LED having vertical structure and method for fabricating the same
View Patent ↗A light emitting diode (LED) having a vertical structure and a method for fabricating the same. The light emitting diode (LED) having a vertical structure includes a support layer; a first electrode formed on the support layer; a plurality of semiconductor layers formed on the first electrode; a conductive semiconductor layer formed on the plurality of semiconductor layer and provided with an outer surface having a tilt angle of a designated degree; and a second electrode formed on the conductive semiconductor layer.
1. A light emitting diode (LED) having a vertical structure comprising:
a support layer;
a first electrode on the support layer, the first electrode comprising an electrical contact and a reflective electrode on the electrical contact;
a semiconductor structure on the first electrode, the semiconductor structure including a first-type layer, an active layer, and a second-type layer;
a conductive semiconductor layer directly on the semiconductor structure, and provided with an outer surface having a tilt angle in the range of 35˜65°; and
a second electrode on a surface of the conductive semiconductor layer,
wherein the conductive semiconductor layer is configured to emit the light from the semiconductor structure through the surface of the conductive semiconductor layer, and
wherein the outer surface of the conductive semiconductor layer is configured to reduce a possibility of internal total reflection of the light emitted from the semiconductor structure thereby improving the light extraction efficiency of the diode.
2. The LED according to claim 1 , wherein the tilt angle of the outer surface of the conductive semiconductor layer is an angle between an upper surface and a side surface of the conductive semiconductor layer.
3. The LED according to claim 1 , wherein the conductive semiconductor layer comprises a conductive GaN layer having a thickness of 1˜300 μm.
4. The LED according to claim 1 , wherein at least one of the support layer, the first electrode, the semiconductor structure, the conductive semiconductor layer, and the second electrode has a horizontal sectional shape of a polygon, which is more than a rectangle.
5. The LED according to claim 4 , wherein at least one of the support layer, the first electrode, the semiconductor structure, the conductive semiconductor layer, and the second electrode has a horizontal sectional shape of a polygon having at least 6 angles.
6. The LED according to claim 1 , wherein the support layer comprises at least one of a silicon (Si) substrate, a gallium arsenide (GaAs) substrate, a germanium (Ge) substrate, a metal substrate, and a substrate including metal.
7. The LED according to claim 1 , wherein the support layer comprises nickel (Ni) or copper (Cu).
8. The LED according to claim 1 , wherein the thickness of the conductive semiconductor layer is thicker than that of the semiconductor structure.
9. The LED according to claim 1 , further comprising a seed metal arranged between the support layer and the first electrode.
10. The LED according to claim 1 , wherein an outer surface of the semiconductor structure has a different angle from the tilt angle of the outer surface of the conductive semiconductor layer.
11. The LED according to claim 1 , wherein the tilt angle of the outer surface of the conductive semiconductor layer is an angle between an upper surface and a side surface of the conductive semiconductor layer, which is in the range of 53˜56°.
12. The LED according to claim 1 , wherein the tilt angle of the outer surface of the conductive semiconductor layer is configured such that the surface of the conductive semiconductor layer is larger than a surface of the conductive semiconductor layer contacting the semiconductor structure.