Abstract: This light sensitive element comprises: a substrate; a light absorbing layer containing InGaA, the light absorbing layer being disposed on the substrates; and semiconductor layers containing InAsP. The semiconductor layers are disposed on an upper surface and on a lower surface of the light absorbing layer, respectively. The semiconductor layers constitutes a quantum well structure with the light absorbing layer.

Abstract: To provide a method and apparatus for production of a nitrogen compound film by a plasma, wherein the method and apparatus are suitable for area enlargement by a process at a higher pressure with lower power consumption, without applying a voltage to a base material, and without using a large chamber. In nitrogen compound production for producing a nitrogen compound by generating a microwave plasma, in a step of jetting a material gas containing a nitrogen-based gas onto a surface of a base material from a nozzle under flow rate control while applying a microwave to the material gas to thereby irradiate the surface of the base material with a plasma containing nitrogen-based reactive species generated from the material gas, the pressure is set higher than a pressure at which the mean free path of ions in the plasma is shorter than the Debye length.

Abstract: An imaging system includes an infrared camera 10 that is sensitive to light beams having wavelengths in an infrared region, a lighting unit 20 that emits light beams having multiple wavelengths in an infrared region in a region including the wavelengths to which the infrared camera is sensitive, and a control unit 30 that controls capture of an image by the infrared camera 10 and emission of a light beam by the lighting unit 20.

Abstract: There is provided a compound semiconductor stack including a substrate (101) of which electrical resistance is greater than or equal to 1×105 ?cm, a first compound semiconductor layer (102) which is formed on the substrate (101), and contains In and Sb doped with carbon, and a second compound semiconductor layer (103) which is formed on the first compound semiconductor layer (102), has a carbon concentration less than a carbon concentration of the first compound semiconductor layer (102), and contains In and Sb. A film thickness of the first compound semiconductor layer (102) is greater than or equal to 0.005 ?m and less than or equal to 0.2 ?m. In addition, the carbon concentration of the first compound semiconductor layer (102) is greater than or equal to 1×1015 cm?3 and less than or equal to 5×1018 cm?3.

Abstract: A hetero-junction bipolar phototransistor includes a photo-absorption layer formed of a first conductivity type semiconductor layer, and a collector operating as a barrier layer, a base layer, and an emitter layer, which are stacked in sequence on the photo-absorption layer. The photo-absorption layer, collector, base layer and emitter layer forms a first mesa structure, and an emitter contact layer forms a second mesa structure. The photo-absorption layer includes a semiconductor layer with a narrow gap corresponding to a light-sensing wavelength of the phototransistor. The collector includes a semiconductor layer with a wider gap than a gap of the photo-absorption layer. The base layer has an energy level equal to or higher than the energy level of the collector. The emitter layer has a wide gap as compared to the base layer, and an energy level in a valence band is lower than an energy level of the base layer.

Abstract: A highly-efficient semiconductor light emitting diode with improved light extraction efficiency comprising at least a substrate having a plurality of crystal planes, a first conductivity-type barrier layer, an active layer serving as a light emitting layer and a second conductivity-type barrier layer stacked on the substrate. The semiconductor light emitting diode comprises a ridge structure configured from one flat surface and at least two inclining surfaces in the in-plane direction. The width (W) of the flat surface of the ridge structure is 2? (?: light emission wavelength) or less.

Abstract: An array structure solves issues that exist in conventional compound semiconductor photodiode arrays, such as large cross talk, large surface leaks, large stray capacitance, narrow detection wavelength bands, and bad manufacturing yield, simultaneously. A photodiode array has, laminated upon a semiconductor substrate, a buffer layer (8) with a broad forbidden band width, an I-type (low concentration photosensitive layer (2) with a narrow forbidden band width, and an n-type semiconductor window layer (3) with a broad forbidden band width, wherein photodiode elements are electrically separated from adjacent elements, by doping the periphery of the p-type impurity, and the detection wavelength band is expanded, by making the n-type window layer (3) on the photosensitive layer (2) a thinner layer with crystal growth.

Abstract: A highly sensitive and wide spectra-range mesa type photodetector having the impurity diffusion along the mesa-sidewall is provided. A mesa-type hetero-bipolar phototransistor or photodiode having a photo-absorption layer formed by a first semiconductor layer of a first conductivity type, an anode layer (or base layer) formed by a second semiconductor layer of a second conductivity type which has an opposite polarity with the first conductivity type, a wide band gap emitter or window layer formed by the third semiconductor layer on the anode layer, and the wide band gap buffer layer of the first conductivity type which has a relatively wide band gap semiconductor as compared with the second semiconductor layer on the substrate, which also serves as the cathode layer. And the first semiconductor layer, the second semiconductor layer and the wide band gap emitter or window layer is selectively etched to form the mesa structure.

