| 摘要 |
PROBLEM TO BE SOLVED: To remove a nitride layer from a laminated semiconductor wafer without influencing crystallinity of a substrate and an irregular shape of a substrate surface, by preventing even a physical change such as warpage and deformation caused by heat.SOLUTION: A recycled substrate manufacturing method of recycling a laminated semiconductor substrate by removing a buffer layer 3 of an AlN layer determined as defective from the laminated semiconductor substrate in which the buffer layer 3 of the AlN layer determined as defective is formed on a sapphire substrate 2, and newly forming a buffer layer 3 of an AlN layer comprises: a cleaning process of performing a cleaning treatment by a hydrogen peroxide solution on the laminated semiconductor substrate; and a second cleaning process of performing a cleaning treatment by a compound liquid of sulfuric acid and the hydrogen peroxide solution on the laminated semiconductor substrate (laminated semiconductor wafer) after the first cleaning process. |
