Fujitsu Corporation

Transphorm Japan, Inc.

Tetsuro Ishiguro

Atsushi Yamada

Norikazu Nakamura

Junji Kotani

Kozo Makiyama

Kenji Imanishi

Shuichi Tomabechi

A compound semiconductor device includes a first compound semiconductor layer containing a p-type impurity, a second compound semiconductor layer disposed over the first compound semiconductor layer and containing InGaN, an electron transit layer disposed over the second compound semiconductor layer, and an electron supply layer disposed over the electron transit layer.

Compound semiconductor device with high power and reduced off-leakage and method for manufacturing the same

Disclosed is a compound semiconductor device that includes an electron transit layer; an electron supply layer disposed above the electron transit layer, and including a first region and a second region, the second region having a composition higher in Al than the first region and covering the first region from at least a bottom part of the second region; a first electrode disposed above the first region; and a second electrode disposed above the second region.

Compound semiconductor device and fabrication method

A compound semiconductor device includes: a carrier transit layer; a carrier supply layer that is formed over the carrier transit layer and is made of InAlN; and a spacer layer that is formed between the carrier transit layer and the carrier supply layer and is made of at least one of AlGaN and InAlGaN.

Compound semiconductor device and manufacturing method thereof

A semiconductor crystal substrate includes a first buffer layer formed of a nitride semiconductor over a substrate, a second buffer layer formed of a nitride semiconductor on the first buffer layer, a first semiconductor layer formed of a nitride semiconductor on or over the second buffer layer, and a second semiconductor layer formed of a nitride semiconductor on the first semiconductor layer. The Fe concentration of the first buffer layer is higher than the C concentration of the first buffer layer. The C concentration of the second buffer layer is higher than the Fe concentration of the second buffer layer.

Semiconductor crystal substrate with Fe doping

A compound semiconductor device includes: a first layer of nitride semiconductor, the first layer being doped with Fe; a channel layer of nitride semiconductor above the first layer; and a barrier layer of nitride semiconductor above the channel layer, wherein the channel layer includes: a two-dimensional electron gas region in which the two-dimensional electron gas exists; and an Al-containing region between the two-dimensional electron gas region and the first layer, an Al concentration in the Al-containing region being 5&#xd7;10atoms/cmor more and less than 1&#xd7;10atoms/cm.

Compound semiconductor device and method of manufacturing the same

A compound semiconductor device includes: a GaN-based channel layer; a barrier layer of nitride semiconductor above the channel layer; and a cap layer of nitride semiconductor above the barrier layer, wherein the cap layer includes: a first region doped with Fe; and a second region above the first region, a concentration of Fe in the second region being lower than a concentration of Fe in the first region.

Gallium nitride based high electron mobility transistor (GaN-HEMT) device with an iron-doped cap layer and method of manufacturing the same

A compound semiconductor device includes: an electron transit layer; an electron supply layer formed over the electron transit layer; and a GaN cap layer formed over the electron supply layer, wherein the electron supply layer includes a first layer made of i-type AlGaN (0&#x3c;x&#x3c;1) and a second layer made of i-type AlGaN (x&#x3c;y&#x2266;1) and formed over the first layer.

Compound semiconductor device and method for manufacturing the same

An embodiment of a method of manufacturing a compound semiconductor device includes: forming an initial layer over a substrate; forming a buffer layer over the initial layer; forming an electron transport layer and an electron supply layer over the buffer layer; and forming a gate electrode, a source electrode and a gate electrode over the electron supply layer. The forming an initial layer includes: forming a first compound semiconductor film with a flow rate ratio being a first value, the flow rate ratio being a ratio of a flow rate of a V-group element source gas to a flow rate of a III-group element source gas; and forming a second compound semiconductor film with the flow rate ratio being a second value different from the first value over the first compound semiconductor film. The method further includes forming an Fe-doped region between the buffer layer and the electron transport layer.

A compound semiconductor device includes: a substrate; and a compound semiconductor lamination structure formed over the substrate, the compound semiconductor lamination structure including a buffer layer containing an impurity, and an active layer formed over the buffer layer.

Compound semiconductor device, power source device and high frequency amplifier and method for manufacturing the same

A semiconductor apparatus includes: a substrate; a buffer layer formed on the substrate; a strained layer superlattice buffer layer formed on the buffer layer; an electron transit layer formed of a semiconductor material on the strained layer superlattice buffer layer; and an electron supply layer formed of a semiconductor material on the electron transit layer; the strained layer superlattice buffer layer being an alternate stack of first lattice layers including AlN and second lattice layers including GaN; the strained layer superlattice buffer layer being doped with one, or two or more impurities selected from Fe, Mg and C.

Semiconductor apparatus

A semiconductor apparatus includes a buffer layer formed on a substrate; an SLS (Strained Layer Supperlattice) buffer layer formed on the buffer layer; an electron transit layer formed on the SLS buffer layer and formed of a semiconductor material; and an electron supply layer formed on the electron transit layer and formed of a semiconductor material. Further, the buffer layer is formed of AlGaN and includes two or more layers with different Al composition ratios, the SLS buffer layer is formed by alternately laminating a first lattice layer including AlN and a second lattice layer including GaN, and the Al composition ratio in one of the layers of the buffer layer being in contact with the SLS buffer layer is greater than or equal to an Al effective composition ratio in the SLS buffer layer.

A semiconductor apparatus includes a substrate; a buffer layer formed on the substrate; a first semiconductor layer formed on the buffer layer; and a second semiconductor layer formed on the first semiconductor layer. Further, the buffer layer is formed of AlGaN and doped with Fe, the buffer layer includes a plurality of layers having different Al component ratios from each other, and the Al component ratio of a first layer is greater than the Al component ratio of a second layer and a Fe concentration of the first layer is less than the Fe concentration of the second layer, the first and second layers being included in the plurality of layers, and the first layer being formed on a substrate side of the second layer.

Semiconductor apparatus having nitride semiconductor buffer layer doped with at least one of Fe, Si, and C

A semiconductor device includes a first semiconductor layer formed on a substrate, the first semiconductor containing an impurity element; a second semiconductor layer formed on the first semiconductor layer; a third semiconductor layer formed on the second semiconductor layer; and a gate electrode, a source electrode and a drain electrode that are formed on the third semiconductor layer. In the semiconductor device, the second semiconductor layer includes an impurity diffusion region in which an impurity element contained in the first semiconductor layer is diffused, the impurity diffusion region being located directly beneath the gate electrode and being in contact with the first semiconductor layer, and the impurity element causes the impurity diffusion region to be a p-type impurity diffusion region.

Semiconductor device and fabrication method

A compound semiconductor device includes: a substrate; a GaN compound semiconductor multilayer structure disposed over the substrate; and a stress relief layer which is AlN-based and which is disposed between the substrate and the GaN compound semiconductor multilayer structure, wherein a surface of the stress relief layer that is in contact with the GaN compound semiconductor multilayer structure includes recesses that have a depth of 5 nm or more and that are formed at a number density of 2&#xd7;10cmor more.

A compound semiconductor device includes a substrate; an initial layer formed over the substrate; and a core layer which is formed over the initial layer and contains a Group III-V compound semiconductor. The initial layer is a layer of Group III atoms of the Group III-V compound semiconductor contained in the core layer.

Growing community of inventors

Kawasaki, Japan

Tetsuro Ishiguro