TOSHIBA TECHNO CENTER INC. Patent applications |
Patent application number | Title | Published |
20150069434 | DISTRIBUTED BRAGG REFLECTOR FOR REFLECTING LIGHT OF MULTIPLE WAVELENGTHS FROM AN LED - A blue LED device has a transparent substrate and a reflector structure disposed on the backside of the substrate. The reflector structure includes a Distributed Bragg Reflector (DBR) structure having layers configured to reflect yellow light as well as blue light. In one example, the DBR structure includes a first portion where the thicknesses of the layers are larger, and also includes a second portion where the thicknesses of the layers are smaller. In addition to having a reflectance of more than 97.5 percent for light of a wavelength in a 440 nm-470 nm range, the overall reflector structure has a reflectance of more than 90 percent for light of a wavelength in a 500 nm-700 nm range. | 03-12-2015 |
20140213000 | GaN Based LED Having Reduced Thickness and Method for Making the Same - A device having a carrier, a light-emitting structure, and first and second electrodes is disclosed. The light-emitting structure includes an active layer sandwiched between a p-type GaN layer and an n-type GaN layer, the active layer emitting light of a predetermined wavelength in the active layer when electrons and holes from the n-type GaN layer and the p-type GaN layer, respectively, combine therein. The first and second electrodes are bonded to the surfaces of the p-type and n-type GaN layers that are not adjacent to the active layer. The n-type GaN layer has a thickness less than 1.25 μm. The carrier is bonded to the light emitting structure during the thinning of the n-type GaN layer. The thinned light-emitting structure can be transferred to a second carrier to provide a device that is analogous to conventional LEDs having contacts on the top surface of the LED. | 07-31-2014 |
20140167082 | GaN LEDs WITH IMPROVED AREA AND METHOD FOR MAKING THE SAME - Enlightening device and method for making the same are disclosed. Individual light emitting devices such as LEDs are separated to form individual dies by process in which a first narrow trench cuts the light emitting portion of the device and a second trench cuts the substrate to which the light emitting portion is attached. The first trench can be less than 10 μm. Hence, a semiconductor area that would normally be devoted to dicing streets on the wafer is substantially reduced thereby increasing the yield of devices. The devices generated by this method can also include base members that are electrically conducting as well as heat conducting in which the base member is directly bonded to the light emitting layers thereby providing improved heat conduction. | 06-19-2014 |
20140151728 | LED WITH IMPROVED INJECTION EFFICIENCY - A light emitting device and method for making the same is disclosed. The light-emitting device includes an active layer sandwiched between a p-type semiconductor layer and an n-type semiconductor layer. The active layer emits light when holes from the p-type semiconductor layer combine with electrons from the n-type semiconductor layer therein. The active layer includes a number of sub-layers and has a plurality of pits in which the side surfaces of a plurality of the sub-layers are in contact with the p-type semiconductor material such that holes from the p-type semiconductor material are injected into those sub-layers through the exposed side surfaces without passing through another sub-layer. The pits can be formed by utilizing dislocations in the n-type semiconductor layer and etching the active layer using an etching atmosphere in the same chamber used to deposit the semiconductor layers without removing the partially fabricated device. | 06-05-2014 |
20140134775 | LIGHT EMITTING DEVICES HAVING DISLOCATION DENSITY MAINTAINING BUFFER LAYERS - A method for forming a light emitting device comprises forming a buffer layer having a plurality of layers comprising a substrate, an aluminum gallium nitride layer adjacent to the substrate, and a gallium nitride layer adjacent to the aluminum gallium nitride layer. During the formation of each of the plurality of layers, one or more process parameters are selected such that an individual layer of the plurality of layers is strained. | 05-15-2014 |
20140134765 | LED ON SILICON SUBSTRATE USING ZINC-SULFIDE AS BUFFER LAYER - A vertical GaN-based blue LED has an n-type GaN layer that was grown over a ZnS layer that in turn was grown directly on a silicon substrate. In one example, the ZnS layer is a transitional buffer layer that is 50 nm thick, and the n-type GaN layer is at least 2000 nm thick. Growing the n-type GaN layer on the ZnS buffer layer reduces lattice defect density in the n-type layer. The ZnS buffer layer provides a good lattice constant match with the silicon substrate and provides a compound polar template for subsequent GaN growth. After the epitaxial layers of the LED are formed, a conductive carrier is wafer bonded to the structure. The silicon substrate and the ZnS buffer layer are then removed. Electrodes are added and the structure is singulated to form finished LED devices. | 05-15-2014 |
20140131734 | P-TYPE DOPING LAYERS FOR USE WITH LIGHT EMITTING DEVICES - A light emitting diode (LED) comprises an n-type Group III-V semiconductor layer, an active layer adjacent to the n-type Group III-V semiconductor layer, and a p-type Group III-V semiconductor layer adjacent to the active layer. The active layer includes one or more V-pits. A portion of the p-type Group III-V semiconductor layer is in the V-pits. A p-type dopant injection layer provided during the formation of the p-type Group III-V layer aids in providing a predetermined concentration, distribution and/or uniformity of the p-type dopant in the V-pits. | 05-15-2014 |
20140131658 | LED THAT HAS BOUNDING SILICON-DOPED REGIONS ON EITHER SIDE OF A STRAIN RELEASE LAYER - A strain release layer adjoining the active layer in a blue LED is bounded on the bottom by a first relatively-highly silicon-doped region and is also bounded on the top by a second relatively-highly silicon-doped region. The second relatively-highly silicon-doped region is a sublayer of the active layer of the LED. The first relatively-highly silicon-doped region is a sublayer of the N-type layer of the LED. The first relatively-highly silicon-doped region is also separated from the remainder of the N-type layer by an intervening sublayer that is only lightly doped with silicon. The silicon doping profile promotes current spreading and high output power (lumens/watt). The LED has a low reverse leakage current and a high ESD breakdown voltage. The strain release layer has a concentration of indium that is between 5×10 | 05-15-2014 |
