Light-emitting device having a trench in a semiconductor layer

• US 8,872,204 B2
• Filed: 06/02/2011
• Issued: 10/28/2014
• Est. Priority Date: 11/23/2007
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Yang, Yu-Chen, Jou, Li-Ping, Yeh, Jui-Hung, Shen, Chien-Fu
• Primary Examiner(s): Tran, Long K
• Assistant Examiner(s): KLEIN, JORDAN M
• Application Number:
  US13/152,026
• Publication Number:
  US 20110227120A1
• Time in Patent Office: 1,244 Days
• Field of Search: 257/E33.005, 257/E33.006, 257/E33.011, 257/98, 257/E33.065, 257/E33.074
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/641 characterized by the materials

Abstract

A light-emitting device comprises a substrate, an epitaxial structure formed on the substrate including a first semiconductor layer, a second semiconductor layer, and a light-emitting layer formed between the first semiconductor layer and the second semiconductor layer. A trench is formed in the epitaxial structure to expose a part of side surface of the epitaxial structure and a part of surface of the first semiconductor layer, so that a first conductive structure is formed on the part of surface of the first semiconductor layer in the trench, and a second conductive structure is formed on the second semiconductor layer. The first conductive structure includes a first electrode and a first pad electrically contacted with each other. The second conductive structure includes a second electrode and a second pad electrically contacted with each other. Furthermore, the area of at least one of the first pad and the second pad is between 1.5×10⁴ μm² and 6.2×10⁴ μm².

Claims

1. A light-emitting device comprising:

a substrate;

an adhesive layer on the substrate;

a reflection layer on the adhesive layer;

a second semiconductor layer on the reflection layer;

a light-emitting layer on the second semiconductor layer;

a first semiconductor layer on the light-emitting layer, wherein a thickness of the first semiconductor layer is H;

a plurality of trenches through the first semiconductor layer, wherein a depth of one of the plurality of trenches is h; and

a first conductive structure on the first semiconductor layer;

wherein the depth of the trench h is greater than ⅓

of the thickness of the first semiconductor layer H;

wherein the first conductive structure comprises a first electrode encompassing an edge region of the light-emitting device, and

wherein a total area of all trenches in the first semiconductor layer is not greater than 50% of an area of a top surface of the first semiconductor layer.

2. The light-emitting device according to claim 1, wherein the at least one trench is formed by removing a portion of the top surface of the first semiconductor layer.

3. The light-emitting device according to claim 1, wherein the depth of the trench h is not greater than the thickness of the first semiconductor layer H.

4. The light-emitting device according to claim 1, wherein the first conductive structure comprises a first pad connecting with the first electrode.

5. The light-emitting device according to claim 4, wherein an area of the first pad is between 1.5×

10⁴ μ

m² and 6.2×

10⁴ μ

m².

6. The light-emitting device according to claim 4, wherein the first conductive structure further comprises a second pad.

7. The light-emitting device according to claim 1, wherein the plurality of trenches forms a two-dimensional array.

8. The light-emitting device according to claim 1, wherein a top view of one of the plurality of trenches comprises a circle.

9. A light-emitting device comprising:

a substrate;

a second semiconductor layer on the substrate;

a light-emitting layer on the second semiconductor layer;

a first semiconductor layer on the light-emitting layer;

a plurality of trenches in the first semiconductor layer; and

a first conductive structure comprising a plurality of first electrodes and a first pad on the first semiconductor layer;

wherein a depth of one of the plurality of trenches is greater than one-third of a thickness of the first semiconductor layer but less than the thickness of the first semiconductor layer;

wherein the plurality of trenches is formed between two of the plurality of first electrodes, and

wherein a total area of all trenches in the first semiconductor layer is not greater than 50% of an area of a top surface of the first semiconductor layer.

10. The light-emitting device according to claim 9, further comprising another trench in the first semiconductor layer, wherein the another trench is formed between two of the plurality of first electrodes.

11. The light-emitting device according to claim 9, wherein a top view one of the plurality of trenches comprises a stripe.

12. The light-emitting device according to claim 11, wherein the stripe comprises a round corner.

13. The light-emitting device according to claim 9, wherein an area of the first pad is between 1.5×

10⁴ μ

m² and 6.2×

10⁴ μ

m².

14. The light-emitting device according to claim 9, wherein two of the plurality of first electrodes encompass an edge region of the light-emitting device, and another two of the plurality of first electrodes extend through a central region of the top surface of the first semiconductor layer.

15. The light-emitting device according to claim 9, wherein the first conductive structure further comprises a second pad on the first semiconductor layer.