth was possible for both directions in the case of GaN growth, but only in the h11 ¯20i-direction in the case of AlGaN growth. A hexagonalQWRnetwork was successfully grown on a hexagonal mesa pattern by combining the h1 1 ¯20i-direction and two other equivalent directions. AFM observation confirmed excellent surface morphology of the grown network. A clear cathodoluminescence (CL) peak coming from the embedded AlGaN/GaN QWR structure was clearly identified.