Kabushiki Kaisha Toshiba

Toshiba Electronic Devices & Storage Corporation

Hidehiko Yabuhara

Shigeyuki Takagi

Takuo Kikuchi

Yusuke Kawaguchi

Tatsuya Nishiwaki

Yasutomo Shiomi

Kazuyuki Ito

Akira Maekawa

Junji Kataoka

Koji Takaki

Takashi Hirotani

Hisashi Kameoka

According to one embodiment, a semiconductor device includes first and second electrodes, first to third semiconductor regions, a structure body, and a gate electrode. The first semiconductor region is provided on the first electrode. The second semiconductor region is provided on the first semiconductor region. The third semiconductor region is provided selectively on the second semiconductor region. The structure body includes an insulating part and a conductive part. The insulating part is arranged with the third and second semiconductor regions, and a portion of the first semiconductor region. The conductive part is provided in the insulating part. The conductive part includes a portion facing the first semiconductor region. The gate electrode faces the second semiconductor region. The second electrode is provided on the second and third semiconductor regions, and the structure body. The second electrode is electrically connected to the second and third semiconductor regions, and the conductive part.

Semiconductor device

According to one embodiment, a semiconductor device includes a semiconductor portion, a gate electrode, a source electrode, a first structure body, and a first insulating portion. The semiconductor portion includes SiC and includes first to third semiconductor regions. The first semiconductor region includes first to third partial regions. The second partial region is provided between the third partial region and the first partial region. The third semiconductor region is provided between the second partial region and the second semiconductor region. The source electrode is electrically connected to the second semiconductor region. The first insulating portion includes a first insulating region and a second insulating region. The first insulating region is provided between the first partial region and the gate electrode. The second insulating region is provided between the second semiconductor region and the first structure body. The first structure body includes at least one of polysilicon or TiN.

An active layer of a quantum cascade laser includes an active layer includes a plurality of emission regions and a plurality of injection regions. Each emission region includes an injection barrier layer, and an light-emitting quantum well layer that has at least two well layers, and that emits infrared light by undergoing an intersubband transition. Each injection region includes an extraction barrier layer, and a relaxation quantum well layer that creates an energy level for relaxing the energy of carriers from the each emission region. One of adjacent two well layers in the light-emitting quantum well layer of the each emission region on the side of the extraction barrier layer is deeper than a second well layer on the side of the injection barrier layer. The each emission region and the injection region are alternately stacked.

Quantum cascade laser

According to one embodiment of the invention, a semiconductor laser device includes a plurality of first unit stacked bodies and a plurality of second stacked bodies. The plurality of first unit stacked bodies have an emission region including a first quantum well layer and capable of emitting a first infrared light by an intersubband transition, and an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region to a downstream unit stacked body. The plurality of second unit stacked bodies have an emission region including a second quantum well layer and capable of emitting a second infrared light by an intersubband transition, and an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region of the second quantum well layer to a downstream unit stacked body. The second quantum well layer has at least one well width different from a well width of the first quantum well layer. The first unit stacked body and the second stacked body are stacked with spatial periodicity.

Semiconductor laser device

A semiconductor laser includes: a stacked body having an active layer including a quantum well layer, the active layer having a cascade structure including a first region capable of emitting infrared laser light with a wavelength of not less than 12 &#x3bc;m and not more than 18 &#x3bc;m by an intersubband optical transition of the quantum well layer and a second region capable of relaxing energy of a carrier alternately stacked, the stacked body having a ridge waveguide and being capable of emitting the infrared laser light; and a dielectric layer provided so as to sandwich both sides of at least part of side surfaces of the stacked body, a wavelength at which a transmittance of the dielectric layer decreases to 50% being 16 &#x3bc;m or more, the dielectric layer having a refractive index lower than refractive indices of all layers constituting the active layer.

Semiconductor laser

According to one embodiment, a nonvolatile memory device includes a first electrode, a second electrode, and a memory cell provided between the first electrode and the second electrode. The memory cell includes a retention unit, a resistance change unit, and an ion supply unit. The retention unit is provided on the first electrode and has an electron trap. The resistance change unit is provided on the retention unit. The ion supply unit is provided between the resistance change unit and the second electrode and includes a metal element.

Nonvolatile memory device and method for manufacturing the same

According to an embodiment, a semiconductor light emitting device is configured to emit light by energy relaxation of an electron between subbands of a plurality of quantum wells. The device includes an active layer and at least a pair of cladding layers. The active layer is provided in a stripe shape extending in a direction parallel to an emission direction of the light, and includes the plurality of quantum wells; and the active layer emits the light with a wavelength of 10 &#x3bc;m or more. Each of the cladding layers is provided both on and under the active layer respectively and have a lower refractive index than the active layer. At least one portion of the cladding layers contains a material having a different lattice constant from the active layer and has a lower optical absorption at a wavelength of the light than the other portion.

Semiconductor light emitting device and method for manufacturing same

According to one embodiment, a semiconductor light emitting device includes a first conductivity type semiconductor layer, a light emitting layer and a second conductivity type semiconductor layer. The first conductivity type layer has a superlattice structure. First semiconductor layers and second semiconductor layers are alternately provided in the superlattice structure. The first semiconductor layers include a first nitride semiconductor and the second semiconductor layers include a second nitride semiconductor having a larger lattice constant than the first nitride semiconductor. The light emitting layer has a multi-quantum well structure. Quantum well layers and barrier layers are alternately provided in the multi-quantum well structure. The quantum well layers include a third nitride semiconductor having a smaller lattice constant than the second nitride semiconductor and the barrier layers include a fourth nitride semiconductor having a smaller lattice constant than the third nitride semiconductor. At least one of the quantum well layers has lattice spacing equal to the lattice constant of the third nitride semiconductor.

Growing community of inventors

Kanagawa-ken, Japan

Hidehiko Yabuhara