| 摘要 |
Provided is a semiconductor substrate in which characteristics such as the voltage resistance required for a Group III nitride semiconductor layer are satisfied when forming the Group III nitride semiconductor layer using an epitaxial growth method on a Si substrate, and in which low warpage is obtained while securing in-plane uniformity of physical properties such as sheet resistance. A semiconductor substrate is provided in which: a nitride crystal layer on a silicon substrate has a reaction-suppressing layer for suppressing a reaction between silicon atoms and the III-type atoms, a stress-generating layer for generating compression stress, and an active layer in which an electron element is formed; the reaction-suppressing layer, the stress-generating layer, and the active layer are arranged in the stated order from the silicon-substrate side; and the stress-generating layer has a first crystal layer in which the lattice constant in a bulk crystal state is a1, and a second crystal layer, positioned adjacent to the active-layer side of the first crystal layer, in which the lattice constant in a bulk crystal state is a2 (a1 < a2). |
