Fabrication of two-dimensional photonic crystal patterns on GaN-based light-emitting diodes using thermally curable monomer-based nanoimprint lithography

The fabrication process of photonic crystals in a p-GaN layer was established to improve the light extraction efficiency of light-emitting diodes (LEDs) by using nanoimprint lithography and inductively coupled plasma (ICP) etching process. Due to low etch selectivity of imprinted pattern, Cr mask patterns were lifted-off from the p-GaN surface and ICP etch process was followed using Si Cl4 -based plasma. As a result, two-dimensional pillar array patterns were uniformly fabricated on the p-GaN layer and the photoluminescence intensity of the photonic crystal patterned LED was increased by 2.6 fold compared to that of the same LED sample without photonic crystal patterns.