Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer 4 that constitutes an electron transit layer, a second nitride semiconductor layer 5 that is formed on the first nitride semiconductor layer, is larger in bandgap than the first nitride semiconductor layer, and constitutes an electron supply layer, and a gate portion 20 that is formed on the second nitride semiconductor layer. The gate portion 20 includes a first semiconductor gate layer 21 of a ridge shape that is disposed on the second nitride semiconductor layer 5 and is constituted of a nitride semiconductor containing an acceptor type impurity, a second semiconductor gate layer 22 that is formed on the first semiconductor gate layer 21 and is constituted of a nitride semiconductor with a larger bandgap than the first semiconductor gate layer 21, and a gate electrode 23 that is formed on the second semiconductor gate layer 22 and is in Schottky junction with the second semiconductor gate layer 22.

Abstract: A nitride semiconductor device includes: an electron transit layer; an electron supply layer that is formed on the electron transit layer and that has a band gap which is larger than that of the electron transit layer; a dielectric layer that is formed on the electron supply layer; and an electrode that has a contact part which is in electrical contact with the electron supply layer via at least an opening passing through the dielectric layer. The contact part has: an inclined surface that is inclined so as to decrease in width toward the electron transit layer; a tip surface that is in contact with the bottom face of the opening; and a curved surface that is provided between the tip surface and the inclined surface and that is curved so as to protrude toward the electron transit layer.

Abstract: A nitride semiconductor device includes: an electron supply layer; a gate layer, a gate electrode; a passivation layer; a source electrode; a drain electrode; an active region; and an inactive region that is adjacent to the active region in a second direction orthogonal to a first direction in plan view. The gate layer includes a main gate part extending in the second direction in the active region, a subgate part extending in the second direction to be continuous with the main gate part in the inactive region, and a protruding part protruding from the subgate part toward a drain opening in the first direction.

Abstract: A nitride semiconductor device includes a passivation layer, which covers a gate layer, and a field plate electrode, which is arranged on the passivation layer. The gate layer includes a gate layer main body and a drain-side extension. The passivation layer includes a first part overlapping both the drain-side extension and the field plate electrode in plan view, a second part continuous with the first part and located between the drain-side extension and the drain opening, and a first step located in a region including a boundary of the first part and the second part. The first part has a first thickness from the upper step surface to an upper surface of the drain-side extension. The second part has a second thickness from the lower step surface to an upper surface of the electron supply layer. The first thickness is greater than the second thickness.

Abstract: A nitride semiconductor device includes: a first nitride semiconductor layer made of a nitride semiconductor; a second nitride semiconductor layer made of a nitride semiconductor having a bandgap larger than that of the first nitride semiconductor layer; a gate electrode located above the second nitride semiconductor layer; and a source electrode and a drain electrode formed on the second nitride semiconductor layer, wherein the first nitride semiconductor layer includes one or more stacked bodies, each of which includes a doped layer as a carbon-doped gallium nitride layer, and a non-doped layer as a non-doped gallium nitride layer formed on the doped layer, and wherein in a region below at least one of the gate electrode or the drain electrode, the number of dislocation lines passing through a top surface of the non-doped layer is smaller than the number of dislocation lines passing through a bottom surface of the non-doped layer.

Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer 13 that constitutes an electron transit layer, a second nitride semiconductor layer 14 that is formed on the first nitride semiconductor layer and constitutes an electron supply layer, a nitride semiconductor gate layer 15 that is disposed on the second nitride semiconductor layer, has a ridge portion 15A at least at a portion thereof, and contains an acceptor type impurity, a gate electrode 4 that is disposed at least on the ridge portion of the nitride semiconductor gate layer, a source electrode 3 that is disposed on the second nitride semiconductor layer and has a source principal electrode portion 3A parallel to the ridge portion, and a drain electrode 5 that is disposed on the second nitride semiconductor layer and has a drain principal electrode portion 5A parallel to the ridge portion.

Abstract: A nitride semiconductor device includes a source electrode that is in contact with a second nitride semiconductor layer via a first opening portion and with which a portion is formed above a passivation film and a drain electrode that is in contact with the second nitride semiconductor layer via a second opening portion and with which a portion is formed above the passivation film such as to oppose the source electrode across a ridge portion, and the third nitride semiconductor layer has, between a ridge portion side end of the first opening portion and a first opening portion end of the ridge portion and/or between a ridge portion side end of the drain electrode and a second opening portion end of the ridge portion, an extension portion that extends outward from a portion below a thickness intermediate position of at least one side surface of the ridge portion.

