Method for fabricating light emitting device including photonic crystal structures

A method for fabricating a light emitting device (LED), comprising:

• forming a light emitting structure on a sapphire substrate, wherein the light emitting structure comprises a first conductivity type semiconductor layer having Ga material and Nitride material on the sapphire substrate, an active layer on the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer on the active layer;
• and
• removing the sapphire substrate from the first conductivity type semiconductor layer by a laser lift-off process;
• forming a mixed-period photonic crystal structure on the first conductivity type semiconductor layer after the removing of the sapphire substrate;
• wherein the forming of the mixed-period photonic crystal structure comprises forming a first, a second, and a third photonic crystal structures having respective a first, a second, and a third periods,
• wherein the first photonic crystal structure is formed by a dry etching process using a first pattern on the first conductivity type semiconductor layer,
• wherein the second photonic crystal structure and the third photonic crystal structure are formed by a wet etching process after removing the first pattern,
• wherein the first photonic crystal structure comprises a concave region and a convex region,
• wherein the second photonic crystal structure is formed on the concave region of the first photonic crystal structure,
• wherein the third photonic crystal structure is formed on the convex region of the first photonic crystal structure, and
• wherein the Ga material is accumulated at a top surface of the first conductivity type semiconductor layer during the removing of the sapphire substrate by the laser lift-off process to interrupt the wet etching process.