Lateral Polarity Control in GaN Based on Selective Growth Procedure Using Carbon Mask Layers

Abstract

For nonlinear optical applications using GaN, periodic inversion of crystallographic orientation (polarity) is required in terms of quasi-phase matching. We have developed a novel procedure for designing polarity pattern in GaN using metalorganic chemical vapor deposition, and applied to fabrication of periodical polarity inverted GaN films. Patterning has been achieved in atmosphere, even without the etching process, by employing the selective growth procedure using carbon mask layers. The carbon mask layers, formed by laser-induced modification of an organic layer, can be removed, then subsequent nitridation of the re-exposed sapphire substrate enables N-face (-c) domain growth within a Ga-face (+c) film.