Light-emitting device

A light-emitting device, comprising:

• a substrate;
• a semiconductor stack on the substrate and comprising a first semiconductor layer, a second semiconductor layer, and an active layer between the first semiconductor layer and the second semiconductor layer, wherein the first semiconductor layer comprises a surrounding part exposing a first surface of the first semiconductor layer;
• a first contact layer contacting the first surface of the first semiconductor layer;
• a second contact layer formed on the second semiconductor layer, being surrounded by the first contact layer;
• a first insulating layer or a second insulating layer comprising a first opening exposing the first semiconductor layer and a second opening exposing the second semiconductor layer;
• and
• a third insulating layer covering the first insulating layer or the second insulating layer, wherein the third insulating layer comprises a first third insulating opening exposing the first contact layer and a second third insulating opening exposing the second contact layer.