Patent application number | Description | Published |
20080237619 | LED with Porous Diffusing Reflector - In one embodiment, an AlInGaP LED includes a bottom n-type layer, an active layer, a top p-type layer, and a thick n-type GaP layer over the top p-type layer. The thick n-type GaP layer is then subjected to an electrochemical etch process that causes the n-type GaP layer to become porous and light-diffusing. Electrical contact is made to the p-GaP layer under the porous n-GaP layer by providing metal-filled vias through the porous layer, or electrical contact is made through non-porous regions of the GaP layer between porous regions. The LED chip may be mounted on a submount with the porous n-GaP layer facing the submount surface. The pores and metal layer reflect and diffuse the light, which greatly increases the light output of the LED. Other embodiments of the LED structure are described. | 10-02-2008 |
20080259980 | Semiconductor Light Emitting Device Including Oxide Layer - A device includes a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure is grown over an oxide layer disposed between first and second III-nitride layers. The oxide layer may at least partially relieve the strain in the light emitting layer by increasing the in-plane lattice constant of the template on which the light emitting layer is grown. The oxide layer may be formed by growing an AlInN layer in the device, etching a trench to expose the AlInN layer, then oxidizing the AlInN layer. | 10-23-2008 |
20080265263 | Polarized Semiconductor Light Emitting Device - A light emitting device includes a light emitting diode (LED), a concentrator element, such as a compound parabolic concentrator, and a wavelength converting material, such as a phosphor. The concentrator element receives light from the LED and emits the light from an exit surface, which is smaller than the entrance surface. The wavelength converting material is, e.g., disposed over the exit surface. The radiance of the light emitting diode is preserved or increased despite the isotropic re-emitted light by the wavelength converting material. In one embodiment, the polarized light from a polarized LED is provided to a polarized optical system, such as a microdisplay. In another embodiment, the orthogonally polarized light from two polarized LEDs is combined, e.g., via a polarizing beamsplitter, and is provided to non-polarized optical system, such as a microdisplay. If desired, a concentrator element may be disposed between the beamsplitter and the microdisplay. | 10-30-2008 |
20080303039 | Mount for a Semiconductor Light Emitting Device - A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer. | 12-11-2008 |
20080315228 | LOW PROFILE SIDE EMITTING LED WITH WINDOW LAYER AND PHOSPHOR LAYER - Low profile, side-emitting LEDs are described that generate white light, where all light is emitted within a relatively narrow angle generally parallel to the surface of the light-generating active layer. The LEDs enable the creation of very thin backlights for backlighting an LCD. In one embodiment, the LED emits blue light and is a flip chip with the n and p electrodes on the same side of the LED. Separately from the LED, a transparent wafer has deposited on it a red and green phosphor layer. The phosphor color temperature emission is tested, and the color temperatures vs. positions along the wafer are mapped. A reflector is formed over the transparent wafer. The transparent wafer is singulated, and the phosphor/window dice are matched with the blue LEDs to achieve a target white light color temperature. The phosphor/window is then affixed to the LED. | 12-25-2008 |
20090045427 | Photonic Crystal Light Emitting Device - A photonic crystal structure is formed in an n-type region of a III-nitride semiconductor structure including an active region sandwiched between an n-type region and a p-type region. A reflector is formed on a surface of the p-type region opposite the active region. In some embodiments, the growth substrate on which the n-type region, active region, and p-type region are grown is removed, in order to facilitate forming the photonic crystal in an n-type region of the device, and to facilitate forming the reflector on a surface of the p-type region underlying the photonic crystal. The photonic crystal and reflector form a resonant cavity, which may allow control of light emitted by the active region. | 02-19-2009 |
