Patent attributes
A semiconductor light emitting diode includes a semiconductor substrate, an epitaxial layer of n-type Group III nitride on the substrate, a p-type epitaxial layer of Group III nitride on the n-type epitaxial layer and forming a p-n junction with the n-type layer, and a resistive gallium nitride region on the n-type epitaxial layer and adjacent the p-type epitaxial layer for electrically isolating portions of the p-n junction. A metal contact layer is formed on the p-type epitaxial layer. Some embodiments include a semiconductor substrate, an epitaxial layer of n-type Group III nitride on the substrate, a p-type epitaxial layer of Group III nitride on the n-type epitaxial layer and forming a p-n junction with the n-type layer, wherein portions of the epitaxial region are patterned into a mesa and wherein the sidewalls of the mesa comprise a resistive Group III nitride region for electrically isolating portions of the p-n junction. In method embodiments disclosed, the resistive border is formed by forming an implant mask on the p-type epitaxial region and implanting ions into portions of the p-type epitaxial region to render portions of the p-type epitaxial region semi-insulating. A photoresist mask or a sufficiently thick metal layer may be used as the implant mask. In some method embodiments, a mesa is formed in the epitaxial region prior to implantation. During implantation, the epiwafer is mounted at an angle such that ions are implanted directly into the sidewalls of the mesa, thereby rendering portions of the mesa semi-insulating. The epiwafer may be rotated during ion implantation.
