Patent ID: 8008165

Claim:
A method of processing a nitride semiconductor wafer comprising steps of: rough-shaping an as-grown water by eliminating fringes of the wafer; shaping circumference of the wafer into a circle; gross-polishing a top surface and a bottom surface of the water by supplying a polishing liquid including colloidal silica powder, silicon carbide powder, alumina powder or diamond powder in a pressureless state for removing distortion and reducing roughness; fine-polishing the top surface and the bottom surface by supplying a liquid including an alkali, potassium peroxodisulfate and polishing powder to a polishing machine and irradiating the liquid with ultraviolet rays for raising smoothness of the top surface and the bottom surface; and obtaining a freestanding nitride semiconductor wafer having a circular shape of a diameter larger than 45 mm.