Fujitsu Corporation

Yoshiaki Nakata

Yoshihiro Sugiyama

Kenichi Kawaguchi

Toshihiko Mori

Hiroji Ebe

Atsushi Takeuchi

Tomoyuki Akiyama

Mitsuru Sugawara

Yasuhiko Arakawa

Koji Otsubo

Osamu Ueda

Nami Yasuoka

Satoshi Nakamura

Kenichi Imamura

Naoto Horiguchi

Hiroyasu Yamashita

Osamu Wada

Shun-ichi Muto

Takashi Kita

A semiconductor photodetector element includes a semiconductor substrate having a first conductivity type; a columnar structure formed on a first surface of the semiconductor substrate, the columnar structure being composed of a semiconductor of the first conductivity type; a light absorption layer formed so as to surround the columnar structure; and a semiconductor layer formed so as to surround the light absorption layer.

Semiconductor photodetector element and method

A solar cell includes a semiconductor substrate of a first conductivity; a pillar-shaped structure constituted by a semiconductor of the first conductivity, the pillar-shaped structure being formed on the semiconductor substrate; a superlattice layer including a barrier layer and a quantum structure layer that are alternately deposited on a side wall of the pillar-shaped structure, the quantum structure layer being constituted by a material having a smaller energy bandgap than that of the barrier layer, the quantum structure layer including a wurtzite type crystal part and a zinc blend type crystal part that are alternately arranged along an axial direction of the pillar-shaped structure; and a semiconductor layer of a second conductivity that is formed so as to surround the superlattice layer, the second conductivity being an opposite conductivity to that of the first conductivity.

Solar cell and manufacturing method thereof

A semiconductor laser includes a semiconductor nanowire of a first conductivity type provided over a substrate, a light emitting layer provided around the semiconductor nanowire and insulated at an upper end and a lower end thereof, a cladding layer of a second conductivity type different from the first conductivity type, the cladding layer being provided at an outer periphery of the light emitting layer, a first electrode electrically coupled to an end portion of the semiconductor nanowire, a second electrode electrically coupled to an outer periphery of the cladding layer, a first reflection mirror provided at a one-end portion side of the semiconductor nanowire, and a second reflection mirror provided at the other end portion side of the semiconductor nanowire.

Semiconductor laser

The optical semiconductor device comprises an active layer including a plurality of quantum dot stackseach of which is formed of a plurality of quantum dot layersand a plurality of first layersalternately stacked, and a plurality of second barrier layersthicker than the first barrier layersstacked alternately with the quantum dot stacks. Thus, the quantum dot layers can be stacked with the generation of dislocations due to lattice mismatching between the substrate and the quantum dots suppressed. A number of quantum dot layers can be stacked with a desired light confinement coefficient ensured. The optical semiconductor device can have the characteristics easily improved.

Optical semiconductor device and method for fabricating the same

A quantum semiconductor device including quantum dots formed by S-K growth process taking place in a heteroepitaxial system wherein the relationship between the energy level of light holes and the energy level of heavy holes in the valence band is changed by optimizing the in-plane strain and the vertical strain accumulated in a quantum dot.

Quantum optical semiconductor device

A semiconductor optical device having a substrate having a surface of a first semiconductor having a first lattice constant; and a semiconductor lamination layer formed on the substrate, the semiconductor lamination layer having an active layer which contains quantum dots of a first kind made of a second semiconductor having a second lattice constant in bulk state smaller than the first lattice constant. The active layer may contain quantum dots of a second kind made of a third semiconductor having a third lattice constant in bulk state larger than the first lattice constant. The quantum dots of the first and second kinds are preferably disposed alternately along the thickness direction between the barrier layers having the first lattice constant.

