Semiconductor light emitting structure
A semiconductor light emitting structure including a substrate, a second type electrode layer, a reflecting layer, an insulating layer, a first type electrode layer, a first type semiconductor layer, an active layer and a second type semiconductor layer is provided. The second type electrode layer formed on the substrate has a current spreading grating formed by several conductive pillars and conductive walls, which are staggered and connected to each other. The reflecting layer and the insulating layer are formed on the second type electrode layer in sequence, and cover each conductive pillar and each conductive wall. The first type electrode layer, the first type semiconductor layer and the active layer are formed on the insulating layer in sequence. The second type semiconductor layer is formed on the active layer, and covers each conductive pillar and each conductive wall.
1. A semiconductor light emitting structure, comprising:
a substrate having a luminous zone and a non-luminous zone;
a second type electrode layer formed on the substrate, wherein a current spreading grating formed by a plurality of conductive pillars and a plurality of conductive walls, which are staggered and connected to each other, is formed within the luminous zone, and each conductive pillar and each conductive wall respectively have a first top surface and a second top surface parallel to the substrate;
a reflecting layer and an insulating layer formed on the second type electrode layer in sequence, wherein the reflecting layer and the insulating layer cover the conductive pillars and the conductive walls, and the first and the second top surface are exposed;
a first type electrode layer, a first type semiconductor layer, an active layer formed on the insulating layer located within the luminous zone in sequence;
a second type semiconductor layer formed on the active layer, wherein the second type semiconductor layer covers the conductive pillars and the conductive walls; and
a first contact pad formed on the first type electrode located within the non-luminous zone.
2. The semiconductor light emitting structure according to claim 1 , wherein the first type is P type, and the second type is N type.
3. The semiconductor light emitting structure according to claim 1 , wherein the first type is N type, and the second type is P type.
4. The semiconductor light emitting structure according to claim 1 , wherein the reflecting layer is formed by a metal layer or a Bragg reflecting layer.
5. The semiconductor light emitting structure according to claim 2 , wherein the reflecting layer is formed by a metal layer or a Bragg reflecting layer.
6. The semiconductor light emitting structure according to claim 3 , wherein the reflecting layer is formed by a metal layer or a Bragg reflecting layer.
7. The semiconductor light emitting structure according to claim 1 , wherein the current spreading grating comprises a polygonal basic structure formed by the conductive pillars and the conductive walls.
8. The semiconductor light emitting structure according to claim 7 , wherein the polygonal basic structure comprises triangle, square, rectangle, diamond, trapezoid or a combination thereof.
9. The semiconductor light emitting structure according to claim 1 , further comprising a second contact pad formed on the first top surface of each conductive pillar.
10. The semiconductor light emitting structure according to claim 1 , wherein the substrate is a conductive substrate or a heat-dissipating substrate.