20090155943 | Luminescent Ceramic Element For A Light Emitting Device - A semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region is attached to a compound substrate including a host which provides mechanical support to the device and a ceramic layer including a luminescent material. In some embodiments the compound substrate includes a crystalline seed layer on which the semiconductor structure is grown. The ceramic layer is disposed between the seed layer and the host. In some embodiments, the compound substrate is attached to the semiconductor structure after growth of the structure on a conventional growth substrate. In some embodiments, the compound substrate is spaced apart from the semiconductor structure and does not provide mechanical support to the structure. In some embodiments, the ceramic layer has a thickness less than 500 μm. | 06-18-2009 |
20090173956 | CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - An AlGaInP light emitting device is formed as a thin, flip chip device. The device includes a semiconductor structure comprising an AlGaInP light emitting layer disposed between an n-type region and a p-type region. N- and p-contacts electrically connected to the n- and p-type regions are both formed on the same side of the semiconductor structure. The semiconductor structure is connected to the mount via the contacts. The growth substrate is removed from the semiconductor structure and the thick transparent substrate is omitted, such that the total thickness of semiconductor layers in the device is less than 15 μm in some embodiments, less than 10 μm in some embodiments. The top side of the semiconductor structure may be textured. | 07-09-2009 |
20100032793 | METHODS FOR RELAXATION AND TRANSFER OF STRAINED LAYERS AND STRUCTURES FABRICATED THEREBY - The present invention provides methods for forming at least partially relaxed strained material layers on a target substrate. The methods include forming islands of the strained material layer on an intermediate substrate, at least partially relaxing the strained material islands by a first heat treatment, and transferring the at least partially relaxed strained material islands to the target substrate. The at least partial relaxation is facilitated by the presence of low-viscosity or compliant layers adjacent to the strained material layer. The invention also provides semiconductor structures having an at least partially relaxed strained material layer, and semiconductor devices fabricated using an at least partially relaxed strained material layer. | 02-11-2010 |
20100041170 | Package-Integrated Thin Film LED - LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. For each die, the n and p layers are electrically bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and conductors leading to solderable package connections. The growth substrate is then removed. Because the delicate LED layers were bonded to the package substrate while attached to the growth substrate, no intermediate support substrate for the LED layers is needed. The relatively thick LED epitaxial layer that was adjacent the removed growth substrate is then thinned and its top surface processed to incorporate light extraction features. There is very little absorption of light by the thinned epitaxial layer, there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support substrate therebetween, and there is little electrical resistance between the package and the LED layers so efficiency (light output vs. power input) is high. The light extraction features of the LED layer further improves efficiency. | 02-18-2010 |
20100051974 | Light Source Including a Wavelength-Converted Semiconductor Light Emitting Device and a Filter - A semiconductor light emitting device comprises a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer is adapted to emit first light having a first peak wavelength. A first wavelength converting material is adapted to absorb the first light and emit second light having a second peak wavelength. A second wavelength converting material is adapted to absorb either the first light or the second light and emit third light having a third peak wavelength. A filter is adapted to reflect fourth light having a fourth peak wavelength. The fourth light is either a portion of the second light or a portion of the third light. The filter is configured to transmit light having a peak wavelength longer or shorter than the fourth peak wavelength. The filter is disposed over the light emitting device in the path of at least a portion of the first, second, and third light. | 03-04-2010 |
20100072489 | SEMICONDUCTOR LIGHT EMITTING DEVICES GROWN ON COMPOSITE SUBSTRATES - A plurality of III-nitride semiconductor structures, each comprising a light emitting layer disposed between an n-type region and a p-type region, are grown on a composite substrate. The composite substrate includes a plurality of islands of III-nitride material connected to a host by a bonding layer. The plurality of III-nitride semiconductor structures are grown on the III-nitride islands. The composite substrate may be formed such that each island of III-nitride material is at least partially relaxed. As a result, the light emitting layer of each semiconductor structure has an a-lattice constant greater than 3.19 angstroms. | 03-25-2010 |
