Rohm Co., Ltd.

Shinya Takado

Norikazu Ito

Atsushi Yamaguchi

Minoru Akutsu

Hirotaka Otake

Taketoshi Tanaka

Kentaro Chikamatsu

Junichi Kashiwagi

Kazuya Nagase

A nitride semiconductor deviceincludes 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.

Nitride semiconductor device

A nitride semiconductor deviceincludes a first nitride semiconductor layerthat constitutes an electron transit layer, a second nitride semiconductor layerthat 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 portionthat is formed on the second nitride semiconductor layer. The gate portionincludes a first semiconductor gate layerof a ridge shape that is disposed on the second nitride semiconductor layerand is constituted of a nitride semiconductor containing an acceptor type impurity, a second semiconductor gate layerthat is formed on the first semiconductor gate layerand is constituted of a nitride semiconductor with a larger bandgap than the first semiconductor gate layer, and a gate electrodethat is formed on the second semiconductor gate layerand is in Schottky junction with the second semiconductor gate layer

A nitride semiconductor deviceincludes a first nitride semiconductor layerthat constitutes an electron transit layer, a second nitride semiconductor layerthat is formed on the first nitride semiconductor layer and constitutes an electron supply layer, a nitride semiconductor gate layerthat is disposed on the second nitride semiconductor layer, has a ridge portionA at least at a portion thereof, and contains an acceptor type impurity, a gate electrodethat is disposed at least on the ridge portion of the nitride semiconductor gate layer, a source electrodethat is disposed on the second nitride semiconductor layer and has a source principal electrode portionA parallel to the ridge portion, and a drain electrodethat is disposed on the second nitride semiconductor layer and has a drain principal electrode portionA parallel to the ridge portion. A length direction of the ridge portion is a [110] direction of a semiconductor crystal structure that constitutes the second nitride semiconductor layer.

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.

Nitride semiconductor device and method of manufacturing the same

A semiconductor device includes: a back barrier layer containing AlGaN (0&#x3c;X&#x2264;1); an electron transit layer containing AlInGaN (0&#x2264;a+b&#x2264;1) and formed on the back barrier layer; a top barrier layer containing AlGaN (0&#x3c;Y&#x2264;1) and formed on the electron transit layer; an electron supply layer containing AlGaN (0&#x3c;Z&#x2264;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.

Semiconductor device and manufacturing method thereof

A nitride semiconductor device includes: an electron transit layer including GaxIn1-xN (0&#x3c;x&#x2264;1); an electron supply layer formed on the electron transit layer and including AlyIn1-yN (0&#x3c;y&#x2264;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.

Nitride semiconductor device and method for manufacturing the same

A nitride semiconductor device includes: an electron transit layer including GaInN (0&#x3c;x&#x2264;1); an electron supply layer formed on the electron transit layer and including AlInN (0&#x3c;y&#x2264;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.

A nitride semiconductor element capable of accommodating GaN electron transfer layers of a wide range of thickness, so as to allow greater freedom of device design, and a nitride semiconductor element package with excellent voltage tolerance performance and reliability. On a substrate, a buffer layer including an AlN layer, a first AlGaN layer and a second AlGaN layer is formed. On the buffer layer, an element action layer including a GaN electron transfer layer and an AlGaN electron supply layer is formed. Thus, an HEMT element is constituted.

Nitride semiconductor element and nitride semiconductor package

A nitride semiconductor device includes: an electron transit layer including GaInN (0&#x3c;x&#x2266;1); an electron supply layer formed on the electron transit layer and including AlInN (0&#x3c;y&#x2266;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.

A nitride semiconductor element capable of accommodating GaN electron transfer layers of a wide range of thickness, so as to allow greater freedom of device design, and a nitride semiconductor element package with excellent voltage tolerance performance and reliability. On a substrate, a buffer layer including an AlN layer, a first AlGaN layer (with an average Al component of 50%) and a second AlGaN layer (with an average Al component of 20%) is formed. On the buffer layer, an element action layer including a GaN electron transfer layer and an AlGaN electron supply layer is formed. Thus, an HEMT element is constituted.

A semiconductor laser device generates blue-violet light with an emission wavelength of 400 to 410 nm. The device includes an n-type group III nitride semiconductor layer, an active layer laminated on the n-type semiconductor layer and having an InGaN quantum well layer, a p-type group III nitride semiconductor layer laminated on the active layer, and a transparent electrode contacting the p-type semiconductor layer and serving as a clad. The n-type semiconductor layer includes an n-type clad layer and an n-type guide layer disposed between the clad layer and the active layer. The guide layer includes a superlattice layer in which an InGaN layer and an AlGaN layer (0&#x2266;X&#x3c;1) are laminated periodically, the superlattice layer contacting the active layer and having an average refractive index of 2.6 or lower. The In composition of the InGaN layer is lower than that of the InGaN quantum well layer.

Semiconductor laser device

A nitride semiconductor element includes a Si substrate; a buffer layer including (a) an AlN layer formed on a primary surface of the Si substrate; and (b) an AlGaN deposit layer formed by laminating multiple AlGaN layers on the AlN layer and having a total thickness ranging from 100 nm to 500 nm; a GaN electron transfer layer formed on the AlGaN deposit layer and having a thickness ranging from 500 nm to 2000 nm provided that the GaN electron transfer layer is thicker than the AlGaN deposit layer; and an AlGaN electron supply layer formed on the GaN electron transfer layer, wherein the AlGaN deposit layer includes an AlGaN layer that is provided closer to the AlN layer and has an Al component that ranges from about 40% to about 60%, and a reference AlGaN layer that has an Al component (%) that is lower than that of the AlGaN layer.

A semiconductor laser device generates blue-violet light with an emission wavelength of 400 to 410 nm. The device includes an n-type group III nitride semiconductor layer, an active layer laminated on the n-type semiconductor layer and having an InGaN quantum well layer, a p-type group III nitride semiconductor layer laminated on the active layer, and a transparent electrode contacting the p-type semiconductor layer and serving as a clad. The n-type semiconductor layer includes an n-type clad layer and an n-type guide layer disposed between the clad layer and the active layer. The guide layer includes a superlattice layer in which an InGaN layer and an AlGaN layer (0&#x2266;x&#x3c;1) are laminated periodically, the superlattice layer contacting the active layer and having an average refractive index of 2.6 or lower. The In composition of the InGaN layer is lower than that of the InGaN quantum well layer.

An inventive nitride semiconductor device includes: a substrate; a first buffer layer provided on the substrate, and having a superlattice structure which includes two types of Group III nitride semiconductor sublayers having different compositions and alternately stacked in pairs; a second buffer layer provided on the first buffer layer in contact with the first buffer layer, and having a superlattice structure which includes two types of Group III nitride semiconductor sublayers having different compositions and alternately stacked in pairs; and a device operation layer of a Group III nitride semiconductor provided on the second buffer layer; wherein an average lattice constant LCof the first buffer layer, an average lattice constant LCof the second buffer layer and an average lattice constant LCof the device operation layer satisfy the following expression (1):LC1&#x3c;LC2&#x3c;LC3&#x2003;&#x2003;(1).

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Kyoto, Japan

Shinya Takado