Abstract: According to one embodiment, a wafer includes a substrate including SiC, and a first layer including SiC. The first layer is in contact with the substrate. The first layer includes Cr. The substrate does not include Cr. Or a concentration of Cr in the substrate is lower than a concentration of Cr in the first layer. A substrate length of the substrate in a second direction crossing a first direction from the substrate to the first layer is longer than a first layer length of the first layer in the second direction.

Abstract: According to one embodiment, a semiconductor device includes a base, a first silicon carbide region, and a second silicon carbide region. The first silicon carbide region includes at least one selected from the group consisting of nitrogen, phosphorus and arsenic. The second silicon carbide region includes at least one selected from the group consisting of boron, aluminum and gallium. The first silicon carbide region is provided between the base and the second silicon carbide region. At least a part of the first silicon carbide region includes fluorine.

Abstract: A semiconductor device of embodiments includes: a silicon carbide layer having a first face and a second face parallel to a first direction and a second direction perpendicular to the first direction; a first trench, a second trench, and a third trench extending in the first direction; a first region of n-type disposed in the silicon carbide layer; a second region of p-type disposed in the silicon carbide layer, disposed between the first region of n-type and the first face, and disposed between the first trench and the second trench; a sixth region of p-type disposed in the silicon carbide layer and disposed on a bottom surface of the first trench; a seventh region of p-type disposed in the silicon carbide layer and disposed on a bottom surface of the second trench; an eighth region of p-type disposed in the silicon carbide layer and disposed on a bottom surface of the third trench; a ninth region of p-type disposed in the silicon carbide layer and in contact with the sixth region and the second region; and

Abstract: A semiconductor device of embodiments includes: a silicon carbide layer having a first face parallel to a first direction and a second direction crossing the first direction and a second face facing the first face; a first trench on a side of the first face extending in the first direction; a second trench extending in the first direction; a third trench extending in the second direction and continuous with the first trench and the second trench; a fourth trench extending in the first direction, disposed between the first trench and the second trench, and spaced from the third trench in the first direction; a gate electrode in the first to fourth trench; a gate insulating layer; a first conductive layer crossing the third trench and connected to the gate electrode; a first electrode disposed on the first face; and a second electrode disposed on the second face.

Abstract: A semiconductor device of embodiments includes: a silicon carbide layer having a first face and a second face; a trench in the silicon carbide layer extending in a first direction; a gate electrode disposed in the trench; a first silicon carbide region of n-type; a second silicon carbide region of p-type between the first silicon carbide region and the first face being shallower than the trench; a third silicon carbide region of n-type disposed between the second silicon carbide region and the first face; a fourth silicon carbide region of n-type disposed between the third silicon carbide region and the first face, a width of the fourth silicon carbide region in a second direction perpendicular to the first direction being smaller than a width of the third silicon carbide region in the second direction; and a first electrode in contact with the fourth silicon carbide region.

Abstract: A semiconductor device according to an embodiment includes: a silicon carbide layer having a first plane parallel to a first direction and a second direction orthogonal to the first direction, and a second plane facing the first plane, the silicon carbide layer including a first trench and a second trench extending in the first direction; a gate electrode in the first trench and the second trench; a gate insulating layer; a gate wiring extending in the second direction, intersecting with the first trench and the second trench, connected to the gate electrode; a first electrode; a second electrode; and an interlayer insulating layer provided between the gate electrode and the first electrode. Neither the gate electrode nor the gate wiring is present between an end of the first trench in the first direction and the interlayer insulating layer.

Abstract: According to one embodiment, a semiconductor device includes a supporter including a first surface, first, second, and third conductive parts, a semiconductor region, and an insulating part. A first direction from the first toward second conductive part is along the first surface. The semiconductor region includes first, second, and third partial regions. A second direction from the first toward second partial region is along the first surface and crosses the first direction. The third partial region is between the first partial region and the second conductive part in the first direction. The third partial region includes a counter surface facing the second conductive part. A direction from the counter surface toward the third conductive part is along the second direction. The insulating part includes an insulating region. At least a portion of the insulating region is between the counter surface and the third conductive part.

