Abstract: A first layer has n type conductivity. A second layer is epitaxially formed on the first layer and having p type conductivity. A third layer is on the second layer and having n type conductivity. ND is defined to represent a concentration of a donor type impurity. NA is defined to represent a concentration of an acceptor type impurity. D1 is defined to represent a location in the first layer away from an interface between the first layer and the second layer in a depth direction. D1 in which 1?ND/NA?50 is satisfied is within 1 ?m therefrom. A gate trench is provided to extend through the third layer and the second layer to reach the first layer. A gate insulating film covers a side wall of the gate trench. A gate electrode is embedded in the gate trench with the gate insulating film interposed therebetween.

Abstract: A silicon carbide semiconductor device includes a silicon carbide substrate. The silicon carbide substrate is composed of an element region provided with a semiconductor element portion and a termination region surrounding the element region as viewed in a plan view. The semiconductor element portion includes a drift region having a first conductivity type. The termination region includes a first electric field relaxing region contacting the element region and having a second conductivity type different from the first conductivity type, and a second electric field relaxing region arranged outside the first electric field relaxing region as viewed in the plan view, having the second conductivity type, and spaced from the first electric field relaxing region. A ratio calculated by dividing a width of the first electric field relaxing region by a thickness of the drift region is not less than 0.5 and not more than 1.83.

Abstract: There are provided a high-quality semiconductor device having stable characteristics and a method for manufacturing such a semiconductor device. The semiconductor device includes a substrate having a main surface, and a silicon carbide layer. The silicon carbide layer is formed on the main surface of the substrate. The silicon carbide layer includes a side surface as an end surface inclined relative to the main surface. The side surface substantially includes one of a {03-3-8} plane and a {01-1-4} plane in a case where the silicon carbide layer is of hexagonal crystal type, and substantially includes a {100} plane in a case where the silicon carbide layer is of cubic crystal type.

Abstract: A wide gap semiconductor device includes a substrate and a Schottky electrode. The substrate formed of a wide gap semiconductor material has a main face, and includes a first-conductivity-type region and a second-conductivity-type region. The Schottky electrode is arranged adjoining the main face of the substrate. At the substrate, there is foamed a trench having a side face continuous with the main face and a bottom continuous with the side face. The Schottky electrode adjoins the first-conductivity-type region at the side face of the trench and the main face, and adjoins the second-conductivity-type region at the bottom of the trench. The side face of the trench is inclined relative to the main face of the substrate.

Abstract: The substrate is made of a compound semiconductor, and has a recess, which opens at one main surface and has side wall surfaces when viewed in a cross section along a thickness direction. The gate insulating film is disposed on and in contact with each of the side wall surfaces. The substrate includes a source region having first conductivity type and disposed to be exposed at the side wall surface; and a body region having second conductivity type and disposed in contact with the source region at a side opposite to the one main surface so as to be exposed at the side wall surface, when viewed from the source region. The recess has a closed shape when viewed in a plan view. The side wall surfaces provide an outwardly projecting shape in every direction when viewed from an arbitrary location in the recess.

Abstract: A first drift layer has a first surface facing a first electrode and electrically connected to a first electrode, and a second surface opposite to the first surface. The first drift layer has an impurity concentration NA. A relaxation region is provided in a portion of the second surface of the first drift layer. The first drift layer and the second drift layer form a drift region in which the relaxation region is buried. The second drift layer has an impurity concentration NB, NB>NA being satisfied. A body region, a source region, and a second electrode are provided on the second drift layer.

Abstract: A first region of a silicon carbide layer constitutes a first surface, and is of a first conductivity type. A second region is provided on the first region, and is of a second conductivity type. A third region is provided on the second region, and is of the first conductivity type. A fourth region is provided in the first region, located away from each of the first surface and the second region, and is of the second conductivity type. A gate insulation film is provided on the second region so as to connect the first region with the third region. A gate electrode is provided on the gate insulation film. A first electrode is provided beneath the first region. A second electrode is provided on the third region.

Abstract: A trench having a side wall and a bottom portion is formed in a silicon carbide substrate. A trench insulating film is formed to cover the bottom portion and the side wall. A silicon film is formed to fill the trench with the trench insulating film being interposed therebetween. The silicon film is etched so as to leave a portion of the silicon film that is disposed on the bottom portion with the trench insulating film being interposed therebetween. The trench insulating film is removed from the side wall. By oxidizing the silicon film, a bottom insulating film is formed. A side wall insulating film is formed on the side wall.

Abstract: The substrate is made of a compound semiconductor and has a plurality of first recesses, each of which opens at one main surface thereof and has a first side wall surface. The gate insulating film is disposed on and in contact with the first side wall surface. The gate electrode is disposed on and in contact with the gate insulating film. The substrate include: a source region having first conductivity type and disposed to face itself with a first recess interposed therebetween, when viewed in a cross section along the thickness direction; and a body region having second conductivity type and disposed to face itself with the first recess interposed therebetween. Portions of the source region facing each other are connected to each other in a region interposed between the first recess and another first recess adjacent to the first recess, when viewed in a plan view.

