Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. An average value of carrier concentration in the silicon carbide layer is not less than 1×1015 cm?3 and not more than 5×1016 cm?3. In-plane uniformity of the carrier concentration is not more than 2%. The second main surface has: a groove 80 extending in one direction along the second main surface, a width of the groove in the one direction being twice or more as large as a width thereof in a direction perpendicular to the one direction, and a maximum depth of the groove from the second main surface being not more than 10 nm; and a carrot defect. A value obtained by dividing a number of the carrot defects by a number of the grooves is not more than 1/500.

Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. A first ratio of an absolute value of a difference between a dopant density in a first end region and a dopant density in a central region to an average value of the dopant density in the first end region and the dopant density in the central region is not more than 40%. A second ratio of an absolute value of a difference between a dopant density in a second end region and the dopant density in the central region to an average value of the dopant density in the second end region and the dopant density in the central region is not more than 40%.

Abstract: In forming of a silicon carbide layer, when an X axis indicates a first value representing, in percentage, a value obtained by dividing a flow rate of silane by a flow rate of hydrogen and a Y axis indicates a second value representing a flow rate of ammonia in sccm, the first value and the second value fall within a quadrangular region surrounded by first coordinates, second coordinates, third coordinates, and fourth coordinates in XY plane coordinates. The first coordinates are (0.05, 6.5×10?4). The second coordinates are (0.05, 4.5×10?3). The third coordinates are (0.22, 1.2×10?2). The fourth coordinates are (0.22, 1.3×10?1). After the forming of the silicon carbide layer, an average value of carrier concentration of the silicon carbide layer is more than or equal to 1×1015 cm?3 and less than or equal to 2×1016 cm?3.

Abstract: A silicon carbide epitaxial substrate includes: a silicon carbide single crystal substrate; and an epitaxial layer. The silicon carbide single crystal substrate has a diameter of not less than 100 mm. The epitaxial layer has a thickness of not less than 10 ?m. The epitaxial layer has a carrier concentration of not less than 1×1014 cm?3 and not more than 1×1016 cm?3. A ratio of a standard deviation of the carrier concentration in a plane of the epitaxial layer to an average value of the carrier concentration in the plane is not more than 10%. The epitaxial layer has a main surface. The main surface has an arithmetic mean roughness Sa of not more than 0.3 nm. An area density of pits originated from a threading screw dislocation is not more than 1000 cm?2. Each of the pits has a maximum depth of not less than 8 nm.

Abstract: An epitaxial wafer includes a silicon carbide film having a first main surface. A groove portion is formed in the first main surface. The groove portion extends in one direction along the first main surface. Moreover, a width of the groove portion in the one direction is twice or more as large as a width of the groove portion in a direction perpendicular to the one direction. Moreover, a maximum depth of the groove portion from the first main surface is not more than 10 nm.

Abstract: An epitaxial wafer includes a silicon carbide film having a first main surface. A groove portion is formed in the first main surface. The groove portion extends in one direction along the first main surface. Moreover, a width of the groove portion in the one direction is twice or more as large as a width of the groove portion in a direction perpendicular to the one direction. Moreover, a maximum depth of the groove portion from the first main surface is not more than 10 nm.

Abstract: The silicon carbide layer has a second main surface. The second main surface has a peripheral region within 5 mm from an outer edge thereof, and a central region surrounded by the peripheral region. The silicon carbide layer has a central surface layer. An average value of a carrier concentration in the central surface layer is not less than 1×1014 cm?3 and not more than 5×1016 cm?3. Circumferential uniformity of the carrier concentration is not more than 2%, and in-plane uniformity of the carrier concentration is not more than 10%. An average value of a thickness of a portion of the silicon carbide layer sandwiched between the central region and the silicon carbide single-crystal substrate is not less than 5 ?m. Circumferential uniformity of the thickness is not more than 1%, and in-plane uniformity of the thickness is not more than 4%.

Abstract: An epitaxial wafer includes a silicon carbide film having a first main surface. A groove portion is formed in the first main surface. The groove portion extends in one direction along the first main surface. Moreover, a width of the groove portion in the one direction is twice or more as large as a width of the groove portion in a direction perpendicular to the one direction. Moreover, a maximum depth of the groove portion from the first main surface is not more than 10 nm.

Abstract: Provided are a silicon melt contact member which is markedly improved in liquid repellency to a silicon melt, which can retain the liquid repellency permanently, and which is suitable for production of crystalline silicon; and a process for efficient production of crystalline silicon, particularly, spherical crystalline silicon having high crystallinity, by use of the silicon melt contact member. A silicon melt contact member having a porous sintered body layer present on its surface, preferably the sintered body layer being present on a substrate of a ceramic material such as aluminum nitride, wherein the porous sintered body layer consists essentially of silicon nitride, has a thickness of 10 to 500 ?m, and has, dispersed therein, many pores preferably having an average equivalent circle diameter of 1 to 25 ?m at a pore-occupying area ratio of 30 to 80%, the pores connecting to each other to form communicating holes having a depth of 5 ?m or more.

Abstract: A nanostructure including a nanoporous material having micropores filled with a fragmented thin-film material from the opening-side of each micropore, the nanoporous material being obtained by placing a thin-film material on a surface of a nanoporous material and pressing the thin-film material so that the thin-film material is cut out at the surface edge of each micropore of the nanoporous material and pressed into the micropore. By removing the nanoporous material form the nanoporous material, microparticles constituted from the thin-film material that filled the nanoporous material are obtained. By covering all the wall surfaces of the micropores of the nanoporous material in advance, nanocapsules each constituted from a tubular structure composed of the thin film covering the entire wall surface of the micropore and a cover made of a thin-film material filled in the vicinity of the opening of the micropore can be formed.

Abstract: An object is to produce uniformly sized, nanosized microparticles in a short time in large numbers by a simple procedure. Although a technique of filling micropores of nanoporous material with a metal from the bottoms of the micropores by electrodeposition or by a sol-gel method has been available, there has been no process for covering the openings of the micropores or process for producing nanocapsules. A nanostructure including a nanoporous material having micropores filled with a fragmented thin-film material from the opening-side of each micropore, the nanoporous material being obtained by placing a thin-film material on a surface of a nanoporous material and pressing the thin-film material so that the thin-film material is cut out at the surface edge of each micropore of the nanoporous material and pressed into the micropore. By removing the nanoporous material form the nanoporous material, microparticles constituted from the thin-film material that filled the nanoporous material are obtained.

Abstract: A circuit module comprises a circuit board and a circuit element mounted on the circuit board and producing heat in operation. A heat conduction member, put in contact with the circuit element, for receiving the heat of the circuit element is attached to the circuit board. A metallic heat sink is detachably mounted on the heat conduction member. The heat sink comprises a radiation panel put in contact with the heat conduction member and a fan support portion formed integral with the radiation panel. The fan support portion supports a cooling fan for guiding a cooling air to the radiation panel.