Abstract: According to one embodiment, a wafer includes a base body including a first surface, and a crystal layer provided on the first surface. The crystal layer includes first stacking faults and one or second stacking faults. One of the first stacking faults includes a first long side, a first short side, and a first hypotenuse. A position of the first long side in a first direction from the base body to the crystal layer is between the base body in the first direction and a first corner portion in the first direction. One of the one or the plurality of second stacking faults includes a second long side, a second short side, and a second hypotenuse. A position of a second corner portion in the first direction is between the base body in the first direction and the second long side in the first direction.

Abstract: A semiconductor device manufacturing method of embodiments includes: forming a silicon oxide film on a surface of a silicon carbide layer; performing a first heat treatment in an atmosphere containing nitrogen gas at a temperature equal to or more than 1200° C. and equal to or less than 1600° C.; and performing a second heat treatment in an atmosphere containing nitrogen oxide gas at a temperature equal to or more than 750° C. and equal to or less than 1050° C.

Abstract: A semiconductor device of embodiments includes: a silicon carbide layer including a trench, a n-type first SiC region, a p-type second SiC region on the first SiC region, a n-type third SiC region on the second SiC region, a fourth SiC region of p-type between the first trench and the first SiC region, and a fifth SiC region electrically connecting the second SiC region and the fourth SiC region; and a gate electrode in the trench. The first trench has a first region extending in a first direction, a second region continuous with the first region, and a third region continuous with the second region and extending in the first direction. The second width of the second region in the second direction is larger than the first width of the first region in the second direction. The fifth SiC region is disposed in the second direction of the second region.

Abstract: According to one embodiment, a method for manufacturing a semiconductor device is disclosed. The method can include preparing a structure body, the structure body including a silicon carbide member and a first film stacked with the silicon carbide member. The first film includes silicon and oxygen. The method can include performing a first treatment of heat-treating the structure body in a first atmosphere including hydrogen. The method can include, after the first treatment, performing a second treatment of heat-treating the structure body in a second atmosphere including nitrogen and oxygen. An oxygen concentration in the second atmosphere is not less than 5 ppm and not more than 1000 ppm.

Abstract: According to one embodiment, a wafer includes a substrate and a crystal layer. The substrate includes a plurality of SiC regions including SiC and an inter-SiC region including Si provided between the SiC regions. The crystal layer includes a first layer, and a first intermediate layer provided between the substrate and the first layer in a first direction. The first layer includes SiC and nitrogen. The first intermediate layer includes SiC and nitrogen. A second concentration of nitrogen in the first intermediate layer is higher than a first concentration of nitrogen in the first layer.

Abstract: A semiconductor device of an embodiment includes: a first trench in a silicon carbide layer and extending in a first direction; a second trench and a third trench located in a second direction orthogonal to the first direction with respect to the first trench and adjacent to each other in the first direction, n type first silicon carbide region, p type second silicon carbide region on the first silicon carbide region, n type third silicon carbide region on the second silicon carbide region, p type fourth silicon carbide region between the first silicon carbide region and the second trench, and p type fifth silicon carbide region located between the first silicon carbide region and the third trench; a gate electrode in the first trench; a first electrode; and a second electrode. A part of the first silicon carbide region is located between the second trench and the third trench.

Abstract: A semiconductor device of an embodiment includes a first trench extending in a first direction in a silicon carbide layer; a second trench and a third trench adjacent to each other in the first direction; a first silicon carbide region of n type; a second silicon carbide region of p type on the first silicon carbide region; a third silicon carbide region of n type on the second silicon carbide region; a fourth silicon carbide region of p type between the first silicon carbide region and the second trench; a fifth silicon carbide region of p type between the first silicon carbide region and the third trench; a gate electrode in the first trench; a first electrode, part of which is in the second trench, the first electrode contacting the first silicon carbide region between the fourth silicon carbide region and the fifth silicon carbide region; and a second electrode.

