Abstract: A light emitting device includes a layer of first conductivity type, a layer of second conductivity type, and a light emitting layer disposed between the layer of first conductivity type and the layer of second conductivity type. A via is formed in the layer of second conductivity type, down to the layer of first conductivity type. The vias may be formed by, for example, etching, ion implantation, diffusion, or selective growth of at least one layer of second conductivity type. A first contact electrically contacts the layer of first conductivity type through the via. A second contact electrically contacts the layer of second conductivity type. A ring that surrounds the light emitting layer and is electrically connected to the first contact electrically contacts the layer of first conductivity type.

Abstract: A sapphire growth substrate wafer has epitaxially grown over it N-type layers, an active layer, and P-type layers to form GaN LEDs. Each LED is a flip-chip with its cathode contact and anode contact formed on the same side. The wafer is then diced to separate out the LEDs. A P-type silicon submount wafer has N-type doped interconnect regions for interconnecting all the cathode contacts together after the LEDs are mounted on the submount wafer. The sapphire substrate is then removed by a laser lift-off process. A bias voltage is then applied to the cathode contacts via the interconnect regions to bias the N-type layers for a photo-electrochemical etching process that roughens the exposed layer for increased light extraction. The submount wafer is then diced, cutting through the doped interconnect regions.

Abstract: A light emitting device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A contact is formed on the semiconductor structure, the contact comprising a reflective metal in direct contact with the semiconductor structure and an additional metal or semi-metal disposed within the reflective metal. In some embodiments, the additional metal or semi-metal is a material with higher electronegativity than the reflective metal. The presence of the high electronegativity material in the contact may increase the overall electronegativity of the contact, which may reduce the forward voltage of the device. In some embodiments, an oxygen-gathering material is included in the contact.

Abstract: A semiconductor light emitting device including a light emitting layer disposed between an n-type region and a p-type region and contacts electrically connected to the n-type region and the p-type region is connected to a mount. A metal layer arbitrarily patterned to cover at least 20% of the area of the semiconductor light emitting device is plated on either a metal layer formed on the mount or a metal layer formed on one of the contacts. The plated metal layer may replace other known interconnecting techniques such as stud bumps. The semiconductor light emitting device is physically connected to the mount by causing interdiffusion between the contact surfaces of the metal layers. In some embodiments, a layer of solder is formed over the plated metal layer, and then the semiconductor light emitting device is physically connected to the mount by heating the solder.

Abstract: A light emitting device includes a first semiconductor layer of a first conductivity type, an active region, and a second semiconductor layer of a second conductivity type. First and second contacts are connected to the first and second semiconductor layers. In some embodiments at least one of the first and second contacts has a thickness greater than 3.5 microns. In some embodiments, a first heat extraction layer is connected to one of the first and second contacts. In some embodiments, one of the first and second contacts is connected to a submount by a solder interconnect having a length greater than a width. In some embodiments, an underfill is disposed between a submount and one of the first and second interconnects.

Abstract: A semiconductor light emitting device including a light emitting layer disposed between an n-type region and a p-type region and contacts electrically connected to the n-type region and the p-type region is connected to a mount. A metal layer arbitrarily patterned to cover at least 20% of the area of the semiconductor light emitting device is plated on either a metal layer formed on the mount or a metal layer formed on one of the contacts. The plated metal layer may replace other known interconnecting techniques such as stud bumps. The semiconductor light emitting device is physically connected to the mount by causing interdiffusion between the contact surfaces of the metal layers. In some embodiments, a layer of solder is formed over the plated metal layer, and then the semiconductor light emitting device is physically connected to the mount by heating the solder.

Abstract: P-type layers of a GaN based light-emitting device are optimized for formation of Ohmic contact with metal. In a first embodiment, a p-type GaN transition layer with a resistivity greater than or equal to about 7 ? cm is formed between a p-type conductivity layer and a metal contact. In a second embodiment, the p-type transition layer is any III-V semiconductor. In a third embodiment, the p-type transition layer is a superlattice. In a fourth embodiment, a single p-type layer of varying composition and varying concentration of dopant is formed.

Abstract: Described is a process for forming an LED structure using a laser lift-off process to remove the growth substrate (e.g., sapphire) after the LED die is bonded to a submount. The underside of the LED die has formed on it anode and cathode electrodes that are substantially in the same plane, where the electrodes cover at least 85% of the back surface of the LED structure. The submount has a corresponding layout of anode and cathode electrodes substantially in the same plane. The LED die electrodes and submount electrodes are ultrasonically welded together such that virtually the entire surface of the LED die is supported by the electrodes and submount. Other bonding techniques may also be used. No underfill is used. The growth substrate, forming the top of the LED structure, is then removed from the LED layers using a laser lift-off process.

Abstract: A semiconductor light emitting device including a light emitting layer disposed between an n-type region and a p-type region and contacts electrically connected to the n-type region and the p-type region is connected to a mount. A metal layer arbitrarily patterned to cover at least 20% of the area of the semiconductor light emitting device is plated on either a metal layer formed on the mount or a metal layer formed on one of the contacts. The plated metal layer may replace other known interconnecting techniques such as stud bumps. The semiconductor light emitting device is physically connected to the mount by causing interdiffusion between the contact surfaces of the metal layers. In some embodiments, a layer of solder is formed over the plated metal layer, and then the semiconductor light emitting device is physically connected to the mount by heating the solder.

