Study of high-quality (11-22) semi-polar GaN grown on nanorod templates

Abstract

(11-22) semi-polar GaN overgrown on nanorod templates with different nanorod diameters has been systematically studied in terms of crystal quality, strain relaxation, wafer bowing and electrical properties. With increasing nanorod diameter from 300 to 827nm, the full width at half maximum (FWHM) of the X-ray rocking curve reduces from 0.20° to 0.15° along (1-100) direction and from 0.15° to 0.10° along (11-2-3) direction, respectively. The strain relaxation of the overgrown GaN layers has been significantly enhanced, leading to a reduction in wafer bowing from 0.0298 to 0.0091cm-1. The electron mobility in the overgrown GaN layers increases from 83 to 228cmV-1s-1 and from 52 to 124cmV-1s-1 along (1-100) and (11-2-3) directions, respectively.