Abstract: A semiconductor device according to an embodiment includes: a silicon carbide layer; a silicon oxide layer; and a region disposed between the silicon carbide layer and the silicon oxide layer and having a nitrogen concentration equal to or more than 1×1021 cm?3. A nitrogen concentration distribution in the silicon carbide layer, the silicon oxide layer, and the region have a peak in the region, a nitrogen concentration at a first position 1 nm away from the peak to the side of the silicon oxide layer is equal to or less than 1×1018 cm?3 and a carbon concentration at the first position is equal to or less than 1×1018 cm3, and a nitrogen concentration at a second position 1 nm away from the peak to the side of the silicon carbide layer is equal to or less than 1×1018 cm?3.

Abstract: A semiconductor device of an embodiment includes: a nitride semiconductor layer including a first GaN region of n-type, a second GaN region of n-type on the first GaN region, a third GaN region of p-type on the first GaN region, a fourth GaN region of p-type sandwiching the second GaN region with the third GaN region, a fifth GaN region of p-type on the third GaN region, a sixth GaN region of p-type sandwiching the second GaN region with the fifth GaN region, a seventh GaN region of n-type on the fifth GaN region, an eighth GaN region of n-type on the sixth GaN region, a trench between the seventh GaN region and the eighth GaN region, the trench having an inclination angle of less than 90 degrees; a gate insulating layer including an aluminum nitride film in the trench; a gate electrode; a first electrode; and a second electrode.

Abstract: A semiconductor device of an embodiment includes: a silicon carbide layer including a first silicon carbide region of n-type containing one metal element selected from a group consisting of nickel (Ni), palladium (Pd), platinum (Pt), and chromium (Cr) and a second silicon carbide region of p-type containing the metal element; and a metal layer electrically connected to the first silicon carbide region and the second silicon carbide region. Among the metal elements contained in the first silicon carbide region, a proportion of the metal element positioned at a carbon site is higher than a proportion of the metal element positioned at an interstitial position. Among the metal elements contained in the second silicon carbide region, a proportion of the metal element positioned at an interstitial position is higher than a proportion of the metal element positioned at a carbon site.

Abstract: A semiconductor device according to an embodiment includes: a silicon carbide layer; a metal layer; and a conductive layer positioned between the silicon carbide layer and the metal layer, the conductive layer containing a silicide of one metal element (M) selected from the group consisting of nickel (Ni), palladium (Pd), and platinum (Pt), and the conductive layer having a carbon concentration of 1×1017 cm?3 or less.

Abstract: A semiconductor device according to an embodiment includes a first electrode; a second electrode; a gate electrode; an n-type first silicon carbide region positioned between the first electrode and the second electrode and between the gate electrode and the second electrode; a p-type second silicon carbide region positioned between the first electrode and the first silicon carbide region; a third silicon carbide region of metal containing at least one element selected from the group consisting of nickel (Ni), palladium (Pd), and platinum (Pt), positioned between the first electrode and the second silicon carbide region and spaced apart from the first silicon carbide region; and a gate insulating layer positioned between the gate electrode and the second silicon carbide region.

Abstract: A semiconductor device according to an embodiment includes a nitride semiconductor layer, an insulating layer provided on the nitride semiconductor layer, a first region provided in the nitride semiconductor layer, and a second region which is provided between the first region in the nitride semiconductor layer and the insulating layer, has a higher electric resistivity than the first region, and includes carbon (C).

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: According to one embodiment, a semiconductor device includes a first electrode, a second electrode, a third electrode, a semiconductor member, and a first crystal member. A direction from the first electrode toward the second electrode is aligned with a first direction. A position in the first direction of the third electrode is between positions in the first direction of the first electrode and the second electrode. The semiconductor member includes at least one selected from the group consisting of silicon carbide, silicon, carbon, and germanium. The semiconductor member includes a first region, and first and second partial regions. The first region is between the first and second electrodes in the first direction. A second direction from the first region toward the third electrode crosses the first direction. The first crystal member is provided between the first and third electrodes in the second direction.

Abstract: A diamond substrate according to an embodiment includes a diamond layer including at least one first element selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi), the number of threefold coordinated atoms of the at least one first element in the diamond layer being larger than the number of fourfold coordinated atoms of the at least one first element in the diamond layer, a surface of the diamond layer having an off angle of 10 degrees or less with respect to a (111) face.

Abstract: A semiconductor device includes a semiconductor layer having first and second planes; a first semiconductor region of a first conductivity type; second and third semiconductor regions of a second conductivity type between the first semiconductor region and the first plane; a fourth semiconductor region of a first conductivity type between the second semiconductor region and the first plane; a fifth semiconductor region of a first conductivity type between the third semiconductor region and the first plane; first and second trenches between the fourth and fifth semiconductor regions and over from the second to third semiconductor region; a sixth semiconductor region between the second and third semiconductor regions and between the first and second trenches; a seventh semiconductor region of a second conductivity type between the first trench and the first semiconductor region and contacting the second and third semiconductor regions; a first and second gate electrode in the trenches.

Abstract: According to an embodiment of the invention, a semiconductor device includes a base body that includes silicon carbide, a first semiconductor member that includes silicon carbide and is of a first conductivity type, and a second semiconductor member that includes silicon carbide and is of a second conductivity type. A first direction from the base body toward the first semiconductor member is along a [0001] direction of the base body. The second semiconductor member includes a first region, a second region, and a third region. The first semiconductor member includes a fourth region. A second direction from the first region toward the second region is along a [1-100] direction of the base body. The fourth region is between the first region and the second region in the second direction. A third direction from the fourth region toward the third region is along a [11-20] direction of the base body.

