Nonpolar GaN grown on Si by hydride vapor phase epitaxy using anodized Al nanomask

GaN growth by the hydride vapor phase technique on (100) Si substrates masked by porous Al anodic oxide is described. The masks were prepared by vacuum deposition of Al with subsequent anodic oxidation in dilute sorrel acid. The grown GaN layer is nonpolar, with ( 11 2 ¯ 0 ) a -orientation and a full width at half maximum of the ( 11 2 ¯ 0 ) reflection below 500 arc sec and showing small anisotropy. This result is comparable with the results obtained for a -GaN growth using selective epitaxy or advanced buffer growth routines. Microcathodoluminescence spectra of the grown films confirm a low density of stacking faults. Possible growth mechanisms are discussed.