System and method for producing polycrystalline group iii nitride articles and use thereof in production of single crystal group iii nitride articles
AssigneeHexatech, Inc.
InventorsRaoul Schlesser, Edward A. Preble
Life of this patent
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Abstract
The present disclosure relates to processes for producing single crystal Group III Nitride articles, polycrystalline Group III Nitride source materials suitable for use in such processes, and processes for producing polycrystalline Group III Nitride articles suitable for use as such source materials. The polycrystalline Group III Nitride source material can particularly be a grown material formed by vapor deposition methods, such as hydride vapor phase epitaxy (HYPE), and can be characterized by parameters such as purity, N/Al molar ratio, and relative density that are within defined ranges.
Claims20
A process for producing a single crystal Aluminum Nitride article comprising physical vapor transport (PVT) growth of the single crystal Aluminum Nitride article using a source material comprising a grown polycrystalline Aluminum Nitride mass.
A source material adapted for use in a physical vapor transport (PVT) growth process, the source material comprising a grown polycrystalline Aluminum Nitride mass that has been grown to have a thickness of about 2.5 cm or greater, to have at least one lateral dimension of about 12.5 cm or greater, to have an N/Al molar ratio of about 1, to have a relative density of at least 99%, and to have an aluminum nitride purity of at least 98% by weight.
A process for producing an Aluminum Nitride (AlN) single crystal via vapor phase transport (PVT), the process comprising:
- providing an AlN source material and an AlN seed within a reactor in a spaced apart orientation;
- and
- heating the AlN source material in a manner sufficient to form volatilized species from the AlN source material for transport to the AlN seed;
- wherein the AlN source material comprises a grown polycrystalline AlN mass that has been grown to have a thickness of about 2.5 cm or greater, to have at least one lateral dimension of about 3 cm or greater, to have an N/Al molar ratio of about 1, to have a relative density of at least 98%, and to have an aluminum nitride purity of at least 99% by weight.
An Aluminum Nitride (AlN) seed suitable for iterative growth of further generations of single crystal AlN, wherein:
- the AlN seed comprises a fraction of a previous generation single crystal AlN;
- and
- the (00.2) X-ray diffraction (XRD) Rocking curve full width at half maximum (FWHM) for a seed line arising from the AlN seed changes by no more than 10 arc seconds over at least three generations of the iterative growth.
A process for multi-generational Aluminum Nitride (AlN) single crystal seeded growth, the method comprising iteratively growing a next generation AlN single crystal using a seed from a previous generation AlN single crystal, said iterative growing utilizing a grown polycrystalline AlN mass of a suitable quality such that physical AlN single crystal size and at least one measure of single crystal AlN crystalline quality does not substantially decrease across at least three generations of the iterative growth.
Dependencies are inferred from the claim text.