LIGHT-EMITTING DEVICE AND MANUFACTURING METHOD THEREOF

• US 20100200885A1
• Filed: 02/11/2010
• Published: 08/12/2010
• Est. Priority Date: 02/11/2009
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Ou, Chen, Chuang, Chia-Ming, Su, Win Jim, HSU, Chen Ke
• Granted Patent: US 8,492,780 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A light emitting device and a method of fabricating thereof are provided. The method of fabricating the light emitting device comprises: providing a substrate having a first major surface and a second major surface; forming a plurality of light-emitting stacks on the first major surface; forming an etching protection layer on each of the light emitting stacks; forming a plurality of holes by a discontinuous laser beam on the substrate; etching the plurality of holes; and slicing off the substrate along the plurality of holes to form a light emitting device. The light emitting device has a substrate wherein the sidewall of the substrate comprising a first area with a substantially flat surface and a second area with substantially textured surface.

Claims

1. A method of fabricating a light emitting device comprising:

providing a substrate, wherein the substrate comprises a first major surface and a second major surface;

forming a plurality of light emitting stack layers on the first major surface;

forming an etching protection layer on the plurality of light emitting stack layers;

forming a plurality of discontinuous holes on the substrate by a discontinuous laser beam;

etching the plurality of discontinuous holes; and

cleaving the substrate through the plurality of discontinuous holes.

2. The method of fabricating a light emitting device of claim 1, further comprising a step of removing the etching protection layer.

3. The method of fabricating a light emitting device of claim 1, wherein the step of forming a plurality of light emitting stack layers comprising:

forming a first conductive-type semiconductor layer on the first major surface of the substrate;

forming an active layer on the first conductive-type semiconductor layer;

forming a second conductive-type semiconductor layer on the active layer;

performing photolithography and etching process to etch the first conductive-type semiconductor layer, the active layer, and the second conductive-type semiconductor layer to form a mesa structure in each of a plurality of light emitting stack layers.

4. The method of fabricating a light emitting device of claim 1, wherein the step of etching the plurality of discontinuous holes is performed with an etching solution in a temperature ranging from 100 to 300 °

C. for a duration of about 10 to 50 minutes.

5. The method of fabricating a light emitting device of claim 4, wherein the etching solution is made of H₂SO₄ and H₃PO₄ with a concentration ratio 3:

1 or is only made of H₃PO₄.

6. The method of fabricating a light emitting device of claim 1, wherein the material of the etching protection layer is SiO₂ or SiNx.

7. The method of fabricating a light emitting device of claim 1, wherein the discontinuous laser beam is a pulsed laser beam.

8. The method of fabricating a light emitting device of claim 1, wherein the step of forming a plurality of discontinuous holes on the substrate by a discontinuous laser beam is performed on the first major surface or the second major surface of the substrate.

9. The method of fabricating a light emitting device of claim 1, further comprising a step of forming an electrode on the light emitting stack layer.

10. The method of fabricating a light emitting device of claim 9, further comprising a step of forming a transparent conductive oxide layer between the light emitting stack layer and the electrode.

11. A light emitting device comprising:

a substrate, wherein the substrate comprising a first major surface, a second major surface, and a sidewall;

a light emitting stack layer on the substrate, wherein the sidewall of the substrate comprising a first area and a second area;

wherein the morphology of the first area is substantially flat and the morphology of the second area is substantially textured.

12. The light emitting device of claim 11, wherein the second area is a convex-concave structure.

13. The light emitting device of claim 12, wherein an extension direction of the convex-concave structure is longitudinal.

14. The light emitting device of claim 12, wherein the extension direction of the convex-concave structure comprises a direction originating from the first major surface and extending toward the second major surface, a direction originating from the first major surface and extending away from the first major surface, and/or a direction originating from the second major surface and extending away from the second major surface.

15. The light emitting device of claim 12, wherein the extension direction of the convex-concave structure is substantially parallel to the normal line of the first major surface or that of the second major surface of the substrate.

16. The light emitting device of claim 11, wherein the first area is formed on the sidewall of the substrate and located close to the first major surface or the second major surface.

17. The light emitting device of claim 11, wherein the second area is formed on the sidewall of the substrate;

wherein the first area is sandwiched by two of the second areas.