Velox Semiconductor Corporation

Emcore Corporation

Gelcore, LLC

Lumination LLC

Power Integrations, Inc.

Bryan S Shelton

Ivan Eliashevich

Michael Murphy

Milan Pophristic

LinLin Liu

Richard A Stall

Hari S Venugopalan

Alex D Ceruzzi

Xiang Gao

Mark Gottfried

Boris Peres

Marek Pabisz

Sebastien Libon

TingGang Zhu

Steven Francis LeBoeuf

Stanton Earl Weaver, Jr

Thomas Frederick Soules

Stephen Daley Arthur

Daniel R McGlynn

Emil P Stefanov

Stephen Schwed

Chen-Lun Hsing Chen

Michael Sackrison

Ting Gang Zhu

Chris Bohler

Shiping Guo

David Gotthold

Linlin c/o Velox Semiconductor Corp Liu

Milan c/o Velox Semiconductor Corp Pophristic

Ting Gang c/o Velox Semiconductor Corp Zhu

A gallium nitride based semiconductor Schottky diode fabricated from a n+ doped GaN layer having a thickness between one and six microns disposed on a sapphire substrate; an n&#x2212; doped GaN layer having a thickness greater than one micron disposed on said n+ GaN layer patterned into a plurality of elongated fingers and a metal layer disposed on the n&#x2212; doped GaN layer and forming a Schottky junction therewith. The layer thicknesses and the length and width of the elongated fingers are optimized to achieve a device with breakdown voltage of greater than 500 volts, current capacity in excess of one ampere, and a forward voltage of less than three volts.

Gallium nitride semiconductor device

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 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 repeatable and uniform low doped layer is formed using modulation doping by forming alternating sub-layers of doped and undoped nitride semiconductor material atop another layer. A Schottky diode is formed of such a low doped nitride semiconductor layer disposed atop a much more highly doped nitride semiconductor layer. The resulting device has both a low on-resistance when the device is forward biased and a high breakdown voltage when the device is reverse biased.

Low doped layer for nitride-based semiconductor device

A guard ring is formed in a semiconductor region that is part of a Schottky junction or Schottky diode. The guard ring is formed by ion implantation into the semiconductor contact layer without completely annealing the semiconductor contact layer to form a high resistance region. The guard ring may be located at the edge of the layer or, alternatively, at a distance away from the edge of the layer. A Schottky metal contact is formed atop the layer, and the edges of the Schottky contact are disposed atop the guard ring.

Non-activated guard ring for semiconductor devices

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 converter is provided having an AC input and a DC output. The converter includes a rectifier that receives the AC input and that provides a rectifier output, a series connected current to magnetic field energy storage device and current interrupter connected across the rectifier output and a series connected gallium nitride diode and output charge storage device connected between a midpoint of the series connected magnetic field energy storage device and current interrupter and a terminal of the rectifier output and wherein the converter is characterized in not needing a transient voltage suppression circuit.

GaN semiconductor based voltage conversion device

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 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

Light emitting diodes are provided with electrode and pad structures that facilitate current spreading and heat sinking. A light emitting diode may be formed as a die with a stacked structure having a first region and a mesa projecting from a surface of the first region. A first electrode may substantially cover the mesa and have a plurality of pads disposed thereon maximizing a contact area in relation to the first electrode. A second electrode may be disposed as a trace on the surface of the first region, the trace having a spiral, segmented/interdigitated, loop or pattern. Optionally, the trace includes corner spikes projecting outwardly toward edges of the first electrode.

Optimized contact design for flip-chip LED

A method of protecting and cleaning a semiconductor wafer using laser ablation includes the following steps: applies a protective coating on the side to be cut of a wafer with sapphire substrate, mounts the other side of the sapphire wafer on an adhesive tape, mounts the sapphire wafer on a cutting table, cuts the sapphire wafer with a laser, breaks the sapphire wafer into die, and cleans the sapphire wafer with a cleaning solution that removes slag resulting from the cutting, debris resulting from the breaking, and the protective coating, but the adhesive tape, the cleaning solution, and the protective coating are selected such that the cleaning solution does not damage the adhesive tape.

Growing community of inventors

Bound Brook, NJ, United States of America

Bryan S Shelton