Abstract: A method for producing a semiconductor substrate of the present invention, includes the steps: forming a first patterned mask containing a material having a growth suppressing effect on a lower substrate; growing a semiconductor crystal on the lower substrate via the first patterned mask to form a first semiconductor crystal layer; forming a second patterned mask containing a material having a growth suppressing effect on or above the lower substrate, the second patterned mask at least having a surface which is positioned at a level different from a level of a surface of the first patterned mask, with respect to a surface of the lower substrate; and growing a semiconductor crystal on or above the lower substrate via the second patterned mask to form a second semiconductor crystal layer.

Abstract: A method for producing a semiconductor substrate includes the steps of: forming a first patterned mask containing a material having a growth suppressing effect on a substrate; growing a first nitride semiconductor on a portion of the substrate corresponding to an opening portion of the first patterned mask; forming a second patterned mask containing a material having a growth suppressing effect only on a main surface of the first nitride semiconductor which is positioned above the opening portion of the first patterned mask; and growing a semiconductor crystal substantially from the side surface of the first nitride semiconductor so as to form a second nitride semiconductor which integrally includes the first patterned mask and the second patterned mask.

Abstract: A silicon substrate is used as the substrate, on which a conical projection is formed as a cathode. A gate electrode is arranged via an insulating film formed on the substrate. The gate electrode is formed so as to enclose and encircle the cathode while the pointed portion of the cathode and the surface of the gate electrode are coated with two layered coating films.

Abstract: A method for producing a semiconductor substrate of the present invention, includes the steps: forming a first patterned mask containing a material having a growth suppressing effect on a lower substrate; growing a semiconductor crystal on the lower substrate via the first patterned mask to form a first semiconductor crystal layer; forming a second patterned mask containing a material having a growth suppressing effect on or above the lower substrate, the second patterned mask at least having a surface which is positioned at a level different from a level of a surface of the first patterned mask, with respect to a surface of the lower substrate; and growing a semiconductor crystal on or above the lower substrate via the second patterned mask to form a second semiconductor crystal layer.

Abstract: A method for producing a semiconductor substrate of the present invention, includes the steps: forming a first patterned mask containing a material having a growth suppressing effect on a lower substrate; growing a semiconductor crystal on the lower substrate via the first patterned mask to form a first semiconductor crystal layer; forming a second patterned mask containing a material having a growth suppressing effect on or above the lower substrate, the second patterned mask at least having a surface which is positioned at a level different from a level of a surface of the first patterned mask, with respect to a surface of the lower substrate; and growing a semiconductor crystal on or above the lower substrate via the second patterned mask to form a second semiconductor crystal layer.

Abstract: A method for producing a semiconductor substrate of the present invention, includes the steps: forming a first patterned mask containing a material having a growth suppressing effect on a lower substrate; growing a semiconductor crystal on the lower substrate via the first patterned mask to form a first semiconductor crystal layer; forming a second patterned mask containing a material having a growth suppressing effect on or above the lower substrate, the second patterned mask at least having a surface which is positioned at a level different from a level of a surface of the first patterned mask, with respect to a surface of the lower substrate; and growing a semiconductor crystal on or above the lower substrate via the second patterned mask to form a second semiconductor crystal layer.

Abstract: The present invention provides a dielectric thin film capacitor element in which leak current may be suppressed from increasing over time while energizing at high temperature and which has excellent insulating quality and reliability and a manufacturing method thereof. The dielectric thin film capacitor element is constructed by forming a lower electrode, a dielectric thin film and an upper electrode one after another on a substrate, wherein the dielectric thin film capacitor element is characterized in that the dielectric thin film is made of an oxide material composed of at least titanium and strontium and containing erbium.

Abstract: A cathode is formed on a glass substrate by depositing nickel thereon, and silicon dioxide is allowed to accumulate on the cathode by sputtering to form an insulator film. Then, a gate electrode is provided on the insulator film by depositing nickel thereon. A hole is formed on the glass substrate by lithography to carry out patterning, and the gate electrode and the insulator film are selectively etched to create a hole for the formation of an emitter emitting electrons. Furthermore, nickel is stacked into the hole by deposition to form the emitter, and subsequently the emitter is covered with sulfur as a high vapor-pressure substance to form a high vapor-pressure substance layer.

Abstract: There is provided a magnetron comprising a cold cathode having an electron emitting member which is formed linearly or as a plane on a substrate to emit electrons a subdivided anode disposed oppositely in parallel with the electron emitting member, the subdivided anode having cavity resonators formed therein at the side of the cold cathode, and a magnet which producing a magnetic field lying at right angles to an electric field applied between the cold cathode and the subdivided anode. There is also provided a microwave oven for dielectric-heating a substance to be heated by using the magnetron as a microwave supply source.

