The use of lateral overgrowth techniques to develop III-nitride microcaviti
es with both mirrors fabricated from very highly reflecting dielectric mult
ilayers (e.g. SiO2/ZrO2) will be discussed. Multilayer mirror stacks with b
road high reflectivity stop-bands and peak reflectivities in excess of 99%
at wavelengths near the emission energies of typical InGaN/GaN quantum well
structures, have been patterned in order to be compatible with subsequent
lateral epitaxial overgrowth or pendeoepitaxy. Improvements in material qua
lity resulting from lateral overgrowth above single layer masks are demonst
rated using spatially resolved photoluminescence and cathodoluminescence im
aging.