| 摘要 |
PROBLEM TO BE SOLVED: To provide a group III nitride composite substrate which can manufacture a group III nitride semiconductor device at high yield, and has low costs, a large diameter, a thick film thickness, and a small temperature variation on a main plane when a group III nitride semiconductor layer grows, a method for manufacturing the same, a lamination group III nitride composite substrate, a group III nitride semiconductor device, and a method for manufacturing the same.SOLUTION: A group III nitride composite substrate 1 is a group III nitride composite substrate 1 in which a diameter where a support substrate 11 is stuck to a group III nitride film 13 having a thickness of≥10μm and≤250μm, is equal to or more than 75 mm. An average mof root-mean-square roughness of a main plane 11n at the support substrate 11 side, is≥0.3 nm and≤20nm, and a ratio s/mof standard deviation sof the root-mean-square roughness to the average mof root-mean-square roughness of the main plane 11n at the support substrate 11 side, is≥0.005 and≤0.4. |
