LIGHT-EMITTING DEVICE

• US 20170250310A1
• Filed: 05/16/2017
• Published: 08/31/2017
• Est. Priority Date: 03/17/2011
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: HUANG, Chien-Fu, LIN, Shiuan-Leh, LU, Chih-Chiang, HSU, Chia-Liang
• Granted Patent: US 9,954,140 B2
• Time in Patent Office: Days
• 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 light-emitting device. The light-emitting device comprises: a substrate; an intermediate layer on the substrate; a first window layer comprising a first semiconductor optical layer on the intermediate layer and a second semiconductor optical layer on the first semiconductor optical layer; and a light-emitting stack on the second semiconductor optical layer; wherein a difference between the lattice constant of the intermediate layer and the lattice constant of the first semiconductor optical layer is greater than 2.3 Å.

Claims

1. A light-emitting device, comprising:

a substrate;

an intermediate layer on the substrate;

a first window layer comprising a first semiconductor optical layer on the intermediate layer and a second semiconductor optical layer on the first semiconductor optical layer; and

a light-emitting stack on the second semiconductor optical layer;

wherein a difference between the lattice constant of the intermediate layer and the lattice constant of the first semiconductor optical layer is greater than 2.3 Å

.

2. The light-emitting device of claim 1, wherein the first semiconductor optical layer comprises a higher defect density than that of the second semiconductor optical layer.

3. The light-emitting device of claim 1, wherein the intermediate layer and the first semiconductor optical layer comprise different group III-V semiconductor compounds and the substrate comprises a non-semiconductor material.

4. The light-emitting device of claim 1, further comprising a nucleation layer between the intermediate layer and the first window layer.

5. The light-emitting device of claim 4, wherein the first semiconductor optical layer comprises a phosphide semiconductor compound.

6. The light-emitting device of claim 4, wherein the intermediate layer comprises a nitride semiconductor compound and the nucleation layer comprises a phosphide semiconductor compound.

7. The light-emitting device of claim 4, further comprising:

a second window layer on a side of the light-emitting stack opposite to the first window layer; and

a passivation layer on the first window layer and the second window layer.

8. The light-emitting device of claim 7, further comprising a first electrode on the second window layer not covered by the passivation layer and a second electrode on the first window layer not covered by the passivation layer.

9. The light-emitting device of claim 7, wherein the passivation layer has a refractive index smaller than the refractive index of the second window layer.

10. The light-emitting device of claim 9, wherein the intermediate layer has a refractive index between the refractive index of the substrate and the refractive index of the nucleation layer or the first window layer.

11. The light-emitting device of claim 4, wherein an energy bandgap of the nucleation layer is between that of the intermediate layer and that of the light-emitting stack.

12. The light-emitting device of claim 4, wherein the nucleation layer is lattice matched with the first window layer and lattice mismatched with the intermediate layer.

13. The light-emitting device of claim 12, wherein the substrate is lattice mismatched with the intermediate layer.

14. The light-emitting device of claim 5, wherein the nucleation layer has a thickness less than a thickness of the first semiconductor optical layer.

15. The light-emitting device of claim 1, wherein the first semiconductor optical layer and the second semiconductor optical layer comprise the same material.

16. The light-emitting device of claim 1, further comprising a bonded interface between the first semiconductor optical layer and the second semiconductor optical layer.

17. The light-emitting device of claim 1, further comprising a reflective layer formed on a surface of the substrate opposite to the light-emitting stack.

18. The light-emitting device of claim 1, wherein the nucleation layer comprises gallium phosphide (GaP).

19. The light-emitting device of claim 18, wherein the intermediate layer comprises gallium nitride (GaN).

20. The light-emitting device of claim 1, wherein the intermediate layer comprises gallium nitride (GaN).