20140127841 | LIGHT EMITTING DEVICES HAVING LIGHT COUPLING LAYERS WITH RECESSED ELECTRODES - A light emitting device comprises a first layer of an n-type semiconductor material, a second layer of a p-type semiconductor material, and an active layer between the first layer and the second layer. A light coupling structure is disposed adjacent to one of the first layer and the second layer. In some cases, the light coupling structure is disposed adjacent to the first layer. An orifice formed in the light coupling structure extends to the first layer. An electrode formed in the orifice is in electrical communication with the first layer. | 05-08-2014 |
20140117404 | LIGHT-EMITTING DEVICE WITH IMPROVED ELECTRODE STRUCTURES - A light-emitting device includes first and second semiconductor layers and a light-emitting layer between the first and second semiconductor layers. The light-emitting device also includes an improved electrode structures. | 05-01-2014 |
20140106493 | P-TYPE DOPING LAYERS FOR USE WITH LIGHT EMITTING DEVICES - A light emitting diode (LED) comprises an n-type Group III-V semiconductor layer, an active layer adjacent to the n-type Group III-V semiconductor layer, and a p-type Group III-V semiconductor layer adjacent to the active layer. The active layer includes one or more V-pits. A portion of the p-type Group III-V semiconductor layer is in the V-pits. A p-type dopant injection layer provided during the formation of the p-type Group III-V layer aids in providing a predetermined concentration, distribution and/or uniformity of the p-type dopant in the V-pits. | 04-17-2014 |
20140080234 | LIGHT EMITTING DIODES WITH SMOOTH SURFACE FOR REFLECTIVE ELECTRODE - A light emitting diode comprising an epitaxial layer structure, a first electrode, and a second electrode. The first and second electrodes are separately disposed on the epitaxial layer structure, and the epitaxial layer structure has a root-means-square (RMS) roughness less than about 3 at a surface whereon the first electrode is formed. | 03-20-2014 |
20140054640 | DISTRIBUTED CURRENT BLOCKING STRUCTURES FOR LIGHT EMITTING DIODES - An LED device includes a strip-shaped electrode, a strip-shaped current blocking structure and a plurality of distributed current blocking structures. The current blocking structures are formed of an insulating material such as silicon dioxide. The strip-shaped current blocking structure is located directly underneath the strip-shaped electrode. The plurality of current blocking structures may be disc shaped portions disposed in rows adjacent the strip-shaped current blocking structure. Distribution of the current blocking structures is such that current is prevented from concentrating in regions immediately adjacent the electrode, thereby facilitating uniform current flow into the active layer and facilitating uniform light generation in areas not underneath the electrode. In another aspect, current blocking structures are created by damaging regions of a p-GaN layer to form resistive regions. In yet another aspect, current blocking structures are created by etching away highly doped contact regions to form regions of resistive contact between conductive layers. | 02-27-2014 |
20140054638 | LIGHT EMITTING DEVICES HAVING SHIELDED SILICON SUBSTRATES - Light emitting devices comprise a light emitting component, such as a GaN LED having active material layers supported by a Silicon substrate, which can be a growth substrate, or attached. Phosphor(s) can be disposed relative to the light emitting component to absorb a primary emission, and produce a secondary emission that can be relatively tuned or selected so that their combination produces light of a desired spectrum, such as light appearing white. The Silicon substrate has exposed sidewalls, which can be angled, with respect to planar surfaces of the substrate, and a light reflecting material, such as a diffusely reflective material coats the sidewalls. The reflective material can be opaque to the primary and secondary emissions. If other exposed portions of the Silicon substrate exist and are exposed to primary or secondary light, these other exposed portions can be coated with such light reflecting material. | 02-27-2014 |
20130328093 | THIN-FILM LED WITH P AND N CONTACTS ELECTRICALLY ISOLATED FROM THE SUBSTRATE - A thin-film light emitting diode includes an insulating substrate, a reflective metal electrode on the insulating substrate forming a current spreading layer, and an epitaxial structure on the electrode. | 12-12-2013 |
20130316483 | LED with Improved Injection Efficiency - A light emitting device and method for making the same is disclosed. The light-emitting device includes an active layer sandwiched between a p-type semiconductor layer and an n-type semiconductor layer. The active layer emits light when holes from the p-type semiconductor layer combine with electrons from the n-type semiconductor layer therein. The active layer includes a number of sub-layers and has a plurality of pits in which the side surfaces of a plurality of the sub-layers are in contact with the p-type semiconductor material such that holes from the p-type semiconductor material are injected into those sub-layers through the exposed side surfaces without passing through another sub-layer. The pits can be formed by utilizing dislocations in the n-type semiconductor layer and etching the active layer using an etching atmosphere in the same chamber used to deposit the semiconductor layers without removing the partially fabricated device. | 11-28-2013 |
20130313519 | Series Connected Segmented LED - A light source and method for making the same are disclosed. The light source includes a conducting substrate, and a light emitting structure that is divided into segments. The light emitting structure includes a first layer of semiconductor material of a first conductivity type deposited on the substrate, an active layer overlying the first layer, and a second layer of semiconductor material of an opposite conductivity type from the first conductivity type overlying the active layer. A barrier divides the light emitting structure into first and second segments that are electrically isolated from one another. A serial connection electrode connects the first layer in the first segment to the second layer in the second segment. A power contact is electrically connected to the second layer in the first segment, and a second power contact electrically connected to the first layer in the second segment. | 11-28-2013 |