Light-emitting device
The present disclosure provides a method for making a light-emitting device. The method includes steps of providing a first substrate; forming a first semiconductor layer on the first substrate; providing a second substrate; forming an intermediate layer on the second substrate, wherein a refractive index of the intermediate layer is between a refractive index of the second substrate and a refractive index of the first semiconductor layer; and bonding the first semiconductor layer and the intermediate layer.
1. A method for making a light-emitting device, comprising steps of:
providing a first substrate;
forming a first semiconductor layer having a textured surface on the first substrate;
providing a second substrate;
forming an intermediate layer on the second substrate, wherein a refractive index of the intermediate layer is between a refractive index of the second substrate and a refractive index of the first semiconductor layer; and
bonding the textured surface to the intermediate layer.
2. The method according to claim 1 , wherein the refractive index of the second substrate is smaller than the refractive index of the first semiconductor layer.
3. The method according to claim 1 , wherein the first semiconductor layer comprises gallium phosphide.
4. The method according to claim 1 , wherein the first semiconductor layer and the intermediate layer are bonded by a bonding layer.
5. The method according to claim 4 , wherein the bonding layer comprises a bilayer structure.
6. The method according to claim 4 , wherein the bonding layer comprises silicon oxide.
7. The method according to claim 4 , wherein the bonding layer comprises aluminum oxide.
8. The method according to claim 4 , wherein the intermediate layer has a width same as that of the bonding layer.
9. The method according to claim 4 , wherein the bonding layer is transparent.
10. The method according to claim 1 , wherein the first semiconductor layer is directly bonded to the intermediate layer.
11. The method according to claim 1 , further comprising forming a second semiconductor layer of AlGaInP between the first semiconductor layer and the first substrate.
12. The method according to claim 1 , further comprising forming a light-emitting stack comprising an n-type semiconductor layer, an active layer, and a p-type semiconductor layer between the first semiconductor layer and the first substrate.
13. The method according to claim 12 , wherein the p-type semiconductor layer is closer to the first semiconductor layer than the n-type semiconductor layer.
14. The method according to claim 12 , further comprising removing portions of the n-type semiconductor layer, the active layer, and the p-type semiconductor layer.
15. The method according to claim 12 , further comprising forming an insulation layer covering a side wall of the light-emitting stack.
16. The method according to claim 15 , wherein the insulation layer comprises a distributed Bragg reflector.
17. The method according to claim 1 , further comprising removing the first substrate after the bonding step.
18. The method according to claim 1 , further comprising forming a bonding layer on the first semiconductor layer prior to the bonding step.
19. The method according to claim 1 , wherein the second substrate comprises sapphire.
20. The method according to claim 1 , wherein the intermediate layer comprises gallium nitride.