Light-emitting device

A light-emitting device, comprising:

• a substrate;
• an aluminum nitride (AlN) buffer layer formed on the substrate;
• a first semiconductor layer comprising AlxGa(1-x)N formed on the aluminum nitride (AlN) buffer layer, wherein x>0;
• a semiconductor pillar formed on the first semiconductor layer, comprising a second semiconductor layer and an active layer, wherein the semiconductor pillar comprises an outmost periphery;
• a first contact layer formed on the first semiconductor layer, wherein the first contact layer comprises a first contact portion and a first extending portion, wherein the first extending portion continuously surrounds an entirety of the outmost periphery of the semiconductor pillar and the first contact portion in a top view of the light-emitting device;
• a second contact layer formed on the second semiconductor layer of the semiconductor pillar;
• a first insulating layer formed on the first contact layer and the second contact layer, wherein the first insulating layer comprises one or multiple first openings exposing the first contact layer and one or multiple second openings exposing the second contact layer;
• a first electrode contact layer connected to the first contact portion through the one or multiple first openings of the first insulating layer, wherein the first electrode contact layer covers all of the first contact layer;
• a second electrode contact layer connected to the second contact layer through the one or multiple second openings of the first insulating layer;
• a second insulating layer formed on the first electrode contact layer and the second electrode contact layer, wherein the second insulating layer comprises one or multiple first openings exposing the first electrode contact layer and one or multiple second openings exposing the second electrode contact layer;
• a first electrode formed on the second insulating layer, wherein the first electrode covers the one or multiple first openings of the second insulating layer and is in contact with the first electrode contact layer to electrically connect to the first semiconductor layer by the first contact portion;
• and
• a second electrode formed on the second insulating layer, wherein the second electrode covers the one or multiple second openings of the second insulating layer and is in contact with the second electrode contact layer to electrically connect to the second semiconductor layer by the second contact layer.