Emcore Corporation

Gelcore, LLC

Lumination LLC

Velox Semiconductor Corporation

Ivan Eliashevich

Hari S Venugopalan

Bryan S Shelton

Stanton Earl Weaver, Jr

Xiang Gao

Mark Gottfried

Robert F Karlicek

Michael G Brown

Sebastien Libon

Boris Kolodin

Michael Murphy

Milan Pophristic

Richard A Stall

Prosanto K Mukerji

Shawn Gibb

Emil P Stefanov

Alex D Ceruzzi

Robert Frank Karlicek, Jr

Boris Peres

Chen-Lun Hsing Chen

Michael Sackrison

James E Nering

Steven Francis LeBoeuf

Mehmet Arik

Thomas Frederick Soules

Stephen Daley Arthur

LinLin Liu

David Mulford Shaddock

Mathew L Sommers

Srinath K Aanegola

Stephen Schwed

Chris Bohler

Stanton Weaver

Louis A Koszi

Bob Karlicek

Keng Ouyang

Michael Hsing

Shiping Guo

David Gotthold

In a method for fabricating a flip-chip light emitting diode device, epitaxial layers are deposited on a sapphire growth substrate to produce an epitaxial wafer. A plurality of light emitting diode devices are fabricated on the epitaxial wafer. The epitaxial wafer is diced to generate a device die. The device die is flip chip bonded to a mount. The flip chip bonding includes securing the device die to the mount by bonding at least one electrode of the device die to at least one bonding pad of the mount. Subsequent to the flip chip bonding, the growth substrate of the device die is removed via the application of laser light.

Laser lift-off of sapphire from a nitride flip-chip

A light emitting device (A) includes a semiconductor die (). The semiconductor die includes: an epitaxial structure () arranged on a substrate (), the epitaxial structure forming an active light generating region () between a first layer () on a first side of the active region and having a first conductivity type, and a second layer () on a second side of the active region and having a second conductivity type, the second side of the active region being opposite the first side of the active region and the second conductivity type being different that the first conductivity type; a first contact () in operative electrical communication with the active region via the first layer in the epitaxial structure, the first contact being arranged on a side of the epitaxial structure opposite the substrate; a second contact () in operative electrical communication with the active region via the second layer in the epitaxial structure, the second contact being arranged on a side of the epitaxial structure opposite the substrate; a first contact trace corresponding to the first contact and defined at a surface thereof distal from the substrate, the first trace including at least one area designated for bonding (); and, a second contact trace corresponding the second contact and defined at a surface thereof distal from the substrate, the second trace including at least one area () designated for bonding. Suitably, the first contact trace is substantially enclosed within the second contact trace.

Optimized contact design for thermosonic bonding of flip-chip devices

In a light emitting device, a light emitting chip () includes a stack of semiconductor layers () and an electrode () disposed on the stack of semiconductor layers. A support () has a generally planar surface () supporting the light emitting chip in a flip-chip fashion. An electrically conductive chip attachment material () is recessed into the generally planar surface of the support such that the attachment material does not protrude substantially above the generally planar surface of the support. The attachment material provides electrical communication between the electrode of the light emitting chip and an electrically conductive path (') of the support. Optionally, at least the stack of semiconductor layers and the electrode of the light emitting chip are also recessed into the generally planar surface of the support.

Support with recessed electrically conductive chip attachment material for flip-chip bonding a light emitting chip

In a method for fabricating a flip-chip light emitting diode device, epitaxial layers () are deposited on a growth substrate () to produce an epitaxial wafer. A plurality of light emitting diode devices are fabricated on the epitaxial wafer. The epitaxial wafer is diced to generate a device die (). The device die () is flip chip bonded to a mount (). The flip chip bonding includes securing the device die () to the mount () by bonding at least one electrode () of the device die () to at least one bonding pad () of the mount (). Subsequent to the flip chip bonding, a thickness of the growth substrate () of the device die () is reduced.

Flip chip light emitting diode devices having thinned or removed substrates

A flip chip light emitting diode die () includes a light-transmissive substrate () and a plurality of semiconductor layers () are disposed on the light-transmissive substrate (). The semiconductor layers () define a light-generating p/n junction. An electrode () is formed on the semiconductor layers () for flip-chip bonding the diode die () to an associated mount (). The electrode () includes an optically transparent layer () formed of a substantially optically transparent material adjacent to the semiconductor layers () that makes ohmic contact therewith, and a reflective layer () adjacent to the optically transparent layer () and in electrically conductive communication therewith.

Flip-chip light emitting diode with indium-tin-oxide based reflecting contacts

A light emitting semiconductor device die () includes an electrically insulating substrate (). First and second spatially separated electrodes () are disposed on the electrically insulating substrate. The first and second electrodes define an electrical current flow direction directed from the first electrode to the second electrode. A plurality of light emitting diode mesas () are disposed on the substrate between the first and second spatially separated electrodes. Electrical series interconnections () are disposed on the substrate between neighboring light emitting diode mesas. Each series interconnection carries electrical current flow between the neighboring mesas in the electrical current flow direction.