Abstract: There is provided a nitride semiconductor device that includes a first nitride semiconductor layer configured as an electron transit layer, a second nitride semiconductor layer formed on the first nitride semiconductor layer and configured as an electron supply layer, a ridge-shaped nitride semiconductor gate layer disposed on the second nitride semiconductor layer and including an acceptor-type impurity, and a gate electrode formed on the nitride semiconductor gate layer. The gate electrode includes a first metal film that is formed on the nitride semiconductor gate layer and is mainly made of Ti, and a second metal film that is formed on the first metal film and is made of TiN.

Abstract: There is provided a nitride semiconductor device that includes a first nitride semiconductor layer configured as an electron transit layer, a second nitride semiconductor layer formed on the first nitride semiconductor layer and configured as an electron supply layer, a ridge-shaped nitride semiconductor gate layer disposed on the second nitride semiconductor layer and including an acceptor-type impurity, and a gate electrode formed on the nitride semiconductor gate layer. The gate electrode includes a first metal film that is formed on the nitride semiconductor gate layer and is mainly made of Ti, and a second metal film that is formed on the first metal film and is made of TiN.

Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer 4 that constitutes an electron transit layer, a second nitride semiconductor layer 5 that is formed on the first nitride semiconductor layer and constitutes an electron supply layer, and a gate portion 20 that is formed on the second nitride semiconductor layer. The gate portion 20 includes a semiconductor gate layer 21 of a ridge shape that is formed on the second nitride semiconductor layer and is constituted of a nitride semiconductor containing an acceptor type impurity and a gate electrode 22 that is formed on the semiconductor gate layer. The semiconductor gate layer is constituted of a gate layer main body portion 211 that is formed on the second nitride semiconductor layer and an upper protruding portion 212 that is formed on a width intermediate portion of an upper surface of the gate layer main body portion, and the gate electrode is formed on a top surface of the upper protruding portion.

Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer that constitutes an electron transit layer, a second nitride semiconductor layer that is formed on the first nitride semiconductor layer, is larger in bandgap than the first nitride semiconductor layer, and constitutes an electron supply layer, a gate portion that is formed on the second nitride semiconductor layer, and a source electrode and a drain electrode that, on the second nitride semiconductor layer, are opposingly disposed across the gate portion. The gate portion includes a third nitride semiconductor layer of a ridge shape that is formed on the second nitride semiconductor layer and contains an acceptor type impurity and a gate electrode that is formed on the third nitride semiconductor layer. A film thickness of the third nitride semiconductor layer is greater than 100 nm.

Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer 13 that constitutes an electron transit layer, a second nitride semiconductor layer 14 that is formed on the first nitride semiconductor layer and constitutes an electron supply layer, a nitride semiconductor gate layer 15 that is disposed on the second nitride semiconductor layer, has a ridge portion 15A at least at a portion thereof, and contains an acceptor type impurity, a gate electrode 4 that is disposed at least on the ridge portion of the nitride semiconductor gate layer, a source electrode 3 that is disposed on the second nitride semiconductor layer and has a source principal electrode portion 3A parallel to the ridge portion, and a drain electrode 5 that is disposed on the second nitride semiconductor layer and has a drain principal electrode portion 5A parallel to the ridge portion.

Abstract: Disclosed herein is a nitride semiconductor apparatus including an electron transit layer including a nitride semiconductor, an electron supply layer that is formed on the electron transit layer and includes a nitride semiconductor with a band gap larger than a band gap of the electron transit layer, a step layer that is formed on part of the electron supply layer and includes a nitride semiconductor with a band gap smaller than the band gap of the electron supply layer, a gate layer that is formed on part of the electron supply layer or part of the step layer and contains acceptor impurities, a gate electrode formed on the gate layer, and a source electrode and a drain electrode that are in contact with the electron supply layer. The step layer includes extension portions extending outside of the gate layer in plan view. The extension portions each include an undoped layer.

