Patent ID: 7893443

Claim:
A nitride-based semiconductor light-emitting device, comprising: an n-type clad layer made of n-type Al x1 In y1 Ga( 1-x1-y1 )N (where 0≦x 1 ≦1, 0≦y 1 ≦1, and 0≦x 1 +y 1 ≦1); a multiple quantum well-structured active layer made of undoped In A Ga 1-A N (where 0≦A<1) formed on the n-type clad layer; and a p-type clad layer formed on the multiple quantum well-structured active layer, including at least a first layer made of p-type In y2 Ga 1-y2 N (where 0≦y 2 <1) formed on the active layer and a second layer made of p-type Al x3 In y3 Ga( 1-x3-y3 )N (where 0<x 3 ≦1, 0≦y 3 ≦1, and 0<x 3 +y 3 ≦1) formed on the first layer; wherein the thickness of the first layer is smaller than the thickness of the second layer, wherein the first layer is substantially Al-free, and wherein the first layer is in contact with the multiple quantum well-structured active layer wherein the p-type clad layer further includes a third layer made of p-type In y4 Ga 1-y4 N (where 0≦y 4 <1) formed on the second layer; wherein the third layer consist of a low concentration p-type GaN semiconductor layer having a first doping concentration formed on the second layer, and a high concentration p-type GaN semiconductor layer having a concentration higher than the first doping concentration formed on the low concentration p-type GaN semiconductor layer.