Patent ID: 7042019
Filing Date: 2006-05-09
Classification: B82Y,H01L

Abstract:
1. A GaN-based MQW LED structure, comprising: a substrate made of a material selected from the group consisting of sapphire, 6H-SiC, 4H-SiC, Si, ZnO, GaAs, MgAl a buffer layer made of Al an n-type contact layer located on top of said buffer layer; an active layer made of InGaN located on top of a part of said n-type contact layer's upper surface; a negative electrode located on top of another part of said n-type contact layer's upper surface not covered by said active layer; a p-type cladding layer made of Mg-doped Al a p-type contact layer made of Mg-doped Al a positive electrode located on top of a part of said p-type contact layer's upper surface, wherein said n-type contact layer has a superlattice structure formed by a first number of first base layers made of an n-type group III nitride, and a second number of second base layers made of another n-type group III nitride, alternately stacked on top of each other, said second base layers have wider band gaps than those of said first base layers, a bottommost base layer of said n-type contact layer is selected from the group consisting of said first base layer and said second base layer, and a topmost base layer is selected from the group consisting of said first base layer and said second base layer; and wherein each or said first base layers is made of In- and Si-codoped GaN having a doping density independent of other base layers, and each of said second base layers is made of In- and Si-codoped Al