Current-confining structure of InGaN hexagonal microfacet lasers by selective incorporation of Mg during selective-area MOVPE

Abstract

The combination of patterned dry etching and selective-area regrowth by MOVPE enables us to fabricate the group III-nitride-based lasers of various shapes and sizes and to integrate these lasers on substrates. The vertical cavity mirrors are formed by selective-area regrowth of the dry-etched inclined facets. No growth occurs on the substrate surface exposed by dry etching. In this method, current-confining structures are self-organizing because of the change in Mg incorporation during the vertical facet formation. The selectively regrown Mg-doped GaN consisted of three regions by the regrowth of top, inclined, and vertical facet surfaces, respectively. These regions exhibited different contrast in scanning electron microscope observation and different cathodeluminescence spectra due to the difference in probability of Mg incorporation into them. This phenomenon was successfully applied to form current-confining structures of the lasers. These lasers lased at room temperature by pulsed current injection.