Abstract: In forming an n+-type source region in a surface region of a p-type base layer by ion implantation, ion implantation of arsenic and ion implantation of nitrogen are sequentially performed. The ion implantation of nitrogen is performed by acceleration energy higher than that of the ion implantation of arsenic. The n+-type source region has an arsenic concentration profile and a nitrogen concentration profile formed to overlap each other at a different depth from the front surface of the base substrate. A peak of the nitrogen concentration profile is positioned deeper than a peak of the arsenic concentration profile from the front surface of the base substrate. The overall impurity concentration distribution of the n+-type source region is a concentration profile that is formed by summing the arsenic concentration profile and the nitrogen concentration profile with each other and whose diffusion depth is large.

Abstract: A method of manufacturing a silicon carbide semiconductor device includes forming a first silicon carbide layer of a first conductivity type on a front surface of a silicon carbide semiconductor substrate. A thermal oxidation film is formed on a surface of a base body including the first silicon carbide layer. The thermal oxidation film is subsequently removed using a solution containing hydrofluoric acid. The base body is washed with a mixture of ammonia water and a hydrogen peroxide solution, a mixture of hydrochloric acid and a hydrogen peroxide solution, and a dilute hydrofluoric acid. The base body is held at temperature of 700 degrees C. to 1700 degrees C., and an insulating film is deposited on the base body.

Abstract: An insulated-gate semiconductor device includes: an n+-type current spreading layer disposed on an n?-type drift layer; a p-type base region disposed on the current spreading layer; a n+-type main-electrode region arranged in an upper portion of the base region; an insulated-gate electrode structure provided in a trench; and a p+-type gate-bottom protection-region being in contact with a bottom of the trench, including a plurality of openings through which a part of the current spreading layer penetrates, being selectively buried in the current spreading layer, wherein positions of the openings cut on both sides of a central line of the trench are shifted from each other about the central line in a longitudinal direction of the trench in a planar pattern.

Abstract: A semiconductor device includes an N-type silicon carbide substrate, an N-type silicon carbide layer formed on the N-type silicon carbide substrate, a P-type region selectively formed in a surface layer of the N-type silicon carbide layer, an N-type source region formed in the P-type region, a P contact region formed in the P-type region, a gate insulating film formed on a portion of a region from the N-type source region, through the P-type region, to the N-type silicon carbide layer, a gate electrode formed on the gate insulating film, an interlayer insulating film covering the gate electrode, and a first source electrode electrically connected to a surface of the P contact region and the N-type source region. An end of the interlayer insulating film covering the gate electrode has a slope of a predetermined angle.

Abstract: In a termination structure region, a first semiconductor layer of a first conductivity type, with an impurity concentration lower than that of a semiconductor substrate, is provided on the substrate of the first conductivity type. A second semiconductor layer of a second conductivity type is provided on a first side of the first semiconductor layer, opposite to a second side facing the substrate. Trenches penetrate the second semiconductor layer. At the first side in the first semiconductor layer, a first semiconductor region of the second conductivity type, with an impurity concentration higher than that of the second semiconductor layer, is provided at a side closer to an active region, contacting the second semiconductor layer. A second semiconductor region of the first conductivity type is provided in the second semiconductor layer, outside and adjacent to one of the trenches that is disposed at a farthest position from the active region.

Abstract: A semiconductor device includes an n-type silicon carbide epitaxial layer on a front surface of an n+-type silicon carbide substrate. A first p+-type base region is provided in the n-type silicon carbide epitaxial layer and a breakdown voltage structure region is provided in an outer periphery of an active region through which a main current flows. A distance between the first p+-type base region and a front surface of the n+-type silicon carbide substrate is smaller than a distance between the breakdown voltage structure region and the front surface of the n+-type silicon carbide substrate.

