Crystal Is, Inc.

Rf Micro Devices, Inc.

Cornell Research Foundation Inc.

Joseph A Smart

Leo J Schowalter

Jeffrey Blanton Shealy

Robert T Bondokov

Glen Alfred Slack

Kenneth E Morgan

Shawn Gibb

Brook Hosse

David Grider

Shiwen Liu

James R Grandusky

Juan Carlos Rojo

James R Shealy

Shawn Robert Gibb

Timothy J Bettles

J Carlos Rojo

In various embodiments, a semiconductor device includes an aluminum nitride single-crystal substrate, a pseudomorphic strained layer disposed thereover that comprises at least one of AlN, GaN, InN, or an alloy thereof, and, disposed over the strained layer, a semiconductor layer that is lattice-mismatched to the substrate and substantially relaxed.

Thick pseudomorphic nitride epitaxial layers

Bulk single crystals of AlN having a diameter greater than about 25 mm and dislocation densities of about 10,000 cmor less and high-quality AlN substrates having surfaces of any desired crystallographic orientation fabricated from these bulk crystals.

Method and apparatus for producing large, single-crystals of aluminum nitride

Semiconductor structures are fabricated to include strained epitaxial layers exceeding a predicted critical thickness thereof.

Semiconductor structures and devices based thereon include an aluminum nitride single-crystal substrate and at least one layer epitaxially grown thereover. The epitaxial layer may comprise at least one of AlN, GaN, InN, or any binary or tertiary alloy combination thereof, and have an average dislocation density within the semiconductor heterostructure is less than about 10cm.

Nitride semiconductor heterostructures and related methods

A high voltage and high power gallium nitride (GaN) transistor structure is disclosed. A plurality of structural epitaxial layers including a GaN buffer layer is deposited on a substrate. A GaN termination layer is deposited on the plurality of structural epitaxial layers. The GaN termination layer is adapted to protect the plurality of structural epitaxial layers from surface reactions. The GaN termination layer is sufficiently thin to allow electrons to tunnel through the GaN termination layer. Electrical contacts are deposited on the GaN termination layer, thereby forming a high electron mobility transistor.

High voltage GaN-based transistor structure

The present invention relates to a high voltage and high power gallium nitride (GaN) transistor structure. In general, the GaN transistor structure includes a sub-buffer layer that serves to prevent injection of electrons into a substrate during high voltage operation, thereby improving performance of the GaN transistor structure during high voltage operation. Preferably, the sub-buffer layer is aluminum nitride, and the GaN transistor structure further includes a transitional layer, a GaN buffer layer, and an aluminum gallium nitride Schottky layer.

The present invention relates to passivation of a gallium nitride (GaN) structure before the GaN structure is removed from an epitaxial growth chamber. The GaN structure includes one or more structural epitaxial layers deposited on a substrate, and the passivation layer deposited on the structural epitaxial layers. In general, the passivation layer is a dielectric material deposited on the GaN structure that serves to passivate surface traps on the surface of the structural epitaxial layers. Preferably, the passivation layer is a dense, thermally deposited silicon nitride passivation layer.

Surface passivation of GaN devices in epitaxial growth chamber

A single step process for nucleation and subsequent epitaxial growth on a lattice mismatched substrate is achieved by pre-treating the substrate surface with at least one group III reactant or at least one group II reactant prior to the introduction of a group V reactant or a group VI reactant. The group III reactant or the group II reactant is introduced into a growth chamber at an elevated growth temperature to wet a substrate surface prior to any actual crystal growth. Once the pre-treatment of the surface is complete, a group V reactant or a group VI reactant is introduced to the growth chamber to commence the deposition of a nucleation layer. A buffer layer is then grown on the nucleation layer providing a surface upon which the epitaxial layer is grown preferably without changing the temperature within the chamber.

Single step, high temperature nucleation process for a lattice mismatched substrate

The present invention relates to an epitaxial structure having one or more structural epitaxial layers, including a gallium nitride (GaN) layer, which is deposited on a substrate, and a method of growing the epitaxial structure, wherein the structural epitaxial layers can be separated from the substrate. In general, a sacrificial epitaxial layer is deposited on the substrate between the substrate and the structural epitaxial layers, and the structural epitaxial layers are deposited on the sacrificial layer. After growth, the structural epitaxial layers are separated from the substrate by oxidizing the sacrificial layer. The structural epitaxial layers include a nucleation layer deposited on the sacrificial layer and a gallium nitride layer deposited on the nucleation layer. Optionally, the oxidation of the sacrificial layer may also oxidize the nucleation layer.

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Mooresville, NC, United States of America

Joseph A Smart