GALLIUM NITRIDE-BASED COMPOUND SEMICONDUCTOR SUBSTRATE AND METHOD OF PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a gallium nitride-based compound semiconductor substrate almost free from pits and excellent in surface flatness. SOLUTION: The number of pits and scratch lines on the surface of the gallium nitride-based compound semiconductor substrate can be reduced by using abrasive grains having very small grain diameters and polishing the surface of the gallium nitride-based compound semiconductor substrate while gradually lowering polishing speed. Further, the crystallinity of the surface of the gallium nitride-based compound semiconductor substrate can be improved while maintaining excellent surface flatness after polishing by removing a surface damage layer by etching the surface of the gallium nitride-based compound semiconductor substrate subjected to polishing with a low etching rate using RIE.