Method of fabricating light emitting device through forming a template for growing semiconductor and separating growth substrate
A template for growing a semiconductor, a method of separating a growth substrate and a method of fabricating a light emitting device using the same are disclosed. The template for growing a semiconductor includes a growth substrate including a nitride substrate; a seed layer disposed on the growth substrate and including at least one trench; and a growth stop layer disposed on a bottom surface of the trench, wherein the trench includes an upper trench and a lower trench, and the upper trench has a smaller width than the lower trench.
1. A method of separating a substrate from an epitaxial layer of a template for growing a semiconductor device, the method comprising:
forming a mask pattern having a masking portion and an opening portion over a growth substrate, the mask pattern including a growth stop layer and an etching layer disposed over the growth stop layer and the growth substrate including a nitride substrate;
forming a seed layer over a bottom surface of the opening portion to include a lower seed layer disposed in the opening portion and an upper seed layer disposed over the lower seed layer and partially covering an upper surface of the masking portion;
forming at least one trench by removing the etching layer such that the growth stop layer remains on at least a portion of a bottom surface of the trench;
after forming of the at least one trench, increasing a size of the trench by removing a portion of the upper seed layer;
forming an epitaxial layer by growing the seed layer as a seed, the forming of the epitaxial layer including forming a void in at least a part of the trench; and
separating the growth substrate from the epitaxial layer.
2. The method of separating a substrate of claim 1 , wherein the trench includes an upper trench and a lower trench.
3. The method of separating a substrate of claim 2 ,
wherein the removing of the portion of the upper seed layer includes partially etching a lower surface of the upper seed layer that defines the lower trench together with a side of the lower seed layer.
4. The method of separating a substrate of claim 3 , wherein the seed layer includes n-type GaN, and a lower surface of the upper seed layer includes an N-face.
5. The method of separating a substrate of claim 4 , wherein the partial etching of the lower surface of the upper seed layer includes etching the lower surface of the upper seed layer using an etching solution including NaOH or KOH.
6. The method of separating a substrate of claim 5 , wherein the partially etched lower surface of the upper seed layer has a roughened surface.
7. The method of separating a substrate of claim 2 , wherein the epitaxial layer is grown from the upper seed layer through lateral growth and vertical growth to cover an upper portion of the trench.
8. The method of separating a substrate of claim 7 , wherein the forming of the epitaxial layer further including forming a pit at an upper portion of the void.
9. The method of separating a substrate of claim 1 , wherein the step of removing the etching layer exposes at least a part of the growth stop layer.
10. The method of separating a substrate of claim 1 , wherein the etching layer includes SiO 2 and the etching stop layer includes SiN x .
11. The method of separating a substrate of claim 10 , wherein the step of removing the etching layer uses an etching solution including buffered oxide etchant (BOE).
12. The method of separating a substrate of claim 1 , wherein the separating of the growth substrate includes applying stress to an interface between the growth substrate and the epitaxial layer.
13. The method of separating a substrate of claim 2 , wherein the separation of the growth substrate started from the epitaxial layer at a peripheral region of a lower surface of the lower seed layer.