Emcore Corporation

Velox Semiconductor Corporation

Other

Power Integrations, Inc.

Veeco Instruments Inc.

Richard A Stall

Craig Royden Nelson

Michael Murphy

Bryan S Shelton

Milan Pophristic

Alexander I Gurary

LinLin Liu

Alex D Ceruzzi

Norman E Schumaker

Wilfried R Wagner

Ivan Eliashevich

Gary S Tompa

Mark Gottfried

Boris Peres

Marek Pabisz

TingGang Zhu

Vadim Boguslavskiy

Xiang Gao

Alex Gurary

Robert Frank Karlicek, Jr

Shiping Guo

David Gotthold

Thomas Salagaj

Peter Zawadzki

Douglas A Collins

Eric A Armour

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

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 wafer carrier for growing wafers includes a plate having a first surface and a second surface, a plurality of openings extending from the first surface to the second surface of the plate, and a porous element disposed in each of the plurality of openings, each porous element being adapted to support one or more wafers. The wafer carrier also has a blind central opening extending from the second surface toward the first surface of the plate, and a plurality of shafts extending outwardly from the blind central opening. Each shaft has a first end in communication with the blind central opening and a second end in communication with one of the porous elements for providing fluid communication between the blind central opening and one of the porous elements. Suction is formed at a surface of each porous element by drawing vacuum through the blind central opening and the shafts.

Wafer carrier for growing GaN wafers

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

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

Reactors for growing epitaxial layers on substrates are disclosed including rotatable substrate carriers and injectors for injecting gases into the reactor towards the substrates on the carriers and including a gas separator for separately maintaining various gases between gas inlets and the injector. Various reactor embodiments are disclosed including removable gas separators, and particular injectors which include cooling channels, as well as flow restrictors mounted within the reactors to restrict the flow of the gases to the substrates from the injector, and heaters mounted within the rotatable shell holding the substrate carriers so that the heaters can be accessed and removed through a lid forming a wall of the reactor.

Chemical vapor deposition apparatus

A wafer carrier/susceptor combination for use in an epitaxial deposition process has a configuration which provides greater thermal conductivity between the susceptor and the wafer carrier in regions substantially underlying the wafers than in regions not underlying the wafers. This difference in thermal conductivity is produced by configuring the wafer carrier or susceptor so that the lower surface of the wafer carrier is disposed closer to the susceptor in regions substantially underlying the wafers than in at least some regions not underlying the wafers. By controlling the thermal conductivity so that it is greater in certain regions than in other regions, the temperature difference between the wafers and the surface of the wafer carrier can be reduced, and a more uniform temperature distribution across the surface of the wafer can be achieved. As a result, the combination may be used to deposit a more uniform coating across the entire surface of each wafer.

Wafer carriers for epitaxial growth processes

An apparatus for depositing a coating on a substrate substantially eliminates the occurrence of oval defects by creating a heated tortuous path through which the source material vapors must travel before depositing on the substrate. In addition, shut-off valves for each of the source materials are positioned in the reaction chamber in close proximity to the substrate, thereby enabling layers of different compositions to be deposited with sharp transitions between adjacent layers. The apparatus may be used to efficiently coat large areas uniformly, and works equally well with either elemental or chemical source materials, or certain combinations of both. The features of the coating apparatus may be embodied in replacement source cells for retrofitting in conventional molecular beam and chemical beam epitaxy units.

Apparatus for depositing a coating on a substrate

Substrates such as semiconductor wafers are treated with a gas by advancing the substrate along a path, preferably a circular path through the gas while maintaining a face of the substrate transverse, preferably oblique, to the path so that the gas contacts be exposed from the face of the substrate. Preferably, a plurality of substrates are treated simultaneously, and the substrates serve as vanes to impel the gas into rotational motion, thereby pumping the gas through the process chamber. Preferably, the substrates are carried on susceptors having generally planar faces, the susceptors also serving as vanes impelling the gas into rotational motion. The gas may be a depositing gas for forming epitaxial layers on the faces of the substrates, or an etching gas.

Gas treatment apparatus and method

Substrates such as semiconductor wafers are treated with a gas by advancing the substrate along a path, preferably a circular path through the gas while maintaining a face of the substrate transverse, preferably oblique, to the path so taht the gas contacts be exposed from the face of the substrate. Preferably, a plurality of substrates are treated simultaneously, and the substrates serve as vanes to impel the gas into rotational motion, thereby pumping the gas through the process chamber. Preferably, the substrates are carried on susceptors having generally planar faces, the susceptors also serving as vanes impelling the gas into rotational motion. The gas may be a depositing gas for forming epitaxial layers on the faces of the substrates, or an etching gas.

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Belle Mead, NJ, United States of America

Richard A Stall