| 摘要 |
PROBLEM TO BE SOLVED: To provide a group III nitride semiconductor substrate having a flat face with dangling bond density of more than 14.0 nm.SOLUTION: A 2 μm (0001) face GaN is grown on a sapphire substrate with a diameter of 2 inches and thickness of 430 μm by an MOCVD method, so as to form a template substrate, and a GaN single crystal with thickness of 5 mm is grown by an HVPE device. A GaN substrate from which a (11-2-2) face is cut out by slicing is wrapped, and processing damage is removed. Thereafter, the substrate is etched with a KOH solution, so as to remove wrapping damage. Then, the substrate is wrapped with a (11-22) face as a top surface, and processing damage due to slicing is removed. Thereafter, the substrate is polished by slurry containing colloidal silica. After the colloidal silica is removed by a cleaning agent containing NHF, the cleaning agent is removed by pure water, and moisture is dried by a spin dryer, so as to obtain the GaN substrate with the (11-22) face as a principal surface. |
