Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.