Abstract: A semiconductor device of an embodiment includes a first GaN-based semiconductor layer, a second GaN-based semiconductor layer provided on the first GaN-based semiconductor layer and having a larger bandgap than the first GaN-based semiconductor layer, a source electrode provided on the second GaN-based semiconductor layer, a drain electrode provided on the second GaN-based semiconductor layer, a recess provided between the source electrode and the drain electrode in the second GaN-based semiconductor layer, a gate insulating film provided on a surface of the recess, and a gate electrode provided on the gate insulating film and having an end portion in a gate width direction, located in the recess.

Abstract: According to one embodiment, a method for manufacturing a semiconductor device is disclosed. The method can include forming a trench and exposing a portion of a first film at a bottom portion of the trench by removing a portion of a second film by performing dry etching using a gas including a first element. The second film is provided on the first film. The first film includes Alx1Ga1-x1N (0?x1<1). The second film includes Alx2Ga1-x2N (0<x2<1 and x1<x2). The method can include performing heat treatment while causing the portion being exposed of the first film to contact an atmosphere including NH3, forming an insulating film on the portion of the first film after the heat treatment, and forming an electrode on the insulating film.

Abstract: According to one embodiment, a semiconductor device includes a first electrode, a second electrode, a third electrode, a first layer, a second layer, a third layer, and an insulating layer. A position of the third electrode is between a position of the first electrode and a position of the second electrode. The first layer includes at least one of Alx1Ga1-x1N (0<x1<1) or p-type Alz1Ga1-z1N (0?z1<1) and has a first surface, a second surface, and a third surface. The second layer includes Alx2Ga1-x2N (0?x2<1 and x2<x1) and includes a first partial region, a second partial region, and a third partial region. The third layer includes Alx3Ga1-x3N (0<x3<1 and x2<x3) and includes a fourth partial region, a fifth partial region, and a sixth partial region.

Abstract: According to one embodiment, a semiconductor device includes a first electrode, a second electrode, a third electrode, a first layer, a second layer, a third layer, and an insulating layer. A position of the third electrode is between a position of the first electrode and a position of the second electrode. The first layer includes at least one of Alx1Ga1-x1N (0<x1<1) or p-type Alz1Ga1-z1N (0?z1<1) and has a first surface, a second surface, and a third surface. The second layer includes Alx2Ga1-x2N (0?x2<1 and x2<x1) and includes a first partial region, a second partial region, and a third partial region. The third layer includes Alx3Ga1-x3N (0<x3<1 and x2<x3) and includes a fourth partial region, a fifth partial region, and a sixth partial region.

Abstract: According to one embodiment, a semiconductor device includes a first electrode, a first region, and a first insulating layer. The first electrode includes a first electrode portion. The first region contains Ga and N. The first region includes a first subregion, a second subregion, and a third subregion. The first subregion and the third subregion contain at least one first element selected from the group consisting of Ar, B, P, N, and Fe. The first subregion is located between the first electrode portion and the second subregion in a first direction. The second subregion does not contain the first element, or concentration of the first element in the second subregion is lower than concentration of the first element in the first subregion and lower than concentration of the first element in the third subregion. The first insulating layer is provided between the first electrode and the first region.

Abstract: According to one embodiment, a semiconductor device includes a first electrode, a second electrode, a third electrode, a first layer, a second layer, a third layer, and an insulating layer. A position of the third electrode is between a position of the first electrode and a position of the second electrode. The first layer includes at least one of Alx1Ga1-x1N (0<x1<1) or p-type Alz1Ga1-z1N (0?z1<1) and has a first surface, a second surface, and a third surface. The second layer includes Alx2Ga1-x2N (0?x2<1 and x2<x1) and includes a first partial region, a second partial region, and a third partial region. The third layer includes Alx3Ga1-x3N (0<x3<1 and x2<x3) and includes a fourth partial region, a fifth partial region, and a sixth partial region.

Abstract: According to one embodiment, a semiconductor substrate includes a first semiconductor layer including Alx1Ga1-x1N (0<x1?1) and including carbon and oxygen, and a second semiconductor layer including Alx2Ga1-x2N (0<x2<x1) and including carbon and oxygen. A second ratio of a carbon concentration of the second semiconductor layer to an oxygen concentration of the second semiconductor layer is 730 or more.

