ABSTRACT
I. Introduction Lateral overgrowth of GaN-based materials using patterned silica masks has enabled significant advances in material quality, through dramatic reductions in defect density. Selective growth, upon which lateral overgrowth depends, also allows the design of novel structures, including arrays of hexagonal pyramids or prisms, if growth is stopped before features formed in the earliest growth stages have coalesced. Incorporation of InGaN quantum wells in the final stages of pyramid growth can lead to the formation of quantum dot arrays [1]. Selective growth also has important applications in the fabrication of field-emitter arrays and III-N microcavity devices [2,3]. Microring and microdisk devices have previously been fabricated by lithography and etching [4] but the selective growth approach potentially produces more efficient cavities due to smoother facet walls, untainted by process damage.
