| 摘要 |
PROBLEM TO BE SOLVED: To provide a low defect nitride semiconductor substrate having good crystallinity and a method for growing a nitride semiconductor on a substrate. SOLUTION: After a first nitride semiconductor is grown on a substrate, protrusions and recesses are formed on the surface of the first nitride semiconductor and the upper surface of the protrusions is covered with a protective film. Subsequently, exposed parts are heat treated except the protrusions and a second nitride semiconductor having a different compositional ratio is grown on the bottom and side faces of the recesses in the first nitride semiconductor. Subsequently, the protective film is removed and a third nitride semiconductor is grown from the upper surface of the protrusions thus obtaining a flat, low defect nitride semiconductor substrate. |