Abstract: On a p? epitaxial layer, an n-type epitaxial layer and a gate region are formed in this order. A gate electrode is electrically connected to the gate region, and a source electrode and a drain electrode are spaced apart from each other with the gate electrode sandwiched therebetween. A control electrode is used for applying to the p? epitaxial layer a voltage that causes a reverse biased state of the p? epitaxial layer and the n-type epitaxial layer in an OFF operation.

Abstract: A termination configuration of a silicon carbide insulating gate type semiconductor device includes a semiconductor layer of a first conductivity type having a first main face, a gate electrode, and a source interconnection, as well as a circumferential resurf region. The semiconductor layer includes a body region of a second conductivity type, a source region of the first conductivity type, a contact region of the second conductivity type, and a circumferential resurf region of the second conductivity type. A width of a portion of the circumferential resurf region excluding the body region is greater than or equal to ½ the thickness of at least the semiconductor layer. A silicon carbide insulating gate type semiconductor device of high breakdown voltage and high performance can be provided.

Abstract: A silicon carbide substrate includes a first layer of a first conductivity type, a second layer of a second conductivity type provided on the first layer, and a third layer provided on the second layer and doped with an impurity for providing the first conductivity type. The silicon carbide substrate has a trench formed through the third layer and the second layer to reach the first layer. The first layer has a concentration peak of the impurity in a position away from the trench in the first layer. As a result, a silicon carbide semiconductor device having an electric field relaxation structure that can be readily formed is provided.

Abstract: A silicon carbide substrate has a first conductivity type. The silicon carbide substrate has a first surface provided with a first electrode and a second surface provided with first trenches arranged to be spaced from one another. A gate layer covers an inner surface of each of the first trenches. The gate layer has a second conductivity type different from the first conductivity type. A filling portion fills each of the first trenches covered with the gate layer. A second electrode is separated from the gate layer and provided on the second surface of the silicon carbide substrate. A gate electrode is electrically insulated from the silicon carbide substrate and electrically connected to the gate layer. Thereby, a silicon carbide semiconductor device capable of being easily manufactured can be provided.

Abstract: A first drift layer has a first surface facing a first electrode and electrically connected to a first electrode, and a second surface opposite to the first surface. The first drift layer has an impurity concentration NA. A relaxation region is provided in a portion of the second surface of the first drift layer. The first drift layer and the second drift layer form a drift region in which the relaxation region is buried. The second drift layer has an impurity concentration NB, NB>NA being satisfied. A body region, a source region, and a second electrode are provided on the second drift layer.

Abstract: A silicon carbide semiconductor device includes an insulation film, and a silicon carbide layer having a surface covered with the insulation film. The surface includes a first region. The first region has a first plane orientation at least partially. The first plane orientation is any of a (0-33-8) plane, (30-3-8) plane, (-330-8) plane, (03-3-8) plane, (-303-8) plane, and (3-30-8) plane.

Abstract: A MOSFET includes: a substrate made of silicon carbide and having a first trench and a second trench formed therein, the first trench having an opening at the main surface side, the second trench having an opening at the main surface side and being shallower than the first trench; a gate insulating film; a gate electrode; and a source electrode disposed on and in contact with a wall surface of the second trench. The substrate includes a source region, a body region, and a drift region. The first trench is formed to extend through the source region and the body region and reach the drift region. The second trench is formed to extend through the source region and reach the body region.

Abstract: A MOSFET includes: a substrate provided with a trench having a side wall surface having an off angle of not less than 50° and not more than 65° relative to a {0001} plane; an oxide film; and a gate electrode. The substrate includes a source region, a body region, and a drift region formed to sandwich the body region between the source region and the drift region. The source region and the body region are formed by means of ion implantation. The body region has an internal region sandwiched between the source region and the drift region and having a thickness of 1 ?m or smaller in a direction perpendicular to a main surface thereof. The body region has an impurity concentration of 3×1017 cm?3 or greater.

Abstract: A substrate has a surface made of a semiconductor having a hexagonal single-crystal structure of polytype 4H. The surface of the substrate is constructed by alternately providing a first plane having a plane orientation of (0-33-8), and a second plane connected to the first plane and having a plane orientation different from the plane orientation of the first plane. A gate insulating film is provided on the surface of the substrate. A gate electrode is provided on the gate insulating film.

Abstract: A method for manufacturing a MOSFET includes the steps of: forming a gate oxide film on an active layer, forming a gate electrode on the gate oxide film, forming a source contact electrode in ohmic contact with the active layer, and forming an interlayer insulating film made of silicon dioxide so as to cover the gate electrode after the source contact electrode is formed. The step of forming a source contact electrode includes the steps of forming a metal layer including aluminum so as to be in contact with the active layer, and alloying the metal layer.