| Since their introduction, the demand for GaN light emitting diodes (LEDs) has skyrocketed for applications in lighting and displays. For many of these applications, the directionality and low cost provided by resonant cavity LEDs (RCLEDs) and the yet unrealized GaN vertical cavity laser (VCSEL) are attractive.; These devices however—VCSELs in particular—require an extreme degree of precision in their fabrication in order to avoid any show-stopping losses. Unfortunately, the lack of a lattice matched substrate, the extreme resistivity of the p-doped layers, and the resistance of GaN to conventional wet etching, preclude taking some of the more common approaches (such as incorporating an epitaxial DBR) to making these devices.; This work discusses the research on development and optimization of technologies to overcome these inherent difficulties in device fabrication. We present a structure that incorporates two dielectric mirrors after flip-chip bonding and the removal of the original substrate. A transparent current spreading contact is used to overcome the resistivity of the p-GaN, although an alternative method of current confinement using ion implantation is also explored. The resulting RCLED allows us to more thoroughly analyze our design and make a prediction as to how much further the structures must be pushed before lasing threshold is realized. |