Abstract: This invention provides a photo-FET, in which a FET part and photodiode part are stacked, and the FET part and photodiode part are optimized independently in design and operational bias conditions. The semiconductor layer serving as a photo-absorption layer (41) is formed on the cathode semiconductor layer (10) of a photodiode part (50). An electron barrier layer (40) with a wider bandgap semiconductor than a photo-absorption layer (41), which also serves as an anode layer of a photodiode part (50), is formed on a photo-absorption layer (41). The channel layer (15) which constitutes the channel regions of the FET part is formed with a narrower bandgap semiconductor than an electron barrier layer (40) on an electron barrier layer (40). The hole barrier layer (16) with a bandgap wider than the semiconductor which constitutes a channel layer (15) is formed on a channel layer (15). The source electrode (30) and drain electrode (32) which are separated each others, are formed on a hole barrier layer (16).

Abstract: An array structure solves issues that exist in conventional compound semiconductor photodiode arrays, such as large cross talk, large surface leaks, large stray capacitance, narrow detection wavelength bands, and bad manufacturing yield, simultaneously. A photodiode array has, laminated upon a semiconductor substrate, a buffer layer (8) with a broad forbidden band width, an I-type (low concentration photosensitive layer (2) with a narrow forbidden band width, and an n-type semiconductor window layer (3) with a broad forbidden band width, wherein photodiode elements are electrically separated from adjacent elements, by doping the periphery of the p-type impurity, and the detection wavelength band is expanded, by making the n-type window layer (3) on the photosensitive layer (2) a thinner layer with crystal growth.

Abstract: A highly-efficient semiconductor light emitting diode with improved light extraction efficiency comprising at least a substrate having a plurality of crystal planes, a first conductivity-type barrier layer, an active layer serving as a light emitting layer and a second conductivity-type barrier layer stacked on the substrate. The semiconductor light emitting diode comprises a ridge structure configured from one flat surface and at least two inclining surfaces in the in-plane direction. The width (W) of the flat surface of the ridge structure is 2? (?: light emission wavelength) or less.

Abstract: The present invention provides a HPT having high sensitivity and extensive wavelength band characteristics. The collector and barrier layer (5) is formed on the photo-absorption layer (6), wherein the energy level in the conduction band is higher than that of the photo-absorption layer (6), the energy level in the valence band is almost equal to or higher than that of the photo-absorption layer (6) and is a relatively wider gap semiconductor than the photo-absorption layer. The base layer (4) formed on the collector and barrier layer (5), is a relatively narrow gap as compared with the collector and barrier layer (5), wherein the energy level in the conduction band is equal to or higher than that of the collector and barrier layer (5) in the boundary of the collector and barrier layer (5).

Abstract: A highly sensitive and wide spectra-range mesa type photodetector having the impurity diffusion along the mesa-sidewall is provided with. A mesa-type hetero-bipolar phototransistor or photodiode having a photo-absorption layer 10 (41) formed by a first semiconductor layer of a first conductivity type, an anode layer 40 (or base layer 4) formed by a second semiconductor layer of a second conductivity type which has an opposite polarity with the first conductivity type, a wide band gap emitter 3 or window layer 42 formed by the third semiconductor layer on the anode layer, and the wide band gap buffer layer 11 of the first conductivity type which has a relatively wide band gap semiconductor as compared with the second semiconductor layer on the substrate 12, which also serves as the cathode layer. And the first semiconductor layer 10, the second semiconductor layer 4 and the wide band gap emitter 3 or window layer 42 is selectively etched to form the mesa structure 7.

Abstract: This invention provides a photo-FET, in which a FET part and photodiode part are stacked, and the FET part and photodiode part are optimized independently in design and operational bias conditions. The semiconductor layer serving as a photo-absorption layer (41) is formed on the cathode semiconductor layer (10) of a photodiode part (50). An electron barrier layer (40) with a wider bandgap semiconductor than a photo-absorption layer (41), which also serves as an anode layer of a photodiode part (50), is formed on a photo-absorption layer (41). The channel layer (15) which constitutes the channel regions of the FET part is formed with a narrower bandgap semiconductor than an electron barrier layer (40) on an electron barrier layer (40). The hole barrier layer (16) with a bandgap wider than the semiconductor which constitutes a channel layer (15) is formed on a channel layer (15). The source electrode (30) and drain electrode (32) which are separated each others, are formed on a hole barrier layer (16).