Abstract: A light emitting device includes a layer of first conductivity type, a layer of second conductivity type, and a light emitting layer disposed between the layer of first conductivity type and the layer of second conductivity type. A via is formed in the layer of second conductivity type, down to the layer of first conductivity type. The vias may be formed by, for example, etching, ion implantation, diffusion, or selective growth of at least one layer of second conductivity type. A first contact electrically contacts the layer of first conductivity type through the via. A second contact electrically contacts the layer of second conductivity type. A ring that surrounds the light emitting layer and is electrically connected to the first contact electrically contacts the layer of first conductivity type.

Abstract: A light emitting device includes a layer of first conductivity type, a layer of second conductivity type, and a light emitting layer disposed between the layer of first conductivity type and the layer of second conductivity type. A via is formed in the layer of second conductivity type, down to the layer of first conductivity type. The vias may be formed by, for example, etching, ion implantation, diffusion, or selective growth of at least one layer of second conductivity type. A first contact electrically contacts the layer of first conductivity type through the via. A second contact electrically contacts the layer of second conductivity type. A ring that surrounds the light emitting layer and is electrically connected to the first contact electrically contacts the layer of first conductivity type.

Abstract: A light emitting device includes a substrate, a textured layer overlying the substrate, at least one III-nitride layer overlying the textured layer, and a substantially planar light emitting region. Devices incorporating scattering layers may be formed by several different methods. In a first method, an epitaxial layer is deposited then etched to form the textured layer. In a second method, a photomask is deposited and patterned to create openings in the photomask. The textured layer is then preferentially deposited in the openings formed in the photomask. In a third method, the textured layer is deposited under conditions that favor three-dimensional growth, then optionally annealed.

Abstract: A lamp has LED sources that are placed about a lamp axis in an axial arrangement. The lamp includes a post with post facets where the LED sources are mounted. The lamp includes a segmented reflector for guiding light from the LED sources. The segmented reflector includes reflective segments each of which is illuminated primarily by light from one of the post facets (e.g., one of the LED sources on the post facet). The LED sources may be made up of one or more LED dies. The LED dies may include optic-on-chip lenses to direct the light from each post facet to a corresponding reflective segment. The LED dies may be of different sizes and colors chosen to generate a particular far-field pattern.

Abstract: A light emitting device includes a first semiconductor layer of a first conductivity type, an active region, and a second semiconductor layer of a second conductivity type. First and second contacts are connected to the first and second semiconductor layers. In some embodiments at least one of the first and second contacts has a thickness greater than 3.5 microns. In some embodiments, a first heat extraction layer is connected to one of the first and second contacts. In some embodiments, one of the first and second contacts is connected to a submount by a solder interconnect having a length greater than a width. In some embodiments, an underfill is disposed between a submount and one of the first and second interconnects.

Abstract: A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n>2.0 and light absorption coefficient ?, at the emission wavelength of the active region, of ?>3 cm?1. In a preferred embodiment, the substrate material has a refractive index n>2.3, and the light absorption coefficient, ?, of the substrate material is ?<1 cm?1.

Abstract: A light emitting device includes a first semiconductor layer of a first conductivity type, an active region, and a second semiconductor layer of a second conductivity type. First and second contacts are connected to the first and second semiconductor layers. In some embodiments at least one of the first and second contacts has a thickness greater than 3.5 microns. In some embodiments, a first heat extraction layer is connected to one of the first and second contacts. In some embodiments, one of the first and second contacts is connected to a submount by a solder interconnect having a length greater than a width. In some embodiments, an underfill is disposed between a submount and one of the first and second interconnects.

Abstract: The amount of usefully captured light in an optical system may be increased by concentrating light in a region where it can be collected by the optical system. A light emitting device may include a substrate and a plurality of semiconductor layers. In some embodiments, a reflective material overlies a portion of the substrate and has an opening through which light exits the device. In some embodiments, reflective material overlies a portion of a surface of the semiconductor layers and has an opening through which light exits the device. In some embodiments, a light emitting device includes a transparent member with a first surface and an exit surface. At least one light emitting diode is disposed on the first surface. The transparent member is shaped such that light emitted from the light emitting diode is directed toward the exit surface.

Abstract: Silver electrode metallization in light emitting devices is subject to electrochemical migration in the presence of moisture and an electric field. Electrochemical migration of the silver metallization to the pn junction of the device results in an alternate shunt path across the junction, which degrades efficiency of the device. In accordance with a form of this invention, a migration barrier is provided for preventing migration of metal from at least one of the electrodes onto the surface of the semiconductor layer with which the electrode is in contact.

Abstract: A light-emitting semiconductor device includes a stack of layers including an active region. The active region includes a semiconductor selected from the group consisting of III-Phosphides, III-Arsenides, and alloys thereof. A superstrate substantially transparent to light emitted by the active region is disposed on a first side of the stack. First and second electrical contacts electrically coupled to apply a voltage across the active region are disposed on a second side of the stack opposite to the first side. In some embodiments, a larger fraction of light emitted by the active region exits the stack through the first side than through the second side. Consequently, the light-emitting semiconductor device may be advantageously mounted as a flip chip to a submount, for example.

Abstract: A structure includes semiconductor light emitting device and a wavelength converting layer. The wavelength converting layer converts a portion of the light emitted from the semiconductor light emitting device. The dominant wavelength of the combined light from the semiconductor light emitting device and the wavelength converting layer is essentially the same as the wavelength of light emitted from the device. The wavelength converting layer may emit light having a spectral luminous efficacy greater than the spectral luminous efficacy of the light emitted from the device. Thus, the structure has a higher luminous efficiency than a device without a wavelength converting layer.