Method of making a light emitting device and light emitting device made thereof
A light-emitting device, includes: a semiconductor stack, including a top surface, wherein the top surface includes a first region and a second region which are coplanar; a current barrier layer formed on the first region, wherein the current barrier layer includes an insulating material; and a transparent conductive layer formed on the current barrier layer and the second region; and a first electrode formed on the transparent conductive layer; wherein the current barrier layer includes: an electrode region at a position corresponding to the first electrode, having a shape substantially the same as the first electrode; and a plurality of extension regions extending from the electrode region and not covered by the first electrode.
1. A light-emitting device, comprising:
a semiconductor stack, comprising a top surface, wherein the top surface comprises a first region and a second region which are coplanar;
a current barrier layer formed on the first region, wherein the current barrier layer comprises an insulating material; and
a transparent conductive layer formed on the current barrier layer and the second region; and
a first electrode formed on the transparent conductive layer;
wherein the current barrier layer comprises:
an electrode region at a position corresponding to the first electrode, having a shape substantially the same as the first electrode; and
a plurality of extension regions extending from the electrode region and not covered by the first electrode.
2. The light-emitting device of claim 1 , wherein the first electrode comprises a first electrode pad and a first extended electrode, and the electrode region of the current barrier layer is under the first electrode pad and the first extended electrode.
3. The light-emitting device of claim 2 , wherein the plurality of extension regions and the first extended electrode extend toward different directions.
4. The light-emitting device of claim 1 , wherein the semiconductor stack comprises four sides and the plurality of extension regions extends toward the four sides.
5. The light-emitting device of claim 1 , wherein the semiconductor stack comprises a first type semiconductor layer, a second semiconductor layer and an active layer therebetween; and wherein the current barrier layer and the first electrode are formed on the second semiconductor layer.
6. The light-emitting device of claim 5 , further comprising:
a second electrode formed on and electrically connecting to the first type semiconductor layer;
wherein the first electrode comprises a first electrode pad and a first extended electrode;
wherein the semiconductor stack comprises a first side, a second side opposite to the first side, a third side and a fourth side opposite to the third side;
wherein the first electrode pad and the second electrode are near the first side and the second side, respectively; and
wherein part of the plurality of extension regions extends toward the third side and the fourth side.
7. The light-emitting device of claim 6 , wherein one of the plurality of extension regions extends toward the first side.
8. The light-emitting device of claim 6 , wherein the first extended electrode extends toward the second side.
9. The light-emitting device of claim 6 , wherein part of the plurality of extension regions extends from the electrode region which is under the first electrode pad toward at least one of the first side, the second side, the third side and the fourth side.
10. The light-emitting device of claim 1 , wherein the current barrier layer has a sidewall and a bottom surface facing the first region and an angle between the sidewall and the bottom surface is between 10°-70°.
11. The light-emitting device of claim 10 , wherein the transparent conductive layer is formed between the sidewall of the current barrier layer and the second region of the semiconductor stack, wherein a difference between a thickness of the transparent conductive layer at the sidewall on the current barrier layer and a thickness of the transparent conductive layer on the second region of the semiconductor stack forms a ratio not larger than 10%.
12. The light-emitting device of claim 1 , wherein the current barrier layer comprises silicon oxide (SiO 2 ), silicon nitride (SiN x ) or titanium dioxide (TiO 2 ).
13. The light-emitting device of claim 1 , wherein the current barrier layer has a resistance larger than 10 14 Ω-cm.
14. The light-emitting device of claim 1 , wherein the transparent conductive layer contacts the second region.
15. The light-emitting device of claim 1 , further comprising:
a substrate under the semiconductor stack, wherein the substrate comprises an inclined sidewall.
16. The light-emitting device of claim 15 , wherein the inclined sidewall comprises a rough surface.
17. The light-emitting device of claim 1 , wherein in a top view, the electrode region of the current barrier layer has a width larger than that of the first electrode.
18. The light-emitting device of claim 1 , wherein an area of the first region enclosed by a contour of the electrode region of the current barrier layer is larger than an area of the first region covered by the first electrode.