Patent application number | Description | Published |
20090250790 | NITRIDE SEMICONDUCTOR WAFER AND METHOD OF PROCESSING NITRIDE SEMICONDUCTOR WAFER - Nitride semiconductor wafers which are produced by epitaxially grown nitride films on a foreign undersubstrate in vapor phase have strong inner stress due to misfit between the nitride and the undersubstrate material. A GaN wafer which has made by piling GaN films upon a GaAs undersubstrate in vapor phase and eliminating the GaAs undersubstrate bends upward due to the inner stress owing to the misfit of lattice constants between GaN and GaAs. Ordinary one-surface polishing having the steps of gluing a wafer with a surface on a flat disc, bringing another surface in contact with a lower turntable, pressing the disc, rotating the disc, revolving the turntable and whetting the lower surface, cannot remedy the inherent distortion. The Distortion worsens morphology of epitaxial wafers, lowers yield of via-mask exposure and invites cracks on surfaces. Nitride crystals are rigid but fragile. Chemical/mechanical polishing has been requested in vain. Current GaN wafers have roughened bottom surfaces, which induce contamination of particles and fluctuation of thickness. | 10-08-2009 |
20100279440 | NITRIDE SEMICONDUCTOR WAFER AND METHOD OF PROCESSING NITRIDE SEMICONDUCTOR WAFER - Nitride semiconductor wafers which are produced by epitaxially grown nitride films on a foreign undersubstrate in vapor phase have strong inner stress due to misfit between the nitride and the undersubstrate material. A GaN wafer which has made by piling GaN films upon a GaAs undersubstrate in vapor phase and eliminating the GaAs undersubstrate bends upward due to the inner stress owing to the misfit of lattice constants between GaN and GaAs. Ordinary one-surface polishing having the steps of gluing a wafer with a surface on a flat disc, bringing another surface in contact with a lower turntable, pressing the disc, rotating the disc, revolving the turntable and whetting the lower surface, cannot remedy the inherent distortion. The Distortion worsens morphology of epitaxial wafers, lowers yield of via-mask exposure and invites cracks on surfaces. Nitride crystals are rigid but fragile. Chemical/mechanical polishing has been requested in vain. Current GaN wafers have roughened bottom surfaces, which induce contamination of particles and fluctuation of thickness. | 11-04-2010 |
Patent application number | Description | Published |
20100020838 | LASER DIODE, OPTICAL DISK DEVICE AND OPTICAL PICKUP - A laser diode capable of performing self-pulsation operation, and capable of sufficiently reducing the coherence of laser light and stably obtaining low-noise laser light is provided. A laser diode includes: a laser chip including at least one laser stripe which extends in a resonator length direction between a first end surface and a second end surface opposed to each other, in which the laser stripe includes a gain region and a saturable absorption region in the resonator length direction, and the width of the laser stripe in the saturable absorption region is larger than the width of the laser stripe in the gain region. | 01-28-2010 |
20100027573 | METHOD OF DRIVING A LASER DIODE - An ultrashort pulse/ultra-high power laser diode with a simple structure and configuration is provided. In a method of driving a laser diode, the laser diode is driven by a pulse current which is 10 or more times higher than a threshold current value. The width of the pulse current is preferably 10 nanoseconds or less, and the value of the pulse current is specifically 0.4 amperes or over. | 02-04-2010 |
20100129942 | NONDESTRUCTIVE TESTING METHOD FOR OXIDE SEMICONDUCTOR LAYER AND METHOD FOR MAKING OXIDE SEMICONDUCTOR LAYER - A nondestructive testing method for an oxide semiconductor layer includes the steps of applying excitation light to an amorphous or polycrystalline target oxide semiconductor layer to be tested and measuring an intensity of photoluminescence in a wavelength region longer than a wavelength corresponding to a bandgap energy among light emitted from the target oxide semiconductor layer; and estimating a film property of the target oxide semiconductor layer on the basis of measurement results. | 05-27-2010 |
20100220754 | METHOD OF DRIVING LASER DIODE DEVICE AND LASER DIODE EQUIPMENT - A method of driving an ultrashort pulse and ultrahigh power laser diode device having a simple composition and a simple structure is provided. In the method of driving a laser diode device, light is injected from a light injection means into a laser diode device driven by a pulse current having a value 10 or more times as large as a value of a threshold current. | 09-02-2010 |
20100246622 | BI-SECTION SEMICONDUCTOR LASER DEVICE, METHOD FOR MANUFACTURING THE SAME, AND METHOD FOR DRIVING THE SAME - A method for manufacturing a bi-section semiconductor laser device includes the steps of (A) forming a stacked structure obtained by stacking, on a substrate in sequence, a first compound semiconductor layer of a first conductivity type, a compound semiconductor layer that constitutes a light-emitting region and a saturable absorption region, and a second compound semiconductor layer of a second conductivity type; (B) forming a belt-shaped second electrode on the second compound semiconductor layer; (C) forming a ridge structure by etching at least part of the second compound semiconductor layer using the second electrode as an etching mask; and (D) forming a resist layer for forming a separating groove in the second electrode and then forming the separating groove in the second electrode by wet etching so that the separating groove separates the second electrode into a first portion and a second portion. | 09-30-2010 |
20110164632 | METHOD OF DRIVING A LASER DIODE - An ultrashort pulse/ultra-high power laser diode with a simple structure and configuration. The laser diode can be driven by a pulse current which is 10 or more times higher than a threshold current value. The width of the pulse current is preferably 10 nanoseconds or less, and the value of the pulse current is specifically 0.4 amperes or over. | 07-07-2011 |
