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:
Oct. 21, 2014
Filed:
Aug. 02, 2011
Zhen Chen, Pleasanton, CA (US);
Zhen Chen, Pleasanton, CA (US);
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A vertical GaN-based blue LED has an n-type GaN layer that was grown directly on Low Resistance Layer (LRL) that in turn was grown over a silicon substrate. In one example, the LRL is a low sheet resistance GaN/AlGaN superlattice having periods that are less than 300 nm thick. Growing the n-type GaN layer on the superlattice reduces lattice defect density in the n-type layer. After the epitaxial layers of the LED are formed, a conductive carrier is wafer bonded to the structure. The silicon substrate is then removed. Electrodes are added and the structure is singulated to form finished LED devices. In some examples, some or all of the LRL remains in the completed LED device such that the LRL also serves a current spreading function. In other examples, the LRL is entirely removed so that no portion of the LRL is present in the completed LED device.