Abstract: According to one embodiment, a semiconductor device includes first to third electrodes, and first to third semiconductor regions. The third electrode is separated from the second electrode in a first direction. The first semiconductor region includes a first partial region separated from the first electrode, a second partial region separated from the second electrode, and a third partial region separated from the third electrode. The second semiconductor region includes a fourth partial region positioned between the first electrode and the first partial region, a fifth partial region positioned between the second electrode and the second partial region, and a sixth partial region positioned between the third electrode and the third partial region. The third semiconductor region includes a seventh partial region positioned between the second electrode and the fifth partial region and an eighth partial region positioned between the third electrode and the sixth partial region.

Abstract: According to one embodiment, a semiconductor device includes first, second and third electrodes, first, second, third, and fourth semiconductor regions, and an insulating portion. The first electrode includes first and second electrode portions. The first semiconductor region includes first, second, and third semiconductor portions. The first semiconductor portion is provided between the first electrode portion and the second electrode. The second semiconductor portion is provided between the second electrode portion and the third electrode. The third semiconductor portion is provided between the first and second semiconductor portions. The second semiconductor region is provided between the first semiconductor portion and the second electrode. The third semiconductor region is positioned between the second semiconductor region and the third electrode. The insulating portion includes first and second insulating regions.

Abstract: A semiconductor device according to an embodiment includes a first GaN based semiconductor layer of a first conductive type, a second GaN based semiconductor layer of the first conductive type provided above the first GaN based semiconductor layer, a third GaN based semiconductor layer of a second conductive type provided above a part of the second GaN based semiconductor layer, a epitaxially grown fourth GaN based semiconductor layer of the first conductive type provided above the third GaN based semiconductor layer, a gate insulating film provided on the second, third, and fourth GaN based semiconductor layer, a gate electrode provided on the gate insulating film, a first electrode provided on the fourth GaN based semiconductor layer, a second electrode provided at the side of the first GaN based semiconductor layer opposite to the second GaN based semiconductor layer, and a third electrode provided on the second GaN based semiconductor layer.

Abstract: A semiconductor device according to an embodiment includes: a substrate having a first plane and a second plane provided on the opposite side of the first plane; a first nitride semiconductor layer provided on the first plane; source electrodes provided on the first nitride semiconductor layer; drain electrodes provided on the first nitride semiconductor layer, each of the drain electrodes provided between the source electrodes; gate electrodes provided on the first nitride semiconductor layer, each of the gate electrodes provided between each of the source electrodes and each of the drain electrodes; a first wire provided on the second plane and electrically connected to the source electrodes; a second wire electrically connected to the drain electrodes; a third wire provided on the second plane and electrically connected to the gate electrodes; and an insulating interlayer provided between the first nitride semiconductor layer and the second wire.

Abstract: A semiconductor device includes: a first GaN based semiconductor layer; a second GaN based semiconductor layer disposed on the first layer and having a bandgap larger than that of the first layer; a first electrode disposed on the second layer; a second electrode disposed on the second layer; a p-type third GaN based semiconductor layer disposed between the first electrode and the second electrode on the second layer; a third electrode disposed on the third layer; a p-type fourth GaN based semiconductor layer disposed directly on the second layer and disposed separated from the third layer; a first insulating film disposed on the fourth layer; and a first field plate electrode disposed interposing the first insulating film in a space with the fourth layer, the first field plate electrode being separated from the fourth layer, and the first field plate electrode electrically connected to the first electrode.

Abstract: According to one embodiment, a method for manufacturing a semiconductor device is disclosed. The method can include forming a trench and exposing a portion of a first film at a bottom portion of the trench by removing a portion of a second film by performing dry etching using a gas including a first element. The second film is provided on the first film. The first film includes Alx1Ga1-x1N (0?x1<1). The second film includes Alx2Ga1-x2N (0<x2<1 and x1<x2). The method can include performing heat treatment while causing the portion being exposed of the first film to contact an atmosphere including NH3, forming an insulating film on the portion of the first film after the heat treatment, and forming an electrode on the insulating film.

