Patent ID: 8592822
Filing Date: 2013-11-26
Classification: H01L

Abstract:
1. A light emitting device comprising: an n-type semiconductor layer comprising a first area and a second area in a plane; an n-type contact layer disposed on the n-type semiconductor layer and has a first thickness in the first area and a second thickness in the second area; an undoped semiconductor layer disposed on the n-type contact layer having the first thickness in the first area; an active layer disposed on the undoped semiconductor layer in the first area; a p-type semiconductor layer disposed on the active layer in the first area; a first electrode disposed on the n-type contact layer having the second thickness in the second area; and a second electrode disposed on the p-type semiconductor layer, wherein the undoped semiconductor layer has a thickness of less than or equal to 300 nm, wherein a height difference between the top surface of the n-type contact layer in the first area and the top surface of the n-type contact layer in the second area is at least 100 nm, wherein the p-type semiconductor layer comprises a first semiconductor layer having a first dopant concentration, a second semiconductor layer having a second dopant concentration, a third semiconductor layer having a third dopant concentration, and a fourth semiconductor layer having a fourth dopant concentration, wherein the second dopant concentration has a smaller value than the first dopant concentration and the third dopant concentration, and wherein the fourth dopant concentration has a greater value than the third dopant concentration.