20100109030 | SERIES CONNECTED FLIP CHIP LEDS WITH GROWTH SUBSTRATE REMOVED - LED layers are grown over a sapphire substrate. Individual flip chip LEDs are formed by trenching or masked ion implantation. Modules containing a plurality of LEDs are diced and mounted on a submount wafer. A submount metal pattern or a metal pattern formed on the LEDs connects the LEDs in a module in series. The growth substrate is then removed, such as by laser lift-off. A semi-insulating layer is formed, prior to or after mounting, that mechanically connects the LEDs together. The semi-insulating layer may be formed by ion implantation of a layer between the substrate and the LED layers. PEC etching of the semi-insulating layer, exposed after substrate removal, may be performed by biasing the semi-insulating layer. The submount is then diced to create LED modules containing series-connected LEDs. | 05-06-2010 |
20100176490 | METHODS OF FORMING RELAXED LAYERS OF SEMICONDUCTOR MATERIALS, SEMICONDUCTOR STRUCTURES, DEVICES AND ENGINEERED SUBSTRATES INCLUDING SAME - Methods of fabricating relaxed layers of semiconductor materials include forming structures of a semiconductor material overlying a layer of a compliant material, and subsequently altering a viscosity of the compliant material to reduce strain within the semiconductor material. The compliant material may be reflowed during deposition of a second layer of semiconductor material. The compliant material may be selected so that, as the second layer of semiconductor material is deposited, a viscosity of the compliant material is altered imparting relaxation of the structures. In some embodiments, the layer of semiconductor material may comprise a III-V type semiconductor material, such as, for example, indium gallium nitride. Methods of fabricating semiconductor structures and devices are also disclosed. Novel intermediate structures are formed during such methods. Engineered substrates include a plurality of structures comprising a semiconductor material disposed on a layer of material exhibiting a changeable viscosity. | 07-15-2010 |
20100224902 | COMPLIANT BONDING STRUCTURES FOR SEMICONDUCTOR DEVICES - A compliant bonding structure is disposed between a semiconductor light emitting device and a mount. When the semiconductor light emitting device is attached to the mount, for example by providing pressure, heat, and/or ultrasonic energy to the semiconductor light emitting device, the compliant bonding structure collapses to partially fill a space between the semiconductor light emitting device and the mount. In some embodiments, the compliant bonding structure is plurality of metal bumps that undergo plastic deformation during bonding. In some embodiments, the compliant bonding structure is a porous metal layer. | 09-09-2010 |
20100264454 | SEMICONDUCTOR LIGHT EMITTING DEVICE GROWING ACTIVE LAYER ON TEXTURED SURFACE - In accordance with embodiments of the invention, at least partial strain relief in a light emitting layer of a III-nitride light emitting device is provided by configuring the surface on which at least one layer of the device grows such that the layer expands laterally and thus at least partially relaxes. This layer is referred to as the strain-relieved layer. In some embodiments, the light emitting layer itself is the strain-relieved layer, meaning that the light emitting layer is grown on a surface that allows the light emitting layer to expand laterally to relieve strain. In some embodiments, a layer grown before the light emitting layer is the strain-relieved layer. In a first group of embodiments, the strain-relieved layer is grown on a textured surface. | 10-21-2010 |
20100289044 | WAVELENGTH CONVERSION FOR PRODUCING WHITE LIGHT FROM HIGH POWER BLUE LED - A white light LED is described that uses an LED die that emits visible blue light in a wavelength range of about 450-470 nm. A red phosphor or quantum dot material converts some of the blue light to a visible red light having a peak wavelength between about 605-625 nm with a full-width-half-maximum (FWHM) less than 80 nm. A green phosphor or quantum dot material converts some of the blue light to a green light having a FWHM greater than 40 nm, wherein the combination of the blue light, red light, and green light produces a white light providing a color rendering of R | 11-18-2010 |
20100295090 | MOUNT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer. | 11-25-2010 |