LED with series-connected monolithically integrated mesas

A light-emitting element () is disclosed. A light emitting diode (LED) includes a sapphire substrate () having front and back sides (), and a plurality of semiconductor layers () deposited on the front side () of the sapphire substrate (). The semiconductor layers () define a light-emitting structure that emits light responsive to an electrical input. A metallization stack () includes an adhesion layer () deposited on the back side () of the sapphire substrate (), and a solderable layer () connected to the adhesion layer () such that the solderable layer () is secured to the sapphire substrate () by the adhesion layer (). A support structure () is provided on which the LED is disposed. A solder bond () is arranged between the LED and the support structure (). The solder bond () secures the LED to the support structure ().

GaN LED with solderable backside metal

A light emitting diode () has a backside and a front-side with at least one n-type electrode () and at least one p-type electrode () disposed thereon defining a minimum electrodes separation (d). A bonding pad layer () includes at least one n-type bonding pad () and at least one p-type bonding pad () defining a minimum bonding pads separation (d) that is larger than the minimum electrodes separation (d). At least one fanning layer () interposed between the front-side of the light emitting diode () and the bonding pad layer () includes a plurality of electrically conductive paths passing through vias () of a dielectric layer () to provide electrical communication between the at least one n-type electrode () and the at least one n-type bonding pad () and between the at least one p-type electrode () and the at least one p-type bonding pad ().

Flip-chip light emitting diode device without sub-mount

A nitride semiconductor is grown on a silicon substrate by depositing a few mono-layers of aluminum to protect the silicon substrate from ammonia used during the growth process, and then forming a nucleation layer from aluminum nitride and a buffer structure including multiple superlattices of AlGaN semiconductors having different compositions and an intermediate layer of GaN or other Ga-rich nitride semiconductor. The resulting structure has superior crystal quality. The silicon substrate used in epitaxial growth is removed before completion of the device so as to provide superior electrical properties in devices such as high-electron mobility transistors.

Semiconductor structures for gallium nitride-based devices

In a light emitting package fabrication process, a plurality of light emitting chips () are attached on a sub-mount wafer (). The attached light emitting chips () are encapsulated. Fracture-initiating trenches () are laser cut into the sub-mount wafer () between the attached light emitting chips () using a laser. The sub-mount wafer () is fractured along the fracture initiating trenches ().

Laser separation of encapsulated submount

A lateral conduction Schottky diode includes multiple mesa regions upon which Schottky contacts are formed and which are at least separated by ohmic contacts to reduce the current path length and reduce current crowding in the Schottky contact, thereby reducing the forward resistance of a device. The multiple mesas may be isolated from one another and have sizes and shapes optimized for reducing the forward resistance. Alternatively, some of the mesas may be finger-shaped and intersect with a central mesa or a bridge mesa, and some or all of the ohmic contacts are interdigitated with the finger-shaped mesas. The dimensions of the finger-shaped mesas and the perimeter of the intersecting structure may be optimized to reduce the forward resistance. The Schottky diodes may be mounted to a submount in a flip chip arrangement that further reduces the forward voltage as well as improves power dissertation and reduces heat generation.

Lateral conduction Schottky diode with plural mesas

A method for separating individual optoelectronic devices, such as LEDs, from a wafer includes directing a laser beam having a width toward a major surface of the semiconductor wafer. The laser beam has an image with a first portion of a first energy per unit width and a second portion of a second energy per unit width less than the first energy. The laser beam image cuts into the first major surface of the semiconductor wafer to produce individual devices.

Laser separated die with tapered sidewalls for improved light extraction

A flip chip light emitting diode () includes a light-transmissive substrate () with a base semiconducting layer () disposed thereupon. A conductive mesh () is disposed on the base semiconducting layer () and is in electrically conductive contact therewith. Light-emitting micromesas () are disposed in openings () of the conductive mesh (). Each light emitting micromesa () has a topmost layer () of a second conductivity type that is opposite the first conductivity type. A first conductivity type electrode () is disposed on the base semiconducting layer () and is in electrical communication with the electrically conductive mesh (). An insulating layer () is disposed over the electrically conductive mesh (). A second conductivity type electrode layer () is disposed over the insulating layer () and the light-emitting micromesas (). the insulating layer () insulates the second conductivity type electrode layer () from the electrically conductive mesh ().

Flip chip light emitting diode with micromesas and a conductive mesh

A light-emitting package includes a substantially transparent substrate having a first surface and a second surface including a lens. The package also includes a light-emitting diode (LED) adapted to emit light having a predetermined wavelength, the LED being secured over the first surface of the substantially transparent substrate. The second surface of the substrate defines a principal light emitting surface of the package. The lens at the second surface has a grating pattern that matches the predetermined wavelength of the light emitted from the LED for controlling the emission geometry of the light emitted by the package. The grating pattern has a radial configuration including a series of circles that are concentric.

Microelectronic package having improved light extraction

A light-emitting microelectronic package includes a light-emitting diode () having a first region () of a first conductivity type, a second region () of a second conductivity type, and a light-emitting p-n junction () between the first and second regions. The light-emitting diode defines a lower contact surface () and a mesa () projecting upwardly from the lower contact surface. The first region () of a first conductivity type is disposed in the mesa () and defines a top surface of the mesa, and the second region () of a second conductivity type defines the lower contact surface that substantially surrounds the mesa (). The mesa includes at least one sidewall () extending between the top surface () of the mesa and the lower contact surface (), the at least one sidewall () having a roughened surface for optimizing light extraction from the package.

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Maplewood, NJ, United States of America

Ivan Eliashevich