Electrode of light-emitting device
A light-emitting device comprises a light-emitting semiconductor stack comprising a plurality of recesses and a mesa, each of the plurality of recesses comprising a bottom surface, and the mesa comprising an upper surface; a first electrode formed on the upper surface of the mesa; a plurality of second electrodes respectively formed on the bottom surface of the plurality of recesses; a first electrode pad formed on the light-emitting semiconductor stack and contacting with the first electrode; a second electrode pad formed on the light-emitting semiconductor stack and contacting with the plurality of second electrode; a first insulating layer comprising a plurality of passages to expose the plurality of second electrodes; and a second insulating layer comprising a plurality of spaces and formed on the first insulating layer, wherein the plurality of spaces is covered by the first electrode pad.
1. A light-emitting device, comprising:
a light-emitting semiconductor stack comprising a first semiconductor layer, an active layer on the first semiconductor layer, and a second semiconductor layer on the active layer, a recess comprising a bottom surface exposing the first semiconductor layer, and a mesa comprising an upper surface, wherein the upper surface is a surface of the second semiconductor layer and the bottom surface is a surface of the first semiconductor layer;
a first electrode comprising a first layer formed on the upper surface of the mesa and a second layer formed on the first layer, wherein the second layer is extended to cover the recess;
a second electrode formed on the bottom surface of the recess;
a first insulating layer formed in the recess and on the upper surface of the mesa, comprising an opening exposing the first layer of the first electrode and a passage exposing the second electrode;
a first electrode pad formed on the light-emitting semiconductor stack and electrically connected to the first electrode; and
a second electrode pad formed on the light-emitting semiconductor stack and electrically connected to the second electrode, wherein the first electrode pad and the second electrode pad are formed on the same side of the second semiconductor layer,
wherein in view of a first cross-section of the light-emitting device, the second electrode formed under the first electrode pad is covered by the second layer of the first electrode, and in view of a second cross-section of the light-emitting device, the second layer of the first electrode exposes a portion of the second electrode.
2. The light-emitting device according to claim 1 , further comprising a second insulating layer formed on the second layer of the first electrode, and comprising one or multiple spaces exposing the second layer of the first electrode.
3. The light-emitting device according to claim 2 , wherein the opening of the first insulating layer comprises a width larger than a width of the one or multiple spaces of the second insulating layer.
4. The light-emitting device according to claim 2 , wherein the second insulating layer comprises a material different from that of the first insulating layer.
5. The light-emitting device according to claim 4 , wherein a material of the second insulating layer comprises silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, or titanium oxide.
6. The light-emitting device according to claim 2 , wherein the second insulating layer is formed on the first insulating layer at a position overlapping a position of the first insulating layer.
7. The light-emitting device according to claim 2 , wherein the second insulating layer is between the second layer of the first electrode and the first electrode pad.
8. The light-emitting device according to claim 2 , wherein the first electrode pad is formed on the second insulating layer and electrically connected to the first electrode through the one or multiple spaces.
9. The light-emitting device according to claim 2 , wherein the second insulating layer directly contacts the first insulating layer at an edge of the light-emitting device.
10. The light-emitting device according to claim 2 , wherein the multiple spaces are separated from each other.
11. The light-emitting device according to claim 1 , further comprising a substrate on the light-emitting semiconductor stack, and the substrate is closer to the first semiconductor layer than to the second semiconductor layer.
12. The light-emitting device according to claim 1 , wherein the recess penetrates through the active layer and the second semiconductor layer to expose the first semiconductor layer.
13. The light-emitting device according to claim 1 , wherein the first electrode pad is formed on the recess.
14. The light-emitting device according to claim 1 , wherein the first layer comprises a first conductive material and the second layer comprises a second conductive material different from the first conductive material.
15. The light-emitting device according to claim 14 , wherein the first conductive material comprises a material comprising an element selected from the group consisting of Ag, Pt, and Au, and the second conductive material comprises a material comprising an element selected from a group consisting of Ni, Al, Cu, Cr, and Ti.
16. The light-emitting device according to claim 1 , wherein the first insulating layer is formed on a part of the upper surface of the mesa.
17. The light-emitting device according to claim 1 , wherein the second electrode pad is electrically connected to the second electrode through the passage of the first insulating layer.
18. The light-emitting device according to claim 1 , wherein the bottom surface is parallel to the upper surface.