Abstract: According to one embodiment, a semiconductor device includes first, and second conductive members, first, second, and third semiconductor regions, and an insulating part. A direction from the first conductive member toward the second conductive member is along a first direction. The first semiconductor region includes first and second partial regions. A second direction from the first partial region toward the second partial region crosses the first direction. The first conductive member is between the first partial region and the second conductive member. A direction from the second partial region toward the second semiconductor region is along the first direction. A direction from the second conductive member toward the second semiconductor region is along the second direction. The third semiconductor region is between the second partial region and the second semiconductor region. The insulating part includes a first insulating region, a second insulating region, and a third insulating region.

Abstract: A semiconductor device of an embodiment includes: a first trench located in a silicon carbide layer extending in a first direction; a second trench and a third trench adjacent to each other in the first direction; n type first silicon carbide region; p type second silicon carbide region on the first silicon carbide region; n type third silicon carbide region on the second silicon carbide region; p type fourth silicon carbide region between the first silicon carbide region and the second trench; p type fifth silicon carbide region between the first silicon carbide region and the third trench; p type sixth silicon carbide region shallower than the second trench between the second trench and the third trench and having a p type impurity concentration higher than that of the second silicon carbide region; a gate electrode in the first trench; a first electrode, and a second electrode.

Abstract: A semiconductor device of an embodiment includes an element region and a termination region surrounding the element region. The element region includes a gate trench, a first silicon carbide region of n-type, a second silicon carbide region of p-type on the first silicon carbide region, a third silicon carbide region of n-type on the second silicon carbide region, and a fourth silicon carbide region of p-type sandwiches the first silicon carbide region and the second silicon carbide region with the gate trench, the fourth silicon carbide region being deeper than the gate trench. The termination region includes a first trench surrounding the element region, and a fifth silicon carbide region of p-type between the first trench and the first silicon carbide region, the fifth silicon carbide region same or shallower than the fourth silicon carbide region. The semiconductor device includes a gate electrode, a first electrode, and a second electrode.

Abstract: A semiconductor device according to an embodiment includes: a silicon carbide layer having a first plane parallel to a first direction and a second direction orthogonal to the first direction, and a second plane facing the first plane, the silicon carbide layer including a first trench and a second trench extending in the first direction; a gate electrode in the first trench and the second trench; a gate insulating layer; a gate wiring extending in the second direction, intersecting with the first trench and the second trench, connected to the gate electrode; a first electrode; a second electrode; and an interlayer insulating layer provided between the gate electrode and the first electrode. Neither the gate electrode nor the gate wiring is present between an end of the first trench in the first direction and the interlayer insulating layer.

Abstract: According to one embodiment, a semiconductor device includes first, second and third conductive parts, a first semiconductor region, and a first insulating part. A direction from the first conductive part toward the second conductive part is along a first direction. The first semiconductor region includes first, second, and third partial regions. A second direction from the first partial region toward the second partial region crosses the first direction. The third partial region is between the first partial region and the second conductive part in the first direction. The third partial region includes an opposing surface facing the second conductive part. A direction from the opposing surface toward the third conductive part is along the second direction. The first insulating part includes a first insulating region. At least a portion of the first insulating region is between the opposing surface and the third conductive part.

Abstract: An embodiment of a semiconductor device including a silicon carbide layer having a first and a second planes; a first silicon carbide region of first conductivity type in the silicon carbide layer; a second silicon carbide region of second conductivity type in the silicon carbide layer between the first silicon carbide region and the first plane; a third silicon carbide region of the first conductivity type in the silicon carbide layer located between the second silicon carbide region and the first plane; a first electrode located on a side of the first plane; a second electrode located on a side of the second plane; a gate electrode; an aluminum nitride layer containing an aluminum nitride crystal between the second silicon carbide region and the gate electrode; and an insulating layer between the aluminum nitride layer and the gate electrode and having a wider band gap than the aluminum nitride layer.