Abstract: A method of manufacturing semiconductor device of an embodiment includes performing a first ion implantation implanting at least one element selected from a group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), silicon (Si), germanium (Ge), and tin (Sn) into a nitride semiconductor layer; performing a second ion implantation implanting nitrogen (N) into the nitride semiconductor layer; performing a third ion implantation implanting hydrogen (H) into the nitride semiconductor layer; forming a covering layer on a surface of the nitride semiconductor layer after the first ion implantation, the second ion implantation, and the third ion implantation; performing a first heat treatment after forming the covering layer; removing the covering layer after the first heat treatment; and performing a second heat treatment after removing the covering layer.

Abstract: According to one embodiment, a method for manufacturing a substrate is disclosed. The method can include preparing a structure body. The structure body includes a first semiconductor member and a second semiconductor member. The first semiconductor member includes silicon carbide including a first element. The second semiconductor member includes silicon carbide including a second element. The first element includes at least one selected from a first group consisting of N, P, and As. The second element includes at least one selected from a second group consisting of B, Al, and Ga. The method can include forming a hole that extends through the second semiconductor member and reaches the first semiconductor member. In addition, the method can include forming a third semiconductor member in the hole. The third semiconductor member includes silicon carbide including a third element. The third element includes at least one selected from the first group.

Abstract: A method for manufacturing a semiconductor device according to an embodiment includes: forming a first silicon oxide film on a surface of a silicon carbide layer; and performing first heat treatment at 1200° C. or more in an atmosphere including nitrogen gas and carbon dioxide gas.

Abstract: A semiconductor device according to an embodiment includes a gate electrode, a gate insulating layer, and a silicon carbide layer. The silicon carbide layer includes at least one first element selected from the group consisting of S, Se, Te, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. The first distance between a first position and an interface between the gate insulating layer and the silicon carbide layer is equal to or less than 20 nm, and the first position is a position where a concentration of the first element is maximized. The second distance between a second position and the interface is equal to or less than 20 nm, second position is a position where a concentration of the first element is 1/10 of a concentration of the first element at the first position, and the second position is farther from the interface than the first position.

Abstract: A semiconductor device of the embodiment includes: a first region provided in a silicon carbide layer; and a second region provided around the first region in the silicon carbide layer, the second region having a higher concentration of at least one kind of a lifetime killer impurity selected from the group consisting of B (boron), Ti (titanium), V (vanadium), He (helium) and H+ (proton) than a concentration of a lifetime killer impurity in the first region.

Abstract: A semiconductor device includes a p-type SiC layer, a gate electrode, and a gate insulating layer between the SiC layer and the gate electrode. The gate insulating layer includes first and second layers and first and second regions. The second layer is between the first layer and the gate electrode and has a higher oxygen density than the first layer. The first region is across the first layer and the second layer, and includes at least one first element selected from the group consisting of N (nitrogen), P (phosphorus), As (arsenic), Sb (antimony), and Bi (bismuth) and the first region having a first concentration peak of the at least one first element. The second region is provided in the first layer, includes a second element from Ta (tantalum), Nb (niobium), and V (vanadium) and, the second region having a second concentration peak of the at least one second element.

Abstract: According to one embodiment, a semiconductor device includes first to third electrodes, first and second semiconductor regions, and a first insulating film. The first semiconductor region includes a first partial region, a second partial region, a third partial region between the first and second partial regions, a fourth partial region between the first and third partial regions, and a fifth partial region between the third and second partial regions. The second semiconductor region includes a sixth partial region and a seventh partial region. The third electrode overlaps the sixth and seventh partial regions. The first insulating film includes a portion provided between the third electrode and the third partial region, between the third electrode and the fourth partial region, between the third electrode and the fifth partial region, between the third electrode and the sixth partial region, and between the third electrode and the seventh partial region.

Abstract: According to one embodiment, a semiconductor device includes a first layer, a first electrode, and a first nitride region. The first layer includes a first material and a first partial region. The first material includes at least one selected from the group consisting of silicon carbide, silicon, carbon, and germanium. The first partial region is of a first conductivity type. The first conductivity type is one of an n-type or a p-type. A direction from the first partial region toward the first electrode is aligned with a first direction. The first nitride region includes Alx1Ga1-x1N (0?x1<1), is provided between the first partial region and the first electrode, is of the first conductivity type, and includes a first protrusion protruding in the first direction.

Abstract: A semiconductor device includes a semiconductor layer having first and second planes; a first semiconductor region of a first conductivity type; second and third semiconductor regions of a second conductivity type between the first semiconductor region and the first plane; a fourth semiconductor region of a first conductivity type between the second semiconductor region and the first plane; a fifth semiconductor region of a first conductivity type between the third semiconductor region and the first plane; first and second trenches between the fourth and fifth semiconductor regions and over from the second to third semiconductor region; a sixth semiconductor region between the second and third semiconductor regions and between the first and second trenches; a seventh semiconductor region of a second conductivity type between the first trench and the first semiconductor region and contacting the second and third semiconductor regions; a first and second gate electrode in the trenches.