Semiconductor optical device with quantum dots having internal tensile or compressive strain

A quantum semiconductor device includes intermediate layers of a first semiconductor crystal having a first lattice constant and stacked repeatedly, and a plurality of quantum dots of a second semiconductor crystal having a second lattice constant different from the first lattice constant. The quantum dots are dispersed in each of the intermediate layers and form a strained heteroepitaxial system with respect to the corresponding intermediate layer. Each of the quantum dots has a height substantially identical with a thickness of the corresponding intermediate layer.

Quantum semiconductor device including quantum dots and a fabrication process thereof

A quantum semiconductor memory device includes a quantum structure formed on a substrate, wherein the quantum structure includes a plurality of self-organized quantum dots forming a strained heteroepitaxial system with respect to the substrate and an accumulation layer formed adjacent to the self-organized quantum dots, and wherein the self-organized quantum dots are formed of a semiconductor crystal having a composition set such that quantum levels of the self-organized quantum dots are located higher than a conduction band of the accumulation layer.

Quantum semiconductor memory device including quantum dots

A wavelength-domain-multiplication memory comprises a first semiconductor layer including a first conductivity type impurity, a carrier barrier semiconductor layer formed on the first semiconductor layer, and quantum dots formed in the carrier barrier semiconductor layer.

Optical semiconductor memory device and read/write method therefor

A semiconductor integrated circuit device including: an off-substrate having a semiconductor surface with a plurality of steps each having a height of one monolayer and extending in one direction; a wiring layer formed on the semiconductor surface of the off-substrate and made of semiconductor material, the wiring layer including a plurality of conductive stripe regions and high resistance strip regions disposed in a stripe pattern, each stripe region extending in a direction parallel with the steps, and the conductive stripe regions and the high resistance stripe regions both having lattice structures identical to those of underlying surfaces; and semiconductor elements formed on the wiring layer and electrically connected to the conductive stripe regions, the semiconductor elements including semiconductor regions with lattice structures identical to those of the conductive stripe regions. Technologies of manufacturing a semiconductor element on a semiconductor substrate capable of reducing the number of fine pattern fabrication processes by photolithography or capable of dispensing with these processes.

Semiconductor integrated circuit using monolayer epitaxial growth

An optical semiconductor device includes a plurality of quantum structures in an active layer thereof, wherein each of the quantum structures is confined in at least two of the three, mutually perpendicular dimensions, and wherein at least two of the quantum structures are separated with a distance that allows tunneling of carriers therebetween.

Quantum optical semiconductor device producing output optical emission

Method for forming semiconductor integrated circuit using monolayer

On a substrate having a surface slightly tilted by an angle .alpha. within the range of from 0.5 to 10 degrees from the (110) plane in the &lt;00-1&gt; direction, a superlattice structure having a periodicity in both &lt;110&gt; and &lt;001&gt; directions is formed. Various band structures are possible by selecting an appropriate constituent material and periodicity for the superlattice structure. When current flows in a direction without periodicity, a very high mobility is obtained as a result of suppressed alloy scattering. If current is caused to flow in a direction with periodicity, and the periodicity is properly selected, optical phonon scattering can also be suppressed.

Ordered mixed crystal semiconductor superlattice device

An active layer having a predetermined effective band gap, a predetermined effective refractive index, and a predetermined thickness is sandwiched between a first clad layer and a second clad layer. Each of the clad layers has an effective band gap wider than that of the active layer, an effective refractive index lower than that of the active layer, and a predetermined thickness. On the first clad layer, there is disposed a first stack structure doped to a first conductivity type, which alternately includes a layer of a high refractive index and a layer of a low refractive index, and has a discontinuity of a band of the first conductivity type made quite smaller than that of a band of a second conduction type. On the second clad layer, there is disposed a second stack structure doped to the second conductivity type, which alternately includes a layer of a high refractive index and a layer of a low refractive index, and has a discontinuity of a band of the second conductivity type made quite smaller than that of the band of the first conductivity type. Each of the first and second stack structures serves as an optical filter and also forms a low-resistance conduction path.

Growing community of inventors

Kawasaki, Japan

Yoshiaki Nakata