Nucleus and Spiral Growth of N-face GaN(000(1)over-bar) Obtained by Selective-Area Metalorganic Vapor Phase Epitaxy

Nucleus and spiral growth mechanisms of N-face GaN(000 (1) over bar) were studied in selective-area metalorganic vapor phase epitaxy. An almost step-free N-face GaN surface is obtained by nucleus growth within a selective area without screw-type dislocations, while growth spirals are induced by the spiral growth mode when screw-type dislocations exist. The growth mechanism of N-face GaN is consistently explained by a theoretical analysis [W. K. Burton, N. Cabrera, and F. C. Frank: Philos. Trans. R. Soc. London, Ser. A 243 (1951) 299]. The step and activation energies are estimated to be 2.1 J/m(2) and 2.15 eV, respectively. (C) 2013 The Japan Society of Applied Physics