Abstract: A nitride semiconductor device 1 includes a first nitride semiconductor layer 4 that constitutes an electron transit layer, a second nitride semiconductor layer 5 that is formed on the first nitride semiconductor layer, is larger in bandgap than the first nitride semiconductor layer, and constitutes an electron supply layer, and a gate portion 20 that is formed on the second nitride semiconductor layer. The gate portion 20 includes a first semiconductor gate layer 21 of a ridge shape that is disposed on the second nitride semiconductor layer 5 and is constituted of a nitride semiconductor containing an acceptor type impurity, a second semiconductor gate layer 22 that is formed on the first semiconductor gate layer 21 and is constituted of a nitride semiconductor with a larger bandgap than the first semiconductor gate layer 21, and a gate electrode 23 that is formed on the second semiconductor gate layer 22 and is in Schottky junction with the second semiconductor gate layer 22.

Abstract: A semiconductor device includes: a back barrier layer containing AlXGa(1-X)N (0<X?1); an electron transit layer containing AlaInbGa(1-a-b)N (0?a+b?1) and formed on the back barrier layer; a top barrier layer containing AlYGa(1-Y)N (0<Y?1) and formed on the electron transit layer; an electron supply layer containing AlZGa(1-Z)N (0<Z?1) and formed on the top barrier layer, the electron supply layer having an opening to expose the top barrier layer; a two-dimensional electron gas region formed in an area of a surface layer portion of the electron transit layer, the area opposing the electron supply layer with the top barrier layer interposed between the electron supply layer and the area; a gate insulating layer formed in the opening of the electron supply layer; and a gate electrode layer formed on the gate insulating layer and opposing the electron transit layer with the gate insulating layer interposed therebetween.

Abstract: A nitride semiconductor device includes: an electron transit layer including GaxIn1-xN (0<x?1); an electron supply layer formed on the electron transit layer and including AlyIn1-yN (0<y?1); a gate insulating film formed to pass through the electron supply layer to contact the electron transit layer; and a gate electrode facing the electron transit layer with the gate insulating film interposed therebetween, wherein, in the electron transit layer, a portion contacting the gate insulating film and a portion contacting the electron transit layer are flush with each other.

Abstract: There is provided a nitride semiconductor device that includes a first nitride semiconductor layer configured as an electron transit layer, a second nitride semiconductor layer formed on the first nitride semiconductor layer and configured as an electron supply layer, a ridge-shaped nitride semiconductor gate layer disposed on the second nitride semiconductor layer and including an acceptor-type impurity, and a gate electrode formed on the nitride semiconductor gate layer. The gate electrode includes a first metal film that is formed on the nitride semiconductor gate layer and is mainly made of Ti, and a second metal film that is formed on the first metal film and is made of TiN.

Abstract: A nitride semiconductor device includes: an electron transit layer including GaxIn1-xN (0<x?1); an electron supply layer formed on the electron transit layer and including AlyIn1-yN (0<y?1); a gate insulating film formed to pass through the electron supply layer to contact the electron transit layer; and a gate electrode facing the electron transit layer with the gate insulating film interposed therebetween, wherein, in the electron transit layer, a portion contacting the gate insulating film and a portion contacting the electron transit layer are flush with each other.

Abstract: A semiconductor device includes: a back barrier layer containing AlXGa(1-X)N (0<X?1); an electron transit layer containing AlaInbGa(1-a-b)N (0?a+b?1) and formed on the back barrier layer; a top barrier layer containing AlYGa(1-Y)N (0<Y?1) and formed on the electron transit layer; an electron supply layer containing AlZGa(1-Z)N (0<Z?1) and formed on the top barrier layer, the electron supply layer having an opening to expose the top barrier layer; a two-dimensional electron gas region formed in an area of a surface layer portion of the electron transit layer, the area opposing the electron supply layer with the top barrier layer interposed between the electron supply layer and the area; a gate insulating layer formed in the opening of the electron supply layer; and a gate electrode layer formed on the gate insulating layer and opposing the electron transit layer with the gate insulating layer interposed therebetween.

Abstract: A nitride semiconductor device includes: an electron transit layer including GaxIn1-xN (0<x?1); an electron supply layer formed on the electron transit layer and including AlyIn1-yN (0<y?1); a gate insulating film formed to pass through the electron supply layer to contact the electron transit layer; and a gate electrode facing the electron transit layer with the gate insulating film interposed therebetween, wherein, in the electron transit layer, a portion contacting the gate insulating film and a portion contacting the electron transit layer are flush with each other.