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:
Jun. 24, 2014
Filed:
Jan. 26, 2012
Syn-yem HU, San Jose, CA (US);
Syn-Yem Hu, San Jose, CA (US);
Toshiba Techno Center Inc., Tokyo, JP;
Abstract
Gold is used as a micromask to roughen a gallium nitride (GaN) surface in an LED device. In one example, a mesh of ITO (Indium Tin Oxide) is formed on a GaN layer. The mesh has holes that extend down to the GaN. A layer of silicon dioxide is deposited so that it covers the GaN at the bottoms of the holes. A layer of gold is formed over the oxide. A thermal treatment causes the gold to ball up into small gold features. These gold features are used as a micromask in a subsequent etching step. Areas of the bottoms of the holes that are not covered by a gold feature are etched. Etching occurs through the oxide and down into the GaN. The roughening process involves no silver, and involves no harsh cleaning solvents or processes that might otherwise have been used were the micromask made of silver.