Abstract: On a surface of an n-type silicon carbide epitaxial layer on an n+-type silicon carbide substrate, first and second p+-type base regions are formed in the n-type silicon carbide epitaxial layer, an n-type region is formed in the n-type silicon carbide epitaxial layer, a p-type base layer is formed on the n-type region, an n+-type source region and a p++-type contact region are formed in the p-type base layer, and a trench is formed to a position shallower than the second p+-type base region and penetrates the p-type base layer. A first sidewall angle of the trench at a position of the p-type base layer is 80° to 90° with respect to a main surface. A difference of the first sidewall angle and a second sidewall angle of the trench at a position deeper than a boundary of the p-type base layer and the n-type region is 1° to 25°.

Abstract: A semiconductor device includes an n+-type source region having an impurity concentration higher than that of an n-type source region, formed in a surface layer of a p-type SiC layer and a p-type base region, farther on an outer side than the n-type source region, and contacting the n-type source region; an n-type region and an n+-type region having an impurity concentration higher than that of the n?-type SiC layer, formed in a portion of the n?-type SiC layer between p-type base regions and p-type SiC layers; and a second n-type region under the p-type base region and of a size smaller than that of the p-type base region, whereby low on-resistance and precision of the threshold voltage Vth are enhanced, increasing quality and enabling improved resistance to dielectric breakdown of the gate insulating film and resistance to breakdown.

Abstract: A silicon carbide semiconductor device includes a silicon carbide semiconductor substrate of a first conductivity type, a first silicon carbide layer of the first conductivity type, and an insulating film. In the silicon carbide semiconductor device, no fluorine or chlorine is detectable in the insulating film, at a boundary layer of the insulating film and the first silicon carbide layer, or at the surface of first silicon carbide layer where the insulating film is provided.

Abstract: A silicon carbide semiconductor device, including a silicon carbide semiconductor structure, an insulated gate structure including a gate insulating film contacting the silicon carbide semiconductor structure and a gate electrode formed on the gate insulating film, an interlayer insulating film covering the insulated gate structure, a metal layer provided on the interlayer insulating film for absorbing or blocking hydrogen, and a main electrode provided on the metal layer and electrically connected to the silicon carbide semiconductor structure.

Abstract: A semiconductor device of an embodiment includes a p+-type region selectively disposed in a surface of an n-type silicon carbide epitaxial layer disposed on an n+-type silicon carbide substrate, an element structure that includes a source electrode and a p+-type region that form a metal-semiconductor junction on the n-type silicon carbide epitaxial layer, a p?-type region and another p?-type region that surround the periphery of the element structure, and an n+-type channel stopper region that surrounds the periphery of the p?-type regions so that the n-type silicon carbide epitaxial layer is therebetween. The n+-type channel stopper region has a second n+-type channel stopper region whose impurity concentration is high, and a first n+-type channel stopper region that encompasses the second n+-type channel stopper region and whose impurity concentration is lower than that of the second n+-type channel stopper region.

Abstract: In a semiconductor device having a first p+-type base region, a second p+-type base region, a high-concentration n-type region selectively formed in an n-type silicon carbide epitaxial layer on an n+-type silicon carbide substrate; a p-type base layer formed on the n-type silicon carbide epitaxial layer; an n+-type source region and a p++-type contact region selectively formed in a surface layer of the p-type base layer; and a trench formed penetrating the p-type base layer and shallower than the second p+-type base region, in at least a part of the first p+-type base region, a region is shallower than the second p+-type base region as viewed from an element front surface side.

Abstract: A silicon carbide semiconductor element includes n-type silicon carbide epitaxial layers formed on an n+-type silicon carbide semiconductor substrate, plural p base layers selectively formed in surfaces of the silicon carbide epitaxial layers, a p-type silicon carbide epitaxial layer formed in the silicon carbide epitaxial layer, and a trench penetrating at least the silicon carbide epitaxial layer. The silicon carbide semiconductor element also includes, in a portion of the silicon carbide epitaxial layer, a mesa portion exposing the p base layer. The silicon carbide semiconductor element further includes, between consecutive mesa side faces of the mesa portion, a flat portion substantially parallel to the silicon carbide substrate. The remaining thickness of the exposed p base layer is larger than 0.5 ?m and smaller than 1.0 ?m.

