LED STRUCTURE AND METHOD FOR MANUFACTURING THEREOF

• US 20130026491A1
• Filed: 09/23/2011
• Published: 01/31/2013
• Est. Priority Date: 07/27/2011
• Status: Abandoned Application

• Current Assignee: Lextar Electronics Corporation (Ennostar, Inc.)
• Original Assignee: Lextar Electronics Corporation (Ennostar, Inc.)
• Inventors: CHEN, CHENG-HUNG, HSIA, DER-LIN, HOU, CHIA-HUNG
• Application Number:
  US13/241,563
• Publication Number:
  US 20130026491A1
• Time in Patent Office: Days
• US Class Current: 257/77
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

The present invention discloses a LED structure and a method for manufacturing the LED structure. The LED structure includes a substrate, a reflection layer, a first conducting layer, a light emitting layer, and a second conducting layer. The substrate has a plurality of grooves, and the reflection layer is disposed inside the plurality of grooves. The reflection layer is formed as a reflection block inside each of the grooves. The first conducting layer is disposed on the substrate, that is, the reflection layer is disposed between the first conducting layer and the substrate. The light emitting layer and the second conducting layer are sequentially disposed on the first conducting layer. The light emitting layer generates light when a current pass through the light emitting layer. Accordingly, the light generated by the light emitting layer can be emitted to the same side of the LED structure.

Claims

1. A LED structure, comprising:

a substrate having a plurality of grooves;

a reflection layer, disposed inside the grooves, being formed as a plurality of reflection blocks, each reflection block being disposed inside one of the grooves;

a first conducting layer being disposed on the substrate and covering the grooves;

a light emitting layer being disposed on the first conducting layer; and

a second conducting layer being disposed on the light emitting layer;

wherein the light emitting layer generates light when a current pass through the first conducting layer, the light emitting layer, and the second conducting layer.

2. The LED structure according to claim 1, wherein a plurality of air gaps are formed between the reflection layer and the first conducting layer, each air gap is sandwiched between the first conducting layer and one of the reflection blocks within the corresponding groove.

3. The LED structure according to claim 2, wherein each air gap has a depth-width ratio, the depth-width ratio is modulated according to the ratio of V semiconductor material and III semiconductor material while manufacturing the first conducting layer during an epitaxy process.

4. The LED structure according to claim 2, wherein the ratio of V semiconductor material and III semiconductor material of the first conducting layer is controlled beyond 2000.

5. The LED structure according to claim 4, wherein the ratio of V semiconductor material and III semiconductor material of the first conducting layer is controlled within the range of 2000˜

3000.

6. The LED structure according to claim 1, wherein no air gaps is formed between the reflection layer and the first conducting layer, when the ratio of V semiconductor material and III semiconductor material of the first conducting layer is controlled within the range of 0˜

2000.

7. The LED structure according to claim 1, wherein the grooves are formed on an upper surface of the substrate, and the upper surface and the reflection layer disposed inside the grooves are in coplanar.

8. The LED structure according to claim 1, wherein the material of the substrate is selected from the group consisting of silicon, gallium nitride, aluminium nitride, sapphire, spinel, silicon carbide, gallium arsenide, aluminium oxide, lithium gallium oxide, lithium aluminium oxide, and magnesium aluminum oxide.

9. A method for manufacturing a LED structure, comprising the following steps:

disposing a patterned photoresist layer on a substrate;

performing a photolithography process for etching a plurality of portions of the substrate which are not covered by the patterned photoresist layer, and forming a plurality of grooves of the substrate, the locations of the grooves are corresponded to the portions;

forming a reflection layer on the patterned photoresist layer and the grooves, and the reflection layer being formed as one of a plurality of reflection blocks inside each groove;

removing the patterned photoresist layer;

forming a first conducting layer on the substrate, and the first conducting layer covering the grooves;

forming a light emitting layer on the first conducting layer; and

forming a second conducting layer on the light emitting layer;

wherein the light emitting layer generates light when a current pass through the first conducting layer, the light emitting layer, and the second conducting layer.

10. The method according to claim 9, wherein a plurality of air gaps are formed between the reflection layer and the first conducting layer, each air gap is sandwiched between the first conducting layer and one of the reflection blocks within the corresponding groove.

11. The method according to claim 10, wherein each air gap has a depth-width ratio, the depth-width ratio is modulated according to the ratio of V semiconductor material and III semiconductor material while manufacturing the first conducting layer during an epitaxy process.

12. The method according to claim 10, wherein the ratio of V semiconductor material and III semiconductor material of the first conducting layer is controlled beyond 2000.

13. The method according to claim 12, wherein the ratio of V semiconductor material and III semiconductor material of the first conducting layer is controlled within the range of 2000˜

3000.

14. The method according to claim 9, wherein no air gaps is formed between the reflection layer and the first conducting layer, when the ratio of V semiconductor material and III semiconductor material of the first conducting layer is controlled within the range of 0˜

2000.

15. The method according to claim 9, wherein the grooves are formed on an upper surface of the substrate, and the upper surface and the reflection layer disposed inside the grooves are in coplanar.

16. The method according to claim 9, wherein the material of the substrate is selected from the group consisting of silicon, gallium nitride, aluminium nitride, sapphire, spinel, silicon carbide, gallium arsenide, aluminium oxide, lithium gallium oxide, lithium aluminium oxide, and magnesium aluminum oxide.