Abstract: A semiconductor device according to an embodiment includes: a first GaN based semiconductor layer; a second GaN based semiconductor layer disposed on the first GaN based semiconductor layer and having a bandgap larger than that of the first GaN based semiconductor layer; a source electrode disposed on the second GaN based semiconductor layer; a drain electrode disposed on the second GaN based semiconductor layer; a p-type third GaN based semiconductor layer disposed between the source electrode and the drain electrode on the second GaN based semiconductor layer; a gate electrode disposed on the third GaN based semiconductor layer; and a p-type fourth GaN based semiconductor layer disposed between the gate electrode and the drain electrode on the second GaN based semiconductor layer and disposed separated from the third GaN based semiconductor layer.

Abstract: According to one embodiment, a semiconductor device includes a first semiconductor layer; a second semiconductor layer having a larger band gap than the first semiconductor layer; a third semiconductor layer having a smaller band gap than the second semiconductor layer; a first electrode being in contact with the third semiconductor layer; a second electrode being in contact with the third semiconductor layer; and a third electrode provided between the third semiconductor layer in contact with the first electrode, the second semiconductor layer directly below the first electrode, and the first semiconductor layer directly below the first electrode, and the third semiconductor layer in contact with the second electrode, the second semiconductor layer directly below the second electrode, and the first semiconductor layer directly below the second electrode, being in contact with the third semiconductor layer, the second semiconductor layer, and the first semiconductor layer via insulating film.

Abstract: A semiconductor device according to an embodiment includes a first nitride semiconductor layer; a source electrode provided on the first nitride semiconductor layer; a drain electrode provided on the first nitride semiconductor layer; a gate electrode provided between the source electrode and the drain electrode; a first film provided between the source electrode and the gate electrode and between the gate electrode and the drain electrode; and a second film provided on the first film. The first film is provided on the first nitride semiconductor layer. The first film has a lower hydrogen diffusion coefficient than a hydrogen diffusion coefficient of a silicon oxide film.

Abstract: A semiconductor device according to an embodiment includes: a substrate having a first plane and a second plane provided on the opposite side of the first plane; a first nitride semiconductor layer provided on the first plane; source electrodes provided on the first nitride semiconductor layer; drain electrodes provided on the first nitride semiconductor layer, each of the drain electrodes provided between the source electrodes; gate electrodes provided on the first nitride semiconductor layer, each of the gate electrodes provided between each of the source electrodes and each of the drain electrodes; a first wire provided on the second plane and electrically connected to the source electrodes; a second wire electrically connected to the drain electrodes; a third wire provided on the second plane and electrically connected to the gate electrodes; and an insulating interlayer provided between the first nitride semiconductor layer and the second wire.

Abstract: A semiconductor device according to an embodiment includes a first GaN based semiconductor layer of a first conductive type, a second GaN based semiconductor layer of the first conductive type provided above the first GaN based semiconductor layer, a third GaN based semiconductor layer of a second conductive type provided above a part of the second GaN based semiconductor layer, a epitaxially grown fourth GaN based semiconductor layer of the first conductive type provided above the third GaN based semiconductor layer, a gate insulating film provided on the second, third, and fourth GaN based semiconductor layer, a gate electrode provided on the gate insulating film, a first electrode provided on the fourth GaN based semiconductor layer, a second electrode provided at the side of the first GaN based semiconductor layer opposite to the second GaN based semiconductor layer, and a third electrode provided on the second GaN based semiconductor layer.

Abstract: A semiconductor device according to an embodiments controls a gate voltage to be applied to a gate electrode of a junction field effect transistor including a source electrode, a drain electrode, and the gate electrode, the transistor having a first threshold voltage at which the transistor is turned on, and a second threshold at which conductivity modulation occurs in the transistor so as to make the gate voltage equal to or higher than the second threshold voltage when a forward current in a direction from the drain electrode toward the source electrode flows, and so as to make the time variation in gate voltage have a point from which the rate of the time variation starts decreasing at a voltage between the second threshold voltage and the first threshold voltage when the forward current to be shut down.

Abstract: A semiconductor device according to an embodiment includes a first nitride semiconductor layer; a source electrode provided on the first nitride semiconductor layer; a drain electrode provided on the first nitride semiconductor layer; a gate electrode provided between the source electrode and the drain electrode; a first film provided between the source electrode and the gate electrode and between the gate electrode and the drain electrode; and a second film provided on the first film. The first film is provided on the first nitride semiconductor layer. The first film has a lower hydrogen diffusion coefficient than a hydrogen diffusion coefficient of a silicon oxide film.