20110012147 | WAVELENGTH-CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE INCLUDING A FILTER AND A SCATTERING STRUCTURE - A semiconductor structure comprises a light emitting layer disposed between an n-type region and a p-type region. A wavelength converting material is disposed over the semiconductor structure. The wavelength converting material is configured to absorb light emitted by the semiconductor structure and emit light of a different wavelength. A filter configured to reflect blue ambient light is disposed over the wavelength converting material. A scattering structure is disposed over the wavelength converting layer. The scattering structure is configured to scatter light. In some embodiments, the scattering structure is a transparent material having a rough surface, containing non-wavelength-converting particles that appear substantially white in ambient light, or including both a rough surface and white particles. | 01-20-2011 |
20110084293 | MULTI-GRAIN LUMINESCENT CERAMICS FOR LIGHT EMITTING DEVICES - A ceramic body is disposed in a path of light emitted by a light source. The light source may include a semiconductor structure comprising a light emitting region disposed between an n-type region and a p-type region. The ceramic body includes a plurality of first grains configured to absorb light emitted by the light source and emit light of a different wavelength, and a plurality of second grains. For example, the first grains may be grains of luminescent material and the second grains may be grains of a luminescent material host matrix without activating dopant. | 04-14-2011 |
20110097833 | LIGHT SOURCE INCLUDING A WAVELENGHT-CONVERETED SEMICONDUCTOR LIGHT EMITTING DEVICE AND A FILTER - A semiconductor light emitting device comprises a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer is adapted to emit first light having a first peak wavelength. A first wavelength converting material is adapted to absorb the first light and emit second light having a second peak wavelength. A second wavelength converting material is adapted to absorb either the first light or the second light and emit third light having a third peak wavelength. A filter is adapted to reflect fourth light having a fourth peak wavelength. The fourth light is either a portion of the second light or a portion of the third light. The filter is configured to transmit light having a peak wavelength longer or shorter than the fourth peak wavelength. The filter is disposed over the light emitting device in the path of at least a portion of the first, second, and third light. | 04-28-2011 |
20110114987 | COMPLIANT BONDING STRUCTURES FOR SEMICONDUCTOR DEVICES - 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 metal p-contact disposed on the p-type region, and a metal n-contact disposed on the n-type region. The metal p-contact and the metal n-contact are both formed on the same side of the semiconductor structure. The light emitting device is connected to a mount by a bonding structure. The bonding structure includes a plurality of metal regions separated by gaps and a metal structure disposed between the light emitting device and the mount proximate to an edge of the light emitting device. The metal structure is configured such that during bonding, the metal structure forms a continuous seal between the light emitting device and the mount. | 05-19-2011 |
20110156056 | WAVELENGTH-CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE - A material such as a phosphor is optically coupled to a semiconductor structure including a light emitting region disposed between an n-type region and a p-type region, in order to efficiently extract light from the light emitting region into the phosphor. The phosphor may be phosphor grains in direct contact with a surface of the semiconductor structure, or a ceramic phosphor bonded to the semiconductor structure, or to a thin nucleation structure on which the semiconductor structure may be grown. The phosphor is preferably highly absorbent and highly efficient. When the semiconductor structure emits light into such a highly efficient, highly absorbent phosphor, the phosphor may efficiently extract light from the structure, reducing the optical losses present in prior art devices. | 06-30-2011 |
20110175112 | III-V LIGHT EMITTING DEVICE INCLUDING A LIGHT EXTRACTING STRUCTURE - Embodiments of the invention include a substrate comprising a host and a seed layer bonded to the host, and a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region grown over the seed layer. A variation in index of refraction in a direction perpendicular to a growth direction of the semiconductor structure is disposed between the host and the light emitting layer. | 07-21-2011 |
20110177631 | METHOD OF FORMING A COMPOSITE SUBSTRATE AND GROWING A III-V LIGHT EMITTING DEVICE OVER THE COMPOSITE SUBSTRATE - A method according to embodiments of the invention includes providing a substrate comprising a host and a seed layer bonded to the host. The seed layer comprises a plurality of regions. A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is grown on the substrate. A top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than each of the plurality of seed layer regions. | 07-21-2011 |
