Abstract: Quantum wire is formed on the bottom of a V-shaped groove in a V-grooved substrate as a channel between source and drain electrodes or as at least part of the channel. A photocarrier accumulation region is provided within the quantum wire or at a position connected to or adjacent to the quantum wire for accumulating charges generated when light shines onto a photosensitive region that comprises at least a clad layer that covers the quantum wire. A recess is provided in the upper clad layer to localize the photocarrier accumulation region. As a result, it is possible to provide a photodetector that exhibits high sensitivity, high speed and low power consumption in an expanded wavelength region. It is also possible to provide a photodetector capable of constructing core portions thereof by one-time selective growth.

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 quantum nanostructure semiconductor laser is provided that does not use a buried structure defined by etching and regrowth processes in the prior arts, and can be manufactured using a procedure that is simple and has good reproducibility. This helps to reduce the threshold current and provides good lasing wavelength stability. The laser has a stripe-shaped ridge with a plurality of V-grooves formed on a compound semiconductor substrate in the direction of laser beam emisson, with the V-grooves being arrayed in parallel, with each V-groove extending orthogonally to the direction of laser beam emission. On the ridge, an optical waveguide is provided that comprises a lower cladding layer, a plurality of quantum wires and an upper cladding layer formed in order by a crystal growth process. 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, thereby constituting the laser active region.

Abstract: Quantum wire is formed on the bottom of a V-shaped groove in a V-grooved substrate as a channel between source and drain electrodes or as at least part of the channel. A photocarrier accumulation region is provided within the quantum wire or at a position connected to or adjacent to the quantum wire for accumulating charges generated when light shines onto a photosensitive region that comprises at least a clad layer that covers the quantum wire. A recess is provided in the upper clad layer to localize the photocarrier accumulation region. As a result, it is possible to provide a photodetector that exhibits high sensitivity, high speed and low power consumption in an expanded wavelength region. It is also possible to provide a photodetector capable of constructing core portions thereof by one-time selective growth.

Abstract: A Group III atomic layer required for fabrication of a semiconductor quantum nanostructure is grown to be properly restricted to a monolayer.A substrate is configured to have a fast-growth surface portion where growth of a Ga atomic layer proceeds at a relatively high rate and a slow-growth surface portion where the growth of the Ga atomic layer proceeds at a relatively low rate. Ga atoms are supplied to the fast-growth surface portion in an amount not less than that which grows one layer of the Group III atoms. Excess Ga atoms on the fast-growth surface portion are allowed to migrate to the slow-growth surface portion by surface migration, thereby growing only one layer of the Ga atoms on the fast-growth surface portion.

Abstract: A charged beam apparatus comprising a vacuum chamber having a moving mechanism inside and a sample chamber, the sample chamber being used placed in an ultra-high vacuum atmosphere or a gas atmosphere, wherein a flat surface is formed on that surface of the moving mechanism which faces the sample chamber, and a flange having a flat open surface is mounted between the vacuum chamber and the sample chamber such that the open surface is opposed to the flat surface with a tiny gap being formed between the open surface and the flat surface for permitting vacuum venting without imposing any restrictions on the moving mechanism, whereby the apparatus operates without restricting the action of the moving mechanism.

Abstract: A surface-emitting semiconductor laser diode has a vertical multilayer active region and a lateral buried heterojunction. Effective carrier confinement to the active region is achieved, thereby permitting laser action at room temperature under continuous-wave operation with a low threshold current of about 2 mA.

Abstract: A scanning-type lithographic and image-pickup device causes the terminal face of either a projecting optical fiber or a picking-up optical fiber to scan a given object in the plane of real image of an objective lens, projects a light through the projecting optical fiber onto the object, and receives the reflected light or a light of photoluminescence through the picking-up optical fiber. When this device is applied to a spectromicroscope, the quantitative surface information can be spectrally measured with high resolution and high reproducibility. When the device is applied to a contracting-projection exposure device or a selective laser annealing device, positional alignment and exposure pattern correction can be easily effected with high accuracy and high productivity. Simultaneous fabrication of a plurality of electronic components can be also obtained by use of this device.