Ostendo Technologies, Inc.

Technologies and Devices International, Inc.

Freiberger Compound Materials Gmbh

Vladimir Ivantsov

Vladimir A Dmitriev

Vitali Soukhoveev

Yuri V Melnik

Alexander L Syrkin

Katie Tsvetkov

Oleg V Kovalenkov

Alexander Usikov

Lisa Shapovalov

Hussein S El-Ghoroury

Anna Volkova

Benjamin A Haskell

Philippe Spiberg

Vladimir Sizov

Robert G W Brown

Lisa Shapovalova

Kaite Tsvetkov

Robert Brown

Alexander Syrkin

Hydride phase vapor epitaxy (HVPE) growth apparatus, methods and materials and structures grown thereby. An HVPE reactor includes generation, accumulation, and growth zones. A source material for growth of indium nitride is generated and collected inside the reactor. A first reactive gas reacts with an indium source inside the generation zone to produce a first gas product having an indium-containing compound. The first gas product is cooled and condenses into a liquid or solid condensate or source material having an indium-containing compound. The source material is collected in the accumulation zone. Vapor or gas resulting from evaporation of the condensate forms a second gas product, which reacts with a second reactive gas in the growth zone for growth of indium nitride.

HVPE apparatus and methods for growing indium nitride and indium nitride materials and structures grown thereby

A method for growing on a substrate strongly aligned uniform cross-section semiconductor composite nanocolumns is disclosed. The method includes: (a) forming faceted pyramidal pits on the substrate surface; (b) initiating nucleation on the facets of the pits; and; (c) promoting the growth of nuclei toward the center of the pits where they coalesce with twinning and grow afterwards together as composite nanocolumns. Multi-quantum-well, core-shell nanocolumn heterostructures can be grown on the sidewalls of the nanocolumns. Furthermore, a continuous semiconductor epitaxial layer can be formed through the overgrowth of the nanocolumns to facilitate fabrication of high-quality planar device structures or for light emitting structures.

Methods for producing composite GaN nanocolumns and light emitting structures made from the methods

A backflow liner in an epitaxial growth system is provided in order to control gas flow and protect the surface of substrates throughout an epitaxial growth cycle. The backflow liner provides critical protection during the warming time prior to substrate pre-treatment, while the growth environment reaches steady state condition between the pre-treatment and the growth process, during pauses between the layer depositions in case of multilayer structure growth, and during the cooling process. The direction of the gas flow through the backflow liner is counter to the deposition gas flows directed from the source end of the growth system. The backflow liner is therefore designed to shape the flow of gases to prevent formation of the vortex-type streams in the growth system that may negatively affect the growth process.

Backflow reactor liner for protection of growth surfaces and for balancing flow in the growth liner

A method has been developed to overcome deficiencies in the prior art in the properties and fabrication of semi-polar group III-nitride templates, films, and materials. A novel variant of hydride vapor phase epitaxy has been developed that provides for controlled growth of nanometer-scale periodic structures. The growth method has been utilized to grow multi-period stacks of alternating AlGaN layers of distinct compositions. The application of such periodic structures to semi-polar III-nitrides yielded superior structural and morphological properties of the material, including reduced threading dislocation density and surface roughness at the free surface of the as-grown material. Such enhancements enable to fabrication of superior quality semi-polar III-nitride electronic and optoelectronic devices, including but not limited to transistors, light emitting diodes, and laser diodes.

Semi-polar III-nitride films and materials and method for making the same

Apparatus and methods for controlling gas flows in a HVPE reactor. Gas flows may be controlled by a gas focusing element. Gas injection and gas collection tubes are positioned within an outer tube and are separated from each other to define a space there between. A gas, such as HCl gas, flows over the outer surfaces of the injection and collection tubes to contain gases within the space as they flow from the injection tube to the collection tube and over a seed upon which group III nitride materials are grown. Gas flows may also be controlled by a multi-tube structure that separates gases until they reach a grown zone. A multi-tube structure may include four tubes, which separate flows of a halide reactive gas, a reaction product that flows with a carrier gas, and ammonia.

Apparatus and methods for controlling gas flows in a HVPE reactor

A method to grow single phase group III-nitride articles including films, templates, free-standing substrates, and bulk crystals grown in semi-polar and non-polar orientations is disclosed. One or more steps in the growth process includes the use of additional free hydrogen chloride to eliminate undesirable phases, reduce surface roughness, and increase crystalline quality. The invention is particularly well-suited to the production of single crystal (11.2) GaN articles that have particular use in visible light emitting devices.

Free HCL used during pretreatment and AlGaN growth to control growth layer orientation and inclusions

The present invention relates to a method for producing a modified surface of a substrate that stimulates the growth of epitaxial layers of group-III nitride semiconductors with substantially improved structural perfection and surface flatness. The modification is conducted outside or inside a growth reactor by exposing the substrate to a gas-product of the reaction between hydrogen chloride (HCl) and aluminum metal (Al). As a single-step or an essential part of the multi-step pretreatment procedure, the modification gains in coherent coordination between the substrate and group-III nitride epitaxial structure to be deposited. Along with epilayer, total epitaxial structure may include buffer inter-layer to accomplish precise substrate-epilayer coordination. While this modification is a powerful tool to make high-quality group-III nitride epitaxial layers attainable even on foreign substrates having polar, semipolar and nonpolar orientation, it remains gentle enough to keep the surface of the epilayer extremely smooth. Various embodiments are disclosed.

