Light emitting device
A light emitting device (LED) includes a stress control layer having a compressive stress on a substrate, a bonding layer on the stress control layer, a semiconductor layer on the bonding layer and including an active region for emitting light on the bonding layer, a first electrode on a lower surface of the substrate, and a second electrode on the semiconductor layer. The compressive stress of the stress control layer is between about 1 and about 20 GPa.
1. A light emitting device (LED) comprising:
a conductive semiconductor substrate;
a stress control layer on the conductive semiconductor substrate, the stress control layer having a compressive stress and including a conductive nitride;
a bonding layer on the stress control layer;
a semiconductor layer on the bonding layer, the semiconductor layer including an active region configured to emit light on the bonding layer;
a first electrode on a lower surface of the substrate; and
a second electrode on the semiconductor layer.
2. The LED of claim 1 , wherein the compressive stress of the stress control layer is between about 1 and about 20 GPa.
3. The LED of claim 2 , wherein the conductive nitride is one of titanium nitride (TiN) and tantalum nitride (TaN).
4. The LED of claim 1 , wherein a thickness of the stress control layer is in a range of about 10 nm to about 10 μm.
5. The LED of claim 2 , further comprising:
an adhesion layer between the stress control layer and the substrate.
6. The LED of claim 5 , wherein the adhesion layer includes titanium (Ti).
7. The LED of claim 2 , wherein the bonding layer is a conductive layer formed of one of tin (Sn), gold (Au), copper (Cu), silver (Ag), aluminum (Al), nickel (Ni) and alloys thereof.
8. A method of fabricating a light emitting diode (LED), the method comprising:
forming a semiconductor layer on a growth substrate, the semiconductor layer including an active region for emitting light;
forming a first bonding layer on the semiconductor layer;
forming a stress control layer on a conductive transfer substrate, the stress control layer having a compressive stress and including a conductive nitride;
forming a second bonding layer on the stress control layer;
bonding the growth substrate to the conductive transfer substrate by contacting the first bonding layer and the second bonding layer; and
removing the growth substrate.
9. The method of claim 8 , wherein the forming a stress control layer includes forming a nitride layer including a metal of a metal target on the transfer substrate by performing a reactive sputtering process on the metal target in an atmosphere of nitrogen.
10. The method of claim 9 , wherein the forming a nitride layer includes forming the metal target including one of titanium (Ti) and tantalum (Ta).
11. The method of claim 10 , wherein the forming a nitride layer includes supplying a volume of nitrogen gas between about 3 and about 5 times more than a volume of a carrier gas into a reactive sputtering chamber.
12. The method of claim 10 , wherein the forming a stress control layer includes forming the stress control layer to a thickness in a range of about 10 nm to about 10 μm.
13. The method of claim 10 , wherein the forming a stress control layer includes forming the stress control layer to have the compressive stress between about 1 and about 20 GPa.
14. The method of claim 8 , wherein the forming a first bonding layer and the forming a second bonding layer includes forming at least one of tin (Sn), gold (Au), copper (Cu), silver (Ag), aluminum (Al), nickel (Ni), and compounds thereof.
15. The method of claim 8 , further comprising:
forming an adhesion layer on the growth substrate before the forming a stress control layer.
16. The method of claim 15 , wherein the forming an adhesion layer includes forming titanium (Ti).
17. The method of claim 8 , wherein the transfer substrate is a conductive substrate, the method further comprising:
forming a first electrode on the transfer substrate; and
forming a second electrode on the semiconductor layer.