| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon carbide semiconductor device which ensures reduction of gate threshold voltage, improvement of gate-source and gate-drain insulation voltage, reduction of a leakage current when the device is off, further reduction of on resistance, and improved reliability of a gate oxide film. SOLUTION: A semiconductor substrate 4 includes an n<+> type substrate 1, an n<-> type silicon carbide semiconductor layer 2, and a p type silicon carbide semiconductor layer 3. Orientation of a principal surface is substantially (0001-) carbon plane and comprises hexagonal single crystal silicon carbide. An n<+> type source region 5 is formed on a surface layer part of the semiconductor layer 3, and a trench 7 reaches the semiconductor layer 2 after passage through the area 5 and the semiconductor layer 3 from the principal surface, and is extended substantially in the direction [112-0]. An n type silicon carbide semiconductor thin film layer 8 is extended to the area 5 on the side surface of the trench 7 and on the surface of the semiconductor layer 3 and the semiconductor layer 2. A gate electrode layer 10 is formed inside a gate insulating film 9, a source elecrtode layer 10 is formed on the surface of the semiconductor region 5, and a drain electrode layer 13 is formed on the surface of the n<+> type substrate 1. |