20110216788 | MODE-LOCKED SEMICONDUCTOR LASER DEVICE AND DRIVING METHOD THEREOF - Provided is a driving method of a mode-locked semiconductor laser device comprising a laminated structure in which a first compound semiconductor layer, a third compound semiconductor layer having an emission region and a second compound semiconductor layer are successively laminated, a second electrode, and a first electrode. The laminated structure is formed on a compound semiconductor substrate having polarity, the third compound semiconductor layer includes a quantum well structure having a well layer and a barrier layer. The well layer has a depth of 1 nm or more and 10 nm or less. The barrier layer has an impurity doping density of 2×10 | 09-08-2011 |
20120002271 | SEMICONDUCTOR OPTICAL AMPLIFIER - A semiconductor optical amplifier includes: a laminated structure sequentially including a first compound semiconductor layer composed of GaN compound semiconductor and having a first conductivity type, a third compound semiconductor layer having a light amplification region composed of GaN compound semiconductor, and a second compound semiconductor layer composed of GaN compound semiconductor and having a second conductivity type; a second electrode formed on the second compound semiconductor layer; and a first electrode electrically connected to the first compound semiconductor layer. The laminated structure has a ridge stripe structure. When widths of the ridge stripe structure in a light output end face and the ridge stripe structure in a light incident end face are respectively W | 01-05-2012 |
20120002690 | METHOD OF DRIVING A LASER DIODE - An ultrashort pulse/ultra-high power laser diode with a simple structure and configuration is provided. In a method of driving a laser diode, the laser diode is driven by a pulse current which is 10 or more times higher than a threshold current value. The width of the pulse current is preferably 10 nanoseconds or less, and the value of the pulse current is specifically 0.4 amperes or over. | 01-05-2012 |
20120002695 | METHOD OF DRIVING A LASER DIODE - An ultrashort pulse/ultra-high power laser diode with a simple structure and configuration is provided. In a method of driving a laser diode, the laser diode is driven by a pulse current which is 10 or more times higher than a threshold current value. The width of the pulse current is preferably 10 nanoseconds or less, and the value of the pulse current is specifically 0.4 amperes or over. | 01-05-2012 |
20120281726 | BI-SECTION SEMICONDUCTOR LASER DEVICE, METHOD FOR MANUFACTURING THE SAME, AND METHOD FOR DRIVING THE SAME - A method for manufacturing a bi-section semiconductor laser device includes the steps of (A) forming a stacked structure obtained by stacking, on a substrate in sequence, a first compound semiconductor layer of a first conductivity type, a compound semiconductor layer that constitutes a light-emitting region and a saturable absorption region, and a second compound semiconductor layer of a second conductivity type; (B) forming a belt-shaped second electrode on the second compound semiconductor layer; (C) forming a ridge structure by etching at least part of the second compound semiconductor layer using the second electrode as an etching mask; and (D) forming a resist layer for forming a separating groove in the second electrode and then forming the separating groove in the second electrode by wet etching so that the separating groove separates the second electrode into a first portion and a second portion. | 11-08-2012 |
20130230936 | SEMICONDUCTOR LIGHT EMITTING DEVICE, ITS MANUFACTURING METHOD, SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD - A semiconductor light emitting device made of nitride III-V compound semiconductors including an active layer made of a first nitride III-V compound semiconductor containing In and Ga, such as InGaN; an intermediate layer made of a second nitride III-V compound semiconductor containing In and Ga and different from the first nitride III-V compound semiconductor, such as InGaN; and a cap layer made of a third nitride III-V compound semiconductor containing Al and Ga, such as p-type AlGaN, which are deposited in sequential contact. | 09-05-2013 |
20140079086 | LASER DIODE, OPTICAL DISK DEVICE AND OPTICAL PICKUP - A laser diode capable of performing self-pulsation operation, and capable of sufficiently reducing the coherence of laser light and stably obtaining low-noise laser light is provided. The laser diode includes: a laser chip including at least one laser stripe which extends in a resonator length direction between a first end surface and a second end surface opposed to each other, in which the laser stripe includes a gain region and a saturable absorption region in the resonator length direction, and the width of the laser stripe in the saturable absorption region is larger than the width of the laser stripe in the gain region. | 03-20-2014 |
20140345680 | MULTI-JUNCTION SOLAR CELL, PHOTOELECTRIC CONVERSION DEVICE, AND COMPOUND-SEMICONDUCTOR-LAYER LAMINATION STRUCTURE - A multi-junction solar cell that is lattice-matched with a base, and that includes a sub-cell having a desirable band gap is provided. A plurality of sub-cells are laminated, each including first and second compound semiconductor layers. At least one predetermined sub-cell is configured of first layers and a second layer. In each of the first layers, a 1-A layer and a 1-B layer are laminated. In the second layer, a 2-A layer and a 2-B layer are laminated. A composition A of the 1-A layer and the 2-A layer is determined based on a value of a band gap of the predetermined sub-cell. A composition B of the 1-B layer and the 2-B layer is determined based on a difference between a base lattice constant of the base and a lattice constant of the composition A. Thicknesses of 1-B layer and 2-B layer are determined based on difference between base lattice constant and a lattice constant of composition B, and on thickness of the 1-A layer and thickness of 2-A layer. | 11-27-2014 |
20140345681 | MULTI-JUNCTION SOLAR CELL, COMPOUND SEMICONDUCTOR DEVICE, PHOTOELECTRIC CONVERSION DEVICE, AND COMPOUND-SEMICONDUCTOR-LAYER LAMINATION STRUCTURE - There is provided a multi-junction solar cell that reduces contact resistance of a junction portion and is capable of performing energy conversion with high efficiency. The multi-junction solar cell includes a plurality of sub-cells | 11-27-2014 |