OPTOELECTRONIC DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20140145224A1
• Filed: 11/26/2012
• Published: 05/29/2014
• Est. Priority Date: 11/26/2012
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Hsu, Tzu Chieh, Lin, Ching-Pei, Hsu, Yen Ming, Wei, Shou-Chin
• Granted Patent: US 9,276,164 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0025 relating to coatings
• 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 33/0062 for devices with an active region comprising only III-V compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

A method of fabricating an optoelectronic device, comprising: providing a first substrate; forming an epitaxial stack on the first substrate wherein the epitaxial stack comprising a first conductive-type semiconductor layer, an active layer and a second conductive-type semiconductor layer; etching an upper surface of the second conductive-type semiconductor layer and forming a first texture profile on the upper surface of the second conductive-type semiconductor layer; forming a passivation layer on the upper surface of the second conductive-type semiconductor layer; and etching an upper surface of the passivation layer forming a second texture profile on the upper surface of the passivation layer wherein the first texture profile is different from the second texture profile.

Claims

1. A method of fabricating an optoelectronic device, comprising:

providing a first substrate;

forming an epitaxial stack on the first substrate wherein the epitaxial stack comprising a first conductive-type semiconductor layer, an active layer and a second conductive-type semiconductor layer;

etching an upper surface of the second conductive-type semiconductor layer and forming a first texture profile on the upper surface of the second conductive-type semiconductor layer;

forming a passivation layer on the upper surface of the second conductive-type semiconductor layer; and

etching an upper surface of the passivation layer forming a second texture profile on the upper surface of the passivation layer wherein the first texture profile is different from the second texture profile.

2. The method of fabricating the optoelectronic device of claim 1, wherein the method to etch the upper surface of the second conductive-type semiconductor layer can be wet etching, electrochemical etching, or dry etching.

3. The method of fabricating the optoelectronic device of claim 1, wherein the method to etch the upper surface of the passivation layer can be wet etching.

4. The method of fabricating the optoelectronic device of claim 1, wherein the material of the epitaxial stack contains one element selected from the group consisting of Al, Ga, In, As, P, and N.

5. The method of fabricating the optoelectronic device of claim 1, wherein the depth of the first texture profile can be 10 nm-3000 nm.

6. The method of fabricating the optoelectronic device of claim 1, wherein the depth of the second texture profile can be 10 nm-3000 nm.

7. The method of fabricating the optoelectronic device of claim 1, further comprising steps of providing a second substrate and an adhesion layer, and bond the lower surface of the first conductive-type semiconductor layer to the second substrate the adhesion layer.

8. The method of fabricating the optoelectronic device of claim 7, further comprising a step of forming at least one of a transparent conductive layer, a current blocking layer, and a reflective layer between the adhesion layer and the second electrode.

9. The method of fabricating the optoelectronic device of claim 1, further comprising a step of exposing partial of the first conductive-type semiconductor layer wherein partial of the passivation layer is formed on the exposed first conductive-type semiconductor layer.

10. The method of fabricating the optoelectronic device of claim 1, further comprising a step to etch the sidewall of the passivation layer by wet etching.

11. An optoelectronic device comprising:

a first substrate;

an epitaxial stack formed on the first substrate wherein the epitaxial stack comprising a first conductive-type semiconductor layer, an active layer and a second conductive-type semiconductor layer wherein the upper surface of the second conductive-type semiconductor layer comprising a first texture profile; and

a passivation layer formed on the upper surface of the second conductive-type semiconductor layer wherein the upper surface of the passivation layer comprising a second texture profile different from the first texture profile.

12. The optoelectronic device of claim 11, wherein the material of the epitaxial stack contains one element selected from the group consisting of Al, Ga, In, As, P, and N.

13. The optoelectronic device of claim 11, wherein the depth of the first texture profile can be 10 nm-5000 nm.

14. The optoelectronic device of claim 11, wherein the depth of the second texture profile can be 10 nm-5000 nm.

15. The optoelectronic device of claim 11, wherein the sidewall of the passivation layer comprising a third texture profile.

16. The optoelectronic device of claim 11, wherein the first refractive index (n₁) of the passivation layer is smaller than the second refractive index (n₂) of the second conductive-type semiconductor layer.

17. The optoelectronic device of claim 16, wherein the first refractive index (n₁) of the passivation layer can be 2.4>

n₁≧

1.9, and the second refractive index (n₂) of the second conductive-type semiconductor layer can be 3.3≧

n₂≧

2.4.

18. The optoelectronic device of claim 11, wherein the passivation layer can be a multilayer structure and/or the upper surface of each of the sub layer can be a texture surface.

19. The optoelectronic device of claim 18, wherein the passivation layer comprising at least a first sub layer formed on the upper surface of the second conductive-type semiconductor layer having a third refractive index (n₃) and a second sub layer formed on the first sub layer 507a having a fourth refractive index (n₄) wherein the third refractive index (n₃) can be 2.4>

n₃>

1.9, the fourth refractive index (n₄) can be smaller than or equal to 1.9.

20. The optoelectronic device of claim 11, wherein first texture profile and second texture profile comprising pore, void, pinhole, cavity or porous structure, and the shape of the first texture profile and second texture profile can be circle, hexagon, dodecagon, conical, or pyramidal shapes.