GROUP III NITRIDE EPITAXIAL SUBSTRATE AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a group III nitride epitaxial substrate and a manufacturing method of the same, which reduces warpage after forming a main laminate and improves a vertical breakdown voltage.SOLUTION: A group III nitride epitaxial substrate 10 of the present embodiment comprises: an Si substrate 11; an initial layer 14 having contact with the Si substrate 11; and a superlattice laminate 15 which is formed on the initial layer 14 and in which first layers 15A1 (15B1) composed of AlGaN(0.5<α≤1) and second layers 15A2 (15B2) composed of AlGaN(0<&bgr;≤0.5) are alternately laminated. An Al composition &bgr; of the second layer gradually increases with distance from the Si substrate.