Patent ID: 7576351

Claim:
A nitride semiconductor light generating device comprising: an n-type gallium nitride based semiconductor layer; a quantum well active layer including an In X1 Al Y1 Ga 1-X1-Y1 N (1>X1>0, 1>Y1>0) well layer and an In X2 Al Y2 Ga 1-X2-Y2 N (1>X2>0, 1>Y2>0) barrier layer; an In X3 Al Y3 Ga 1-X3-Y3 N (1>X3>0, 1>Y3>0) layer provided between the quantum well active layer and the n-type gallium nitride based semiconductor layer, an indium composition X3 of the In X3 Al Y3 Ga 1-X3-Y3 N layer being greater than an indium composition X1 of the In X1 Al Y1 Ga 1-X1-Y1 N well layer, an indium composition X3 of the In X3 Al Y3 Ga 1-X3-Y3 N layer being greater than an indium composition X2 of the In X2 Al Y2 Ga 1-X2-Y2 N barrier layer, an aluminum composition Y1 of the In X1 Al Y1 Ga 1-X1-Y1 N well layer being smaller than an aluminum composition Y3 of the In X3 Al Y3 Ga 1-X3-Y3 N layer, an aluminum composition Y2 of the In X2 Al Y2 Ga 1-X2-Y2 N barrier layer being smaller than an aluminum composition Y3 of the In X3 Al Y3 Ga 1-X3-Y3 N layer, and an oxygen concentration of the quantum well active layer being lower than that of the In X3 Al Y3 Ga 1-X3-Y3 N layer; and a p-type AlGaN layer having a bandgap energy greater than that of the In X2 Al Y2 Ga 1-X2-Y2 N barrier layer, the quantum well active layer being provided between the p-type AlGaN layer and the In X3 Al Y3 Ga 1-X3-Y3 N layer, wherein an oxygen concentration of the In X3 Al Y3 Ga 1-X3-Y3 N layer is greater than or equal to 1×10 18 cm −3 and lower than or equal to 1×10 20 cm −3 .