20110180911 | METHODS FOR RELAXATION AND TRANSFER OF STRAINED LAYERS AND STRUCTURES FABRICATED THEREBY - The present invention provides methods for forming at least partially relaxed strained material layers on a target substrate. The methods include forming islands of the strained material layer on an intermediate substrate, at least partially relaxing the strained material islands by a first heat treatment, and transferring the at least partially relaxed strained material islands to the target substrate. The at least partial relaxation is facilitated by the presence of low-viscosity or compliant layers adjacent to the strained material layer. The invention also provides semiconductor structures having an at least partially relaxed strained material layer, and semiconductor devices fabricated using an at least partially relaxed strained material layer. | 07-28-2011 |
20120025231 | SERIES CONNECTED FLIP CHIP LEDS WITH GROWTH SUBSTRATE REMOVED - LED layers are grown over a sapphire substrate. Individual flip chip LEDs are formed by trenching or masked ion implantation. Modules containing a plurality of LEDs are diced and mounted on a submount wafer. A submount metal pattern or a metal pattern formed on the LEDs connects the LEDs in a module in series. The growth substrate is then removed, such as by laser lift-off. A semi-insulating layer is formed, prior to or after mounting, that mechanically connects the LEDs together. The semi-insulating layer may be formed by ion implantation of a layer between the substrate and the LED layers. PEC etching of the semi-insulating layer, exposed after substrate removal, may be performed by biasing the semi-insulating layer. The submount is then diced to create LED modules containing series-connected LEDs. | 02-02-2012 |
20120043552 | System and Method for Selected Pump LEDs with Multiple Phosphors - An LED pump light with multiple phosphors is described. LEDs emitting radiation at violet and/or ultraviolet wavelengths are used to pump phosphor materials that emit other colors. The LEDs operating in different wavelength ranges are arranged to reduce light re-absorption and improve light output efficiency. | 02-23-2012 |
20120074448 | LIGHT EMITTING DEVICE INCLUDING A PHOTONIC CRYSTAL AND A LUMINESCENT CERAMIC - A semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region and a photonic crystal formed within or on a surface of the semiconductor structure is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. | 03-29-2012 |
20120187372 | CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - An AlGaInP light emitting device is formed as a thin, flip chip device. The device includes a semiconductor structure comprising an AlGaInP light emitting layer disposed between an n-type region and a p-type region. N- and p-contacts electrically connected to the n- and p-type regions are both formed on the same side of the semiconductor structure. The semiconductor structure is connected to the mount via the contacts. The growth substrate is removed from the semiconductor structure and the thick transparent substrate is omitted, such that the total thickness of semiconductor layers in the device is less than 15 μm in some embodiments, less than 10 μm in some embodiments. The top side of the semiconductor structure may be textured. | 07-26-2012 |
20120214291 | RELAXATION OF STRAINED LAYERS - A method for relaxing a layer of a strained material. The method includes depositing a first low-viscosity layer on a first face of a strained material layer; bonding a first substrate to the first low-viscosity layer to form a first composite structure; subjecting the composite structure to heat treatment sufficient to cause reflow of the first low-viscosity layer so as to at least partly relax the strained material layer; and applying a mechanical pressure to a second face of the strained material layer wherein the second face is opposite to the first face and with the mechanical pressure applied perpendicularly to the strained material layer during at least part of the heat treatment to relax the strained material. | 08-23-2012 |
20120241798 | III-V LIGHT EMITTING DEVICE INCLUDING A LIGHT EXTRACTING STRUCTURE - Embodiments of the invention include a substrate comprising a host and a seed layer bonded to the host, and a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region grown over the seed layer. A variation in index of refraction in a direction perpendicular to a growth direction of the semiconductor structure is disposed between the host and the light emitting layer. | 09-27-2012 |