Patterned sapphire substrate (PSS) has been used to improve both internal quantum efficiency (IQE) and light extraction efficiency (LEE) of GaN-based light-emitting diodes (LEDs). In this study, two kinds of periodic triangle pyramidal array PSSs were fabricated by wet etching. (1) "CPSS" was pyramid with a flat top c-plane, and (2) "OPSS" was pyramid with an oxide-covered top c-plane. It was found that the output power of OPSS was 29.0 mW, which was 6.2% higher than that of CPSS. This is because the GaN lateral growth area of OPSS was higher than that of CPSS. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3592876] All rights reserved.