Light-emitting structure having a plurality of light-emitting structure units

1. A light-emitting device, comprising:

a substrate, comprising a top surface;

a first light-emitting structure unit and a second light-emitting structure unit separately formed on the top surface and adjacent to each other, and wherein the first light-emitting structure unit comprises a first sidewall and a second sidewall;

a trench between the first and the second light-emitting structure units; and

an electrical connection arranged on the first sidewall and the second light-emitting structure unit, and electrically connecting the first light-emitting structure unit and the second light-emitting structure unit;

wherein the first sidewall connects to the top surface;

wherein the first sidewall faces the second light-emitting structure unit, and the second sidewall is not between the first light-emitting structure unit and the second light-emitting structure unit; and

wherein the second sidewall is steeper than the first sidewall.

2. The light-emitting device of claim 1 , wherein the first light-emitting structure unit comprises a bottom surface connecting to the first sidewall and the second sidewall, and a first angle between the first sidewall and the bottom surface is smaller than 80 degrees.

3. The light-emitting device of claim 2 , wherein a second angle between the second sidewall and the bottom surface is larger than the first angle.

4. The light-emitting device of claim 1 , wherein the trench comprises a bottom portion which is a part of the top surface and the trench has a cross-sectional profile of a rounded edge or a chamfered edge.

5. The light-emitting device of claim 4 , wherein the each of the first light-emitting structure unit and the second light-emitting structure unit comprises a lower layer having a first conductivity and an upper layer having a second conductivity; and

wherein the rounded edge or the chamfered edge is formed on the lower layer of the first light-emitting structure unit and/or is formed on the lower layer of the second light-emitting structure unit.

6. The light-emitting device of claim 5 , wherein the rounded edge has a radius not less than 1 μm.

7. The light-emitting device of claim 1 , wherein in a top view, the first light-emitting structure unit comprises a rectangular shape comprising four edges, and the first sidewall and the second sidewall are respectively arranged on two of the edges.

8. The light-emitting structure of claim 1 , wherein the second sidewall is devoid of the electrical connection arranged thereon.

9. The light-emitting device of claim 1 , wherein first light-emitting structure unit comprises a lower layer and an upper layer on the lower layer; wherein the lower layer comprises a mesa area surrounding the upper layer from a top view of the light-emitting structure.

10. The light-emitting device of claim 9 , wherein the electrical connection is arranged on the mesa area.

11. The light-emitting device of claim 1 , wherein the first sidewall comprises a step-like sidewall.

12. The light-emitting device of claim 1 , further comprising an isolation layer between the electrical connection and the first sidewall.

13. The light-emitting device of claim 12 , wherein the isolation layer comprises an edge with an acute angle in a cross-sectional view.

14. The light-emitting device of claim 1 , wherein the trench comprises a trapezoid cross section, wherein the trapezoid cross section comprises a first side with a length of 3 μm to 100 μm and a second side parallel to the first side with a length of 1 μm to 40 μm.

15. The light-emitting device of claim 1 , wherein the trench comprises a trapezoid cross section, wherein the trapezoid cross section comprises a first side and a second side parallel to the first side; and

a ratio of the first side to the second side is between 3:1 and 1.5:1.

16. A light-emitting device, comprising:

a substrate, comprising a top surface;

a first light-emitting structure unit and a second light-emitting structure unit separately formed on the top surface and spaced apart from each other, wherein each of the first light-emitting structure unit and the second light-emitting structure unit comprises a lower layer having a first conductivity and an upper layer having a second conductivity;

a trench between the first light-emitting structure unit and the second light-emitting structure unit, comprising a bottom portion which is a part of the top surface;

a first isolation layer, disposed on the trench and contacting the bottom portion and the lower layers of the first light-emitting structure unit and the second light-emitting structure unit; and

a second isolation layer, disposed on the trench and the first isolation layer; and

an electrical connection, formed on the first light-emitting structure unit and the second light-emitting structure unit and electrically connecting the first light-emitting structure unit and the second light-emitting structure unit;

wherein each of the lower layers comprises an inclined sidewall and the second isolation layer comprises an edge with an acute angle in a cross-sectional view, and

wherein the second isolation layer is between the electrical connection and the first isolation layer.

17. The light-emitting device of claim 16 , further comprising a current spreading layer formed on the upper layers of the first light-emitting structure unit and the second light-emitting structure unit.

18. The light-emitting device of claim 17 , wherein the electrical connection comprises one end contacting the current spreading layer.

19. The light-emitting device of claim 16 , further comprising a passivation formed on the electrical connection.

20. The light-emitting device of claim 19 ,

wherein the upper layer of the second light-emitting structure unit comprises a portion that is not shaded by the first isolation layer, and

wherein the passivation covers the portion of the upper layer of the second light-emitting structure unit.