| abstract |
Provided is a method for manufacturing a group III-nitride semiconductor substrate, the method comprising: a sapphire substrate preparation step S10 of preparing a sapphire substrate that has, as a principal surface, a {10-10} plane or a surface tilted a predetermined angle in a predetermined direction from the {10-10} plane; a heat treatment step S20 of heat treating the sapphire substrate while performing or not performing a nitriding treatment; a buffer layer forming step S30 of forming a buffer layer on the principal surface of the sapphire substrate after the heat treatment; and a growing step S40 of forming, on the buffer layer, a group III-nitride semiconductor layer having a growth surface oriented in a predetermined plane direction, wherein at least one among the plane direction of the principal surface of the sapphire substrate, whether or not to perform the nitriding treatment during the heat treatment, and the growth temperature in the buffer layer forming step is adjusted so that the growth surface of the group III-nitride semiconductor layer is oriented in the predetermined plane direction. |