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:
Mar. 17, 2009
Filed:
Aug. 18, 2003
Valerie Bousquet, Oxford, GB;
Stewart Edward Hooper, Oxfordshire, GB;
Jennifer Mary Barnes, Oxford, GB;
Katherine L. Johnson, Oxford, GB;
Jonathan Heffernan, Oxford, GB;
Valerie Bousquet, Oxford, GB;
Stewart Edward Hooper, Oxfordshire, GB;
Jennifer Mary Barnes, Oxford, GB;
Katherine L. Johnson, Oxford, GB;
Jonathan Heffernan, Oxford, GB;
Sharp Kabushiki Kaisha, Osaki-shi, JP;
Abstract
A method of growing an AlGaN semiconductor layer structure by Molecular Beam Epitaxy comprises supplying ammonia, gallium and aluminum to a growth chamber thereby to grow a first (Al,Ga)N layer by MBE over a substrate disposed in the growth chamber. The first (Al,Ga)N layer has a non-zero aluminum mole fraction. Ammonia is supplied at a beam equivalent pressure of at least 1 10mbar, gallium is supplied at a beam equivalent pressure of at least 1 10mbar and aluminum is supplied at a beam equivalent pressure of at least 1 10mbar during the growth step. Once the first (Al,Ga)N layer has been grown, varying the supply rate of gallium and/or aluminum enables a second (Al,Ga)N layer, having a different aluminum mole fraction from the first (Al,Ga)N layer to be grown by MBE over the first (Al,Ga)N layer. This process may be repeated to grown an (Al,Ga)N multilayer structure.