The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 28, 2012
Filed:
Jul. 22, 2010
Leo J. Schowalter, Latham, NY (US);
Glen A. Slack, Scotia, NY (US);
J. Carlos Rojo, East Setau, NY (US);
Leo J. Schowalter, Latham, NY (US);
Glen A. Slack, Scotia, NY (US);
J. Carlos Rojo, East Setau, NY (US);
Crystal IS, Inc., Green Island, NY (US);
Abstract
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.