Abstract: A system for transmitting information with a coherent beam being propagatable in the air is arranged to include a transmitting device having a modulator and an emitting circuit and a receiving device having a generator, a mixer, a frequency discriminating circuit, and reproducing circuit. The modulator modulates a reference light frequency (wavelength) or phase of a coherent beam to be emitted from a light source according to the signal. The emitting circuit emits the modulated beam as a divergent beam having such a power density as being safe to human eyes. The generator generates a coherent locally oscillated beam. The mixer mixes the signal beam with the locally oscillated beam and photoelectric-converts the mixed beam. The frequency discriminating circuit frequency-discriminates the a.c. component of the photoelectric-converted output. The reproducing circuit reproduces a signal from the output of frequency discriminating circuit.

Abstract: A semiconductor laser device with window regions according to the present invention is provided, in which a double hetero structure including cladding layers and an active layer sandwiched by the cladding layers is formed on a semiconductor substrate, the double hetero structure is buried in burying layers with a bandgap larger than that of the active layer, and the burying layers form window regions situated at both end facets of the double hetero structure, wherein the window regions have a waveguide structure including a plurality of semiconductor layers with different bandgaps.

Abstract: A semiconductor laser device is disclosed which emits laser light from a facet. The semiconductor laser device comprises a multi-layered structure formed on a semiconductor substrate, the multi-layered structure having an AlGaAs active layer for laser oscillation, and a protective film formed on the facet, wherein a film containing sulfur is provided between the facet and the protective film.

Abstract: A semiconductor laser device is disclosed which emits laser light from a facet. The semiconductor laser device comprises a multi-layered structure formed on a semiconductor substrate, the multi-layered structure having an AlGaAs active layer for laser oscillation, and a protective film formed on the facet, wherein a film containing sulfur is provided between the facet and the protective film.

Abstract: A semiconductor laser device is disclosed which emits laser light from an end facet. The semiconductor laser device comprises a multi-layered structure formed on a semiconductor substrate, the multi-layered structure having an active layer for laser oscillation, and a pair of cleavage planes on the side of the multi-layered structure, wherein a graded-band-gap layer is formed on at least one of the cleavage planes, the graded-band-gap layer having a forbidden band gap which increases gradually with an increase in the distance from the cleavage plane, and the surface of the graded-band-gap layer constituting the end facet.

Abstract: A semiconductor laser device, includes (1) a first semiconductor layer having a mesa-shaped stripe, (2) a current blocking layer applied on the first semiconductor layer except the top of the mesa-shaped stripe of the first semiconductor layer, the current blocking layer allowing the electric current to flow only through the mountain-shaped region, (3) a first cladding layer applied on the current blocking layer and on the top of the mountain-shaped stripe of the first semiconductor layer, and having charge carriers of the same type with that of the first semiconductor layer, (4) an active layer applied on the first cladding layer, and (5) a second cladding layer applied on the active layer, and having charge carriers of the type opposite to that of the first cladding layer, wherein the first cladding layer, the active layer and the second cladding layer compose a multilayer structure of the double heterojunction type for the laser excitation.

Abstract: An optical memory semiconductor laser apparatus incorporating a recording semiconductor laser device for an optical memory and a replaying semiconductor laser device for an optical memory therein into a single body, wherein the oscillation threshold current of replaying semiconductor laser device is smaller than that of recording semiconductor laser device.

Abstract: A higher harmonic wave generator, comprising: (1) a first optical waveguide made of a nonlinear optical material, having a structure which can guide the incident fundamental wave; and (2) a second optical waveguide made of nonlinear optical material, connected to the first optical wave guide optically, having a structure which can guide a higher harmonic wave of the fundamental wave; wherein the effective refractive index of the first optical waveguide is made to be equal to the effective refractive index of the second optical waveguide.

Abstract: A semiconductor laser apparatus includes a groove of a specified length that is formed by etching an end portion of a semiconductor laser element, and a higher harmonic generating device having a waveguide of approximately the same cross-sectional dimensions as the dimensions of the resonator that is mounted in the semiconductor laser element. The higher harmonic generating device is secured by being fused in the groove with the optical axis of the waveguide coinciding with the optical axis of the resonator.

Abstract: An integrated optical disc pickup comprising an optical waveguide in the form of a insulation layer provided on the surface of a substrate, a semiconductor laser disposed outside the waveguide, a beam splitter of the transmission type and a Luneburg lens provided on the path of propagation of a laser beam from the semiconductor laser through the waveguide and arranged in the order mentioned in a direction away from the laser, a transmission grating provided on the path through the waveguide to be followed by the laser beam upon having its direction changed by the beam splitter after emanating from the laser, passing through the beam splitter and the Luneburg lens, being reflected from an optical disc disposed outside the waveguide and passing through the Luneburg lens, and first and second photodetectors disposed on the paths of propagation through the waveguide of two portions of the laser beam divided by the diffraction grating.

Abstract: A semiconductor harmonic generating device comprising a nonlinear medium and a waveguide which is provided in the upper face of the nonlinear medium. A higher harmonic laser light from a fundamental wave laser light which passes through the waveguide, wherein the waveguide has refractive index dispersion means for counterbalancing the refractive index difference caused by wavelength dispersion, occurring in the nonlinear medium, between the fundamental wave laser light and the higher harmonic laser light.