Light-emitting device

• US 10,714,656 B2
• Filed: 04/23/2018
• Issued: 07/14/2020
• Est. Priority Date: 03/17/2011
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Hsu, Chia-Liang
• Primary Examiner(s): Tran, Tan N
• Application Number:
  US15/959,753
• Publication Number:
  US 20180240939A1
• Time in Patent Office: 813 Days
• Field of Search: 438458, 257 98
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

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.

Claims

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.