Abstract: A silicon carbide (SiC) substrate is provided with an off-oriented {0001} surface whose off-axis direction is <11-20>. A trench is formed on the SiC to have a stripe structure extending toward a <11-20> direction. An SiC epitaxial layer is formed on an inside surface of the trench.

Abstract: An insulating film (2) is formed on a semiconductor substrate (1) formed of silicon carbide. A contact hole (3) is formed in the insulating film (2) to expose a part of the upper surface of the semiconductor substrate (1). Then, nickel (Ni) (4′) is formed above the semiconductor substrate (1). Subsequently, the semiconductor substrate (1) is subjected to a heat treatment, whereby the contact portion of nickel (4′) chemically bonds with the semiconductor substrate (1) to become an alloy layer (4) of silicon carbide and nickel. Nickel (4′) on the insulating film (2) is selectively removed by etching liquid for dissolving the nickel.

Abstract: A silicon carbide (SiC) substrate is provided with an off-oriented {0001} surface whose off-axis direction is <11-20>. A trench is formed on the SiC to have a stripe structure extending toward a <11-20> direction. An SiC epitaxial layer is formed on an inside surface of the trench.

Abstract: Disclosed is an EGR valve which is compact in size and can increase an amount of exhaust gas to be recirculated in comparison with that of the prior art without deteriorating mountability of an engine to a vehicle. The EGR valve has a housing with a mounting surface adapted to be mounted to an exhaust gas confluence port on a suction pipe, an gas intake pathway extending through the housing along the mounting surface and having longitudinal ends one of which is opened as gas inlet, gas discharge pathways in the housing for communication with longitudinally spaced portions of the gas intake pathway via openings and opened via gas outlets to the mounting surface, and actuators mounted on the housing for moving valve bodies to selectively open and close the openings.

Abstract: A groove is formed on the surface of a semiconductor substrate composed of silicon carbide and a first thermal oxidation film is formed by executing thermal oxidation on a damaged layer of groove inner walls. Then, the first thermal oxidation film is removed so that the damaged layer can be removed. Since a second thermal oxidation film is formed after the damaged layer is removed, the second thermal oxidation film is uniform. A silicon carbide semiconductor device can be achieved with less side etching because substantially a (0001) carbon face of a cubic system is chosen as the plane orientation of the semiconductor substrate.

Abstract: A manufacturing method for a semiconductor device, which can attain a low ion voltage in a manufacturing method for a semiconductor device involving a process for forming a groove by etching prior to selective oxidation, selectively oxidizing a region including the groove and thereby making a channel part of the groove, is disclosed. A groove part is thermally oxidized by using a silicon nitride film as a mask. A LOCOS oxide film is formed by this thermal oxidation, and concurrently a U-groove is formed on the surface of an n.sup.- -type epitaxial layer eroded by the LOCOS oxide film, and the shape of the U-groove is fixed. A curve part formed during a chemical dry etching process remains as a curve part on the side surface of the U-groove. Then, an n.sup.+ -type source layer is formed by means of thermal diffusion to a junction thickness of 0.5 to 1 .mu.m, and a channel is set up as well.