Fabrication of blue GaN light-emitting diodes by laser etching

GaN light-emitting diodes (LEDs) were fabricated using a 248 nm KrF excimer laser. Thick photoresist was used to form an etching mask to resist the strong laser irradiation and the unmasked top p-type GaN layer was removed effectively to reveal the bottom n-type GaN layer for the n-type contact. The etching rate of GaN film by laser irradiation and the morphology of the etched surface were studied by atomic force microscopy (AFM). Current-voltage (I-V) and photoluminescence (PL) characteristics of GaN LEDs fabricated by laser etching were measured and compared to those of LEDs fabricated by commercial inductively coupled plasma (ICP) etching. The performance of GaN LEDs fabricated by laser etching was comparable to that of LEDs fabricated by commercial ICP etching.