| 摘要 |
A nitride semiconductor substrate suitable for a normally-off type high breakdown-voltage device and a method of manufacturing the substrate are provided allowing both a higher threshold voltage and improvement in current collapse. In a nitride semiconductor substrate 10 having a substrate 1, a buffer layer 2 formed on one principal plane of the substrate 1, an intermediate layer 3 formed on the buffer layer 2, an electron transport layer 4 formed on the intermediate layer 3, and an electron supply layer 5 formed on the electron transport layer 4, the intermediate layer 3 has a thickness of 200 nm to 1500 nm and a carbon concentration of 5�1016 atoms/cm3 to 1�1018 atoms/cm3 and is of AlxGa1-xN (0.05≰x≰0.24), and the electron transport layer 4 has a thickness of 5 nm to 200 nm and is of AlyGa1-yN (0≰y≰0.04). |