Method for substrate pretreatment to achieve high-quality III-nitride epitaxy

A method of growing planar non-polar m-plane or semi-polar III-Nitride material, such as an m-plane gallium nitride (GaN) epitaxial layer, wherein the III-Nitride material is grown on a suitable substrate, such as an m-plane sapphire substrate, using hydride vapor phase epitaxy (HVPE). The method includes in-situ pretreatment of the substrate at elevated temperatures in an atmosphere of ammonia and argon, growing an intermediate layer such as an aluminum nitride (AlN) or aluminum-gallium nitride (AlGaN) on the annealed substrate, and growing the non-polar m-plane III-Nitride epitaxial layer on the intermediate layer using HVPE.

Growth of planar non-polar {1 -1 0 0} M-plane and semi-polar {1 1 -2 2} gallium nitride with hydride vapor phase epitaxy (HVPE)

HVPE reactors and methods for growth of p-type group III nitride materials including p-GaN. A reaction product such as gallium chloride is delivered to a growth zone inside of a HVPE reactor by a carrier gas such as Argon. The gallium chloride reacts with a reactive gas such as ammonia in the growth zone in the presence of a magnesium-containing gas to grow p-type group III nitride materials. The source of magnesium is an external, non-metallic compound source such as Cp2Mg.

HVPE apparatus and methods for growth of p-type single crystal group III nitride materials

Bulk GaN and AlGaN single crystal boules, preferably fabricated using a modified HVPE process, are provided. The single crystal boules typically have a volume in excess of 4 cubic centimeters with a minimum dimension of approximately 1 centimeter. If desired, the bulk material can be doped during growth, for example to achieve n-, i-, or p-type conductivity.

Bulk GaN and AlGaN single crystals

Hydride phase vapor epitaxy (HVPE) growth apparatus, methods and materials and structures grown thereby. A HVPE growth apparatus includes generation, accumulation and growth zones. A first reactive gas reacts with an indium source inside the generation zone to produce a first gas product having an indium-containing compound. The first gas product is transported to the accumulation zone where it cools and condenses into a source material having an indium-containing compound. The source material is collected in the accumulation zone and evaporated. Vapor or gas resulting from evaporation of the source material forms reacts with a second reactive gas in the growth zone for growth of ternary and quaternary materials including indium gallium nitride, indium aluminum nitride, and indium gallium aluminum nitride.

HVPE apparatus and methods for growth of indium containing materials and materials and structures grown thereby

An apparatus for growing bulk GaN and AlGaN single crystal boules, preferably using a modified HVPE process, is provided. The single crystal boules typically have a volume in excess of 4 cubic centimeters with a minimum dimension of approximately 1 centimeter. If desired, the bulk material can be doped during growth to achieve n-, i-, or p-type conductivity. In order to have growth cycles of sufficient duration, preferably an extended Ga source is used in which a portion of the Ga source is maintained at a relatively high temperature while most of the Ga source is maintained at a temperature close to, and just above, the melting temperature of Ga. To grow large boules of AlGaN, preferably multiple Al sources are used, the Al sources being sequentially activated to avoid Al source depletion and excessive degradation. In order to achieve high growth rates, preferably a dual growth zone reactor is used in which a first, high temperature zone is used for crystal nucleation and a second, low temperature zone is used for rapid crystal growth. Although the process can be used to grow crystals in which the as-grown material and the seed crystal are of different composition, preferably the two crystalline structures have the same composition, thus yielding improved crystal quality.

Reactor for extended duration growth of gallium containing single crystals

A method for growing bulk GaN and AlGaN single crystal boules, preferably using a modified HVPE process, is provided. The single crystal boules typically have a volume in excess of 4 cubic centimeters with a minimum dimension of approximately 1 centimeter. If desired, the bulk material can be doped during growth to achieve n-, i-, or p-type conductivity. In order to have growth cycles of sufficient duration, preferably an extended Ga source is used in which a portion of the Ga source is maintained at a relatively high temperature while most of the Ga source is maintained at a temperature close to, and just above, the melting temperature of Ga. To grow large boules of AlGaN, preferably multiple Al sources are used, the Al sources being sequentially activated to avoid Al source depletion and excessive degradation. In order to achieve high growth rates, preferably a dual growth zone reactor is used in which a first, high temperature zone is used for crystal nucleation and a second, low temperature zone is used for rapid crystal growth. Although the process can be used to grow crystals in which the as-grown material and the seed crystal are of different composition, preferably the two crystalline structures have the same composition, thus yielding improved crystal quality.

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Gaithersburg, MD, United States of America

Vladimir Ivantsov