Abstract: A photo-FET based on a compound semiconductor including a channel layer formed on a substrate constituting a current path between source and drain electrodes, serving as part of a photodiode and a photosensitive region. A back-gate layer that serving as a substrate-side depletion layer formation layer is disposed between the substrate and the channel layer, and applies to the channel layer a back-gate bias by photogenerated carriers upon illumination. A barrier layer is disposed on the front side of the channel layer that causes one of the photogenerated carriers to run through the channel layer and other of the photogenerated carriers to sojourn or be blocked off. A front-side depletion layer formation layer is disposed on the front side of the channel layer brings the front-side depletion layer into contact with the substrate-side depletion layer without illumination to close the current path in the channel layer, bringing the photo-FET to an off-state.

Abstract: A quantum nanostructure semiconductor laser includes a strip-shaped ridge with a plurality of V-grooves formed on a compound semiconductor substrate in the direction of laser beam emission, with the V-grooves arrayed in parallel and with each V-groove extending orthogonally to the direction of laser beam emission. On the ridge, an optical waveguide is provided that includes a lower cladding layer, a plurality of quantum wires, and an upper cladding layer. The quantum wires are formed to a finite length corresponding to the stripe width of the laser beam, and are each located at a position corresponding to a V-groove location. The optical waveguide is trapezoidal in shape. The quantum wires do not project out beyond the width of the ridge, but the ends of the wires are converged and closed off with the upper and lower cladding layers toward higher index crystalline planes.

Abstract: A photo-FET based on a compound semiconductor including a channel layer formed on a substrate constituting a current path between source and drain electrodes, serving as part of a photodiode and a photosensitive region. A back-gate layer that serving as a substrate-side depletion layer formation layer is disposed between the substrate and the channel layer, and applies to the channel layer a back-gate bias by photogenerated carriers upon illumination. A barrier layer is disposed on the front side of the channel layer that causes one of the photogenerated carriers to run through the channel layer and other of the photogenerated carriers to sojourn or be blocked off. A front-side depletion layer formation layer is disposed on the front side of the channel layer brings the front-side depletion layer into contact with the substrate-side depletion layer without illumination to close the current path in the channel layer, bringing the photo-FET to an off-state.

Abstract: On a grooved semiconductor substrate having a plurality of V-grooves individually extended in directions perpendicular to a direction Is of advance of an oscillated laser beam and mutually disposed in parallel along the direction Is of advance of the laser beam, a plurality of quantum wires (11) are formed on the V-grooves by selective growth of a Group III-V compound. The plurality of quantum wires are adapted to serve as limited-length active layer regions mutually disposed in parallel along the direction Is of advance of the laser beam with a period of an integer times of a quarter wavelength in a medium of a laser active layer and individually corresponding to stripe widths of laser. Consequently, a quantum nano-structure semiconductor laser satisfying at least one, or preferably both, of the decrease of a threshold and the stabilization of an oscillation frequency as compared with a conventional countertype can be provided.

Abstract: A negative resistance field-effect element that is a negative differential resistance field-effect element capable of achieving negative resistance at a low power supply voltage (low drain voltage) and also enabling securement of a high PVCR is formed on its InP substrate 11 having an asymmetrical V-groove whose surface on one side is a (100) plane and surface on the other side is a (011) plane with an InAlAs barrier layer (12) that has a trench (TR) one of whose opposed lateral faces is a (111) A plane and the other of which is a (331) B plane. An InGaAs quantum wire (13) that has a relatively narrow energy band gap is formed at the trench bottom surface as a high-mobility channel. An InAlAs modulation-doped layer (20) having a relatively wide energy band gap is formed on the quantum wire as a low-mobility channel.

Abstract: A negative resistance field-effect element that is a negative differential resistance field-effect element capable of achieving negative resistance at a low power supply voltage (low drain voltage) and also enabling securement of a high PVCR is formed on its InP substrate 11 having an asymmetrical V-groove whose surface on one side is a (100) plane and surface on the other side is a (011) plane with an InAlAs barrier layer (12) that has a trench (TR) one of whose opposed lateral faces is a (111) A plane and the other of which is a (331) B plane. An InGaAs quantum wire (13) that has a relatively narrow energy band gap is formed at the trench bottom surface as a high-mobility channel. An InAlAs modulation-doped layer (20) having a relatively wide energy band gap is formed on the quantum wire as a low-mobility channel.