Abstract: In forming an n+-type source region in a surface region of a p-type base layer by ion implantation, ion implantation of arsenic and ion implantation of nitrogen are sequentially performed. The ion implantation of nitrogen is performed by acceleration energy higher than that of the ion implantation of arsenic. The n+-type source region has an arsenic concentration profile and a nitrogen concentration profile formed to overlap each other at a different depth from the front surface of the base substrate. A peak of the nitrogen concentration profile is positioned deeper than a peak of the arsenic concentration profile from the front surface of the base substrate. The overall impurity concentration distribution of the n+-type source region is a concentration profile that is formed by summing the arsenic concentration profile and the nitrogen concentration profile with each other and whose diffusion depth is large.

Abstract: A silicon carbide semiconductor device includes plural p-type silicon carbide epitaxial layers provided on an n+-type silicon carbide substrate. In some of the p-type silicon carbide epitaxial layers, an n+ source region is provided in at least a region of an upper portion. The n+ source region contains arsenic.

Abstract: A semiconductor device including a semiconductor substrate of a first conductivity type, a plurality of base regions of a second conductivity type formed on a first principal surface of the semiconductor substrate via a semiconductor layer of the first conductivity type, and a plurality of source regions of the first conductivity type formed in the base regions. Each base region, in a top-down view from an angle perpendicular to the first principle surface, is of a polygonal shape. Each adjacent two of the base regions in the top-down view have two sides, one from each of the two base regions, that face each other across a portion of the semiconductor layer, the source region being formed at only one of the two sides.

Abstract: A semiconductor device includes a silicon carbide semiconductor substrate, a first silicon carbide layer of a first conductivity type, a first semiconductor region of a second conductivity type, a second semiconductor region of the first conductivity type, a third semiconductor region of the second conductivity type, a gate insulating film, a gate electrode, an interlayer insulating film, a source electrode, and a drain electrode. The third semiconductor region is thicker than the second semiconductor region and a width of a side of the third semiconductor region facing the first semiconductor region is narrower than a width of a side thereof facing the source electrode.

Abstract: A MOS gate is provided on a front surface side of a silicon carbide substrate. The silicon carbide substrate includes silicon carbide layers sequentially formed on an n+-type starting substrate by epitaxial growth. Of the silicon carbide layers, a p+-type silicon carbide layer is a p+-type high-concentration base region and is separated into plural regions by a trench. A p-type silicon carbide layer among the silicon carbide layers covers the p+-type silicon carbide layer and is embedded in the trench. A p-type silicon carbide layer among the silicon carbide layers is a p-type base region. From a substrate front surface, a gate trench penetrates the p-type base region in the trench and the n+-type source region to reach an n?-type drift region. Between the p+-type high-concentration base region and a gate insulating film at a sidewall of the gate trench, the p-type base region is embedded in the trench.

Abstract: A semiconductor device has an active region through which current flows and an edge termination structure region arranged outside the active region. The semiconductor device includes a low-concentration semiconductor layer of a first conductivity type, and formed in the edge termination structure region, on a front surface of a semiconductor substrate. The semiconductor device includes a second semiconductor layer of a second conductivity type, in contact with one of a semiconductor layer of the second conductivity type in the active region and a semiconductor layer of the second conductivity type in contact with a source electrode. The second semiconductor layer has an impurity concentration that is lower than that of the semiconductor layer, and the second semiconductor layer is not in contact with a surface of the semiconductor substrate.

Abstract: A silicon carbide semiconductor device, including a silicon carbide semiconductor structure, an insulated gate structure including a gate insulating film contacting the silicon carbide semiconductor structure and a gate electrode formed on the gate insulating film, an interlayer insulating film covering the insulated gate structure, a metal layer provided on the interlayer insulating film for absorbing or blocking hydrogen, and a main electrode provided on the metal layer and electrically connected to the silicon carbide semiconductor structure.