Crystal Is, Inc.

J Carlos Rojo

Leo J Schowalter

Glen Alfred Slack

Robert T Bondokov

Kenneth E Morgan

Joseph A Smart

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

A method and apparatus for producing bulk single crystals of AlN having low dislocation densities of about 10,000 cmor less includes a crystal growth enclosure with Al and Nsource material therein, capable of forming bulk crystals. The apparatus maintains the Npartial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in the crystal growth enclosure. The Al and Nvapor is then deposited to grow single crystalline low dislocation density AlN at the nucleation site. High efficiency ultraviolet light emitting diodes and ultraviolet laser diodes are fabricated on low defect density AlN substrates, which are cut from the low dislocation density AlN crystals. Bulk crystals of ZnO may also be produced using the method.

A method and apparatus for producing bulk single crystals of AlN includes a crystal growth enclosure with Al and N source material therein, capable of forming bulk crystals. The apparatus maintains the N partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in crystal growth enclosure. The Al and N vapor is then deposited to grow single crystalline AlN at the nucleation site.

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Setauket, NY, United States of America

J Carlos Rojo