Light emitting device

• US 9,166,105 B2
• Filed: 12/28/2012
• Issued: 10/20/2015
• Est. Priority Date: 04/19/2011
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Kuo, De-Shan, Ko, Ting-Chia, Tu, Chung-Hsiang
• Primary Examiner(s): Lee, Cheung
• Application Number:
  US13/729,842
• Publication Number:
  US 20140048830A1
• Time in Patent Office: 1,026 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 31/02363 of the semiconductor body itself, e.g. textured active layers
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A light-emitting device includes: a substrate; a first semiconductor layer disposed on the substrate and having a first surface; a rough structure formed in the first semiconductor layer, the rough structure comprising porous structures formed therein and a portion of the porous structures having openings exposed on the first surface of the first semiconductor layer; and an active layer formed on the first semiconductor layer.

Claims

1. A light-emitting device comprising:

a substrate;

a first semiconductor layer disposed on the substrate and having a first surface;

a rough structure formed in the first semiconductor layer, the rough structure comprising porous structures formed therein and a portion of the porous structures having openings exposed on the first surface of the first semiconductor layer; and

an active layer formed on the first semiconductor layer.

2. The lighting-emitting device of claim 1, wherein the porous structures have a portion not covered by the active layer.

3. The lighting-emitting device of claim 1, wherein the rough structure further comprises a pore, a void, a bore, a pinhole, or a cavity.

4. The lighting-emitting device of claim 1, wherein the first semiconductor layer has a second surface, wherein the second surface is parallel to a surface of the substrate and connects the first surface, and a portion of the porous structures has openings formed and exposed on the second surface.

5. The lighting-emitting device of claim 4, further comprising a second electrode formed on the second surface of the first semiconductor layer.

6. The lighting-emitting device of claim 4, wherein an average width of the openings exposed on the first surface is different from an average width of the openings exposed on the second surface.

7. The lighting-emitting device of claim 4, wherein a portion of the openings exposed on the second surface has a depth h1, another portion of the openings exposed on the second surface has a depth h2, and h1 is smaller than h2.

8. The lighting-emitting device of claim 1, further comprising a mesa exposing the active layer and the first semiconductor layer.

9. The lighting-emitting device of claim 1, further comprising:

a second semiconductor layer; and

a first electrode formed on the second semiconductor layer.

10. The lighting-emitting device of claim 9, further comprising a transparent conductive oxide layer formed between the first electrode and the second semiconductor layer.

11. The lighting-emitting device of claim 1, wherein the active layer is narrower than the first semiconductor layer.

12. The lighting-emitting device of claim 1, wherein the first surface comprises a textured surface, the first openings are exposed on the textured surface.