Fujitsu Corporation

Junji Kotani

Norikazu Nakamura

Atsushi Yamada

Tetsuro Ishiguro

Kozo Makiyama

Shirou Ozaki

Shuichi Tomabechi

Naoya Okamoto

Toshihiro Ohki

Hisao Shigematsu

Junya Yaita

A compound semiconductor device includes a carrier supply layer, a channel layer disposed over the carrier supply layer and configured to include InGaAs, and an etching stopper layer disposed over the channel layer, and configured to include a first layer disposed over the channel layer and configured to include InGaP, and a second layer disposed over the first layer and configured to include InGaP, wherein x1 is greater than 0 and less than or equal to 1, x2 is greater than or equal to 0 and less than 1, and x1 is greater than x2.

Compound semiconductor device, amplifier, and method for manufacturing compound semiconductor device

A semiconductor device includes an underlayer made of a first nitride semiconductor, a first buffer layer made of a second nitride semiconductor, provided on the underlayer, and subjected to compressive stress from the underlayer in an in-plane direction which is perpendicular to a thickness direction of the underlayer, a second buffer layer made of a third nitride semiconductor, provided on the first buffer layer, and subjected to compressive stress from the first buffer layer in the in-plane direction, a channel layer made of a fourth nitride semiconductor, provided on the second buffer layer, and subjected to compressive stress from the second buffer layer in the in-plane direction, and a barrier layer made of a fifth nitride semiconductor, and provided above the channel layer.

Semiconductor device

A disclosed semiconductor device includes an electron transit layer; an electron supply layer disposed above the electron transit layer; a source electrode, a drain electrode, and a gate electrode, the source electrode, the drain electrode, and the gate electrode being disposed on the electron supply layer; a first capping layer disposed on the electron supply layer between the gate electrode and the drain electrode; and a negative charge generation layer disposed on the first capping layer, the negative charge generation layer being configured to generate a negative charge.

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 semiconductor device includes a substrate; a first barrier layer containing AlN, over the substrate; a channel layer containing BGaN, over the first barrier layer; and a second barrier layer containing AlN, over the channel layer. A difference between a first lattice constant of the channel layer and a second lattice constant of the first barrier layer is less than or equal to 1.55% of the second lattice constant.

Semiconductor device and method of manufacturing the same

A disclosed compound semiconductor device includes a channel layer configured to generate carriers;

A compound semiconductor device includes a substrate, a compound semiconductor layer formed over the substrate, a channel layer formed over the compound semiconductor layer, an electron supply layer formed over the channel layer, and a source electrode, a drain electrode, and a gate electrode that are formed apart from each other over the electron supply layer. A quantum well structure is formed by the compound semiconductor layer, the channel layer, and the electron supply layer.

Compound semiconductor device with quantum well structure, power supply device, and high-frequency amplifier

A compound semiconductor device includes an electron transit layer, a spacer layer disposed on the electron transit layer, and an electron supply layer disposed on the spacer layer and containing a donor impurity. The electron supply layer has a concentration distribution of the donor impurity where the donor impurity is at a first concentration at an interface between the electron supply layer and the spacer layer and at a second concentration lower than the first concentration at an upper surface of the electron supply layer, and a concentration of the donor impurity at one of arbitrarily-selected two positions closer to the upper surface in a thickness direction of the electron supply layer is less than the concentration of the donor impurity at another one of the two positions closer to the interface in the thickness direction.

Compound semiconductor device and method for manufacturing the same

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 disclosed semiconductor device includes a buffer layer formed of a compound semiconductor on a substrate, a first semiconductor layer formed of a compound semiconductor on the buffer layer, a second semiconductor layer formed of a compound semiconductor on the first semiconductor layer, a gate electrode, a source electrode, and a drain electrode formed on the second semiconductor layer, and a heat dissipation part formed below the gate electrode. In the semiconductor device, all or part of the second semiconductor layer and the first semiconductor layer is present between the gate electrode and the heat dissipation part, the heat dissipation part includes a heat dissipation layer and a first intermediate layer formed between the heat dissipation layer and both of the buffer layer and first semiconductor layer, and the heat dissipation layer is formed of a material containing carbon.

Semiconductor device and method of fabricating the semiconductor device

A semiconductor crystal substrate includes a substrate, a first semiconductor layer including a nitride semiconductor and formed over the substrate, a second semiconductor layer including a nitride semiconductor and formed over the first semiconductor layer, a first cap layer formed on the second semiconductor layer, and a second cap layer formed on the first cap layer. Each of the first semiconductor layer and the second semiconductor layer has a single-crystal structure, the first cap layer has one of a single-crystal structure and a polycrystalline structure, and the second cap layer has an amorphous structure.

Semiconductor device and method therefor including multiple cap layers with amorphous layer

A compound semiconductor device includes: a semiconductor substrate; a channel layer over the semiconductor substrate; a carrier supply layer over the channel layer; and a gate electrode, a source electrode and a drain electrode above the carrier supply layer. The semiconductor substrate includes an impurity-containing region containing an impurity, the impurity forms a level lower than a lower edge of a conduction band of silicon by 0.25 eV or more, the impurity forms the level higher than an upper edge of a valence band of silicon.

Compound semiconductor device and method of manufacturing the same

A compound semiconductor device includes: a compound semiconductor multilayer structure including a first buffer layer composed of AlN; and a second buffer layer composed of AlGaN and formed above the first buffer layer, wherein the second buffer layer contains carbon, and wherein the concentration of carbon in the second buffer layer increases with increasing distance from a lower surface of the second buffer layer toward an upper surface of the second buffer layer.

Growing community of inventors

Atsugi, Japan

Junji Kotani