Method of forming a light-emitting device

1. A method of forming a light-emitting device comprising:

providing a growth substrate having a front side and a rear side;

forming a sacrificial layer on the front side of the growth substrate;

forming a protective structure on the sacrificial layer;

forming a light-emitting structure on the protective structure, wherein the light-emitting structure emits a first peak wavelength;

providing a carrier;

joining the carrier and the light-emitting structure; and

transforming the sacrificial layer by irradiating a laser beam from the rear side to separate the growth substrate from the light-emitting structure, wherein the laser beam emits a second peak wavelength, and wherein the protective structure reflects the second peak wavelength away from the light-emitting structure; wherein the protective structure comprises a first portion and a second portion, wherein the method further comprises removing the first portion, and forming an electrode on the second portion.

2. The method of forming the light-emitting device of claim 1 , further comprising forming a buffer structure between the growth substrate and the sacrificial layer.

3. The method of forming the light-emitting device of claim 1 , wherein the protective structure comprises a DBR structure, the DBR structure comprises a reflectivity of 99% or more in the second peak wavelength.

4. The method of forming the light-emitting device of claim 3 , wherein the DBR structure comprises semiconductor pairs, each of the semiconductor pairs comprises a first material layer having a first refractive index and a second material layer having a second refractive index, the first refractive index being greater than the second refractive index.

5. The method of forming the light-emitting device of claim 4 , wherein the first material layer comprises Al x Ga 1-x N (0.6≤x≤0.8), and the second material layer comprises Al y Ga 1-y N (0.9≤y≤1).

6. The method of forming the light-emitting device of claim 4 , wherein the first refractive index and the second refractive index are between 2.0 and 2.5.

7. The method of forming the light-emitting device of claim 4 , wherein a number of the semiconductor pairs is between 10 and 40.

8. The method of forming the light-emitting device of claim 1 , wherein the laser beam is irradiated by a KrF laser or an Nd:YAG laser.

9. The method of forming the light-emitting device of claim 1 , wherein the first peak wavelength and/or the second peak wavelength are between 210 and 400 nm, the first peak wavelength are different from the second peak wavelength.

10. The method of forming the light-emitting device of claim 2 , wherein the buffer layer comprises Al z Ga 1-z N (0.6≤z≤1).

11. The method of forming the light-emitting device of claim 1 , wherein the sacrificial layer comprises Al w Ga 1-w N (0≤w≤0.6).

12. The method of forming the light-emitting device of claim 1 , wherein the substrate comprises AlN or sapphire.

13. The method of forming the light-emitting device of claim 1 , wherein the sacrificial layer comprises an absorbance of 90% or more in the second peak wavelength.

14. The method of forming the light-emitting device of claim 2 , wherein the buffer structure comprises a transmittance of 90% or more in the second peak wavelength.

15. The method of forming the light-emitting device of claim 1 , wherein the growth substrate comprises a transmittance of 90% or more in the second peak wavelength.

16. The method of forming the light-emitting device of claim 1 , further comprising providing a bonding layer between the carrier and the light-emitting structure, wherein the carrier and the bonding layer are conductive material.

17. The method of forming the light-emitting device of claim 1 , further comprising forming a contact layer and a current blocking layer between the carrier and the light-emitting structure, wherein a material of the contact layer comprises Ag, and a material of the current blocking layer comprises SiO 2 .