The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. Etched features, such as truncated pyramids, may be formed on the emitting surface, prior to the RIE process, by cutting into the surface using a saw blade or...http://www.google.se/patents/US7534633?utm_source=gb-gplus-sharePatent US7534633 - LED with substrate modifications for enhanced light extraction and method of making same
