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:
May. 09, 2006
Filed:
Oct. 12, 2004
Liang-wen Wu, Banciao, TW;
Ru-chin Tu, Tainan, TW;
Cheng-tsang Yu, Wufong Township, Taichung County, TW;
Tzu-chi Wen, Tainan, TW;
Fen-ren Chien, Yonghe, TW;
Liang-Wen Wu, Banciao, TW;
Ru-Chin Tu, Tainan, TW;
Cheng-Tsang Yu, Wufong Township, Taichung County, TW;
Tzu-Chi Wen, Tainan, TW;
Fen-Ren Chien, Yonghe, TW;
Formosa Epitaxy Incorporation, Taoyuan, TW;
Abstract
A structure for the n-type contact layer in the GaN-based MQW LEDs is provided. Instead of using Si-doped GaN as commonly found in conventional GaN-based MQW LEDs, the n-type contact layer provided by the present invention achieves high doping density (>1×10cm) and low resistivity through a superlattice structure combining two types of materials, AlInGaN and AlInGaN (0≦m,n<1, 0<p,q<1, p+q≦1, m<p), each having its specific composition and doping density. In addition, by controlling the composition of Al, In, and Ga in the two materials, the n-type contact layer would have a compatible lattice constant with the substrate and the epitaxial structure of the GaN-based MQW LEDs. This n-type contact layer, therefore, would not chap from the heavy Si doping, have a superior quality, and reduce the difficulties of forming n-type ohmic contact electrode. In turn, the GaN-based MQW LEDs would require a lower operation voltage.