Light emitting device and fabrication method thereof

• US 8,053,789 B2
• Filed: 12/12/2007
• Issued: 11/08/2011
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: Kim, Chang Yeon, Yoon, Yeo Jin
• Primary Examiner(s): Nguyen; Khiem D
• Application Number:
  US12/518,846
• Publication Number:
  US 20100012969A1
• Time in Patent Office: 1,427 Days
• Field of Search: 438 22- 47, 257/82, 257/86, 257/90, 257/98, 257/E33.001
• US Class Current: 257/82
• CPC Class Codes: H01L 21/28 Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268 etching for patterning the electrodes H01L21/311, H01L21/3213; multistep manufacturing processes for data storage electrodes H01L29/4011
• CPC Class Codes: H01L 21/306 Chemical or electrical treatment, e.g. electrolytic etching to form insulating layers H01L21/31
• 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 33/60 Reflective elements

Abstract

There is provided a method of fabricating a vertical light emitting diode. The method comprises the steps of: growing a low doped first conductive semiconductor layer on a sacrificial substrate; forming an aluminum layer on the low doped first conductive semiconductor layer; forming an AAO layer having a large number of holes formed therein by performing anodizing treatment of the aluminum layer; etching and patterning the low doped first conductive semiconductor layer using the aluminum layer with a large number of the holes as a shadow mask to expose a portion of the low doped first conductive semiconductor layer, thereby forming a large number of grooves; removing the aluminum layer remaining on the low doped first conductive semiconductor layer; sequentially forming a high doped first conductive semiconductor layer, an active layer and a second conductive semiconductor layer on the low doped first conductive semiconductor layer with a large number of the grooves; forming a metal reflective layer and a conductive substrate on the second conductive semiconductor layer; separating the sacrificial substrate; and forming an electrode pad on the other surface of the low doped first conductive semiconductor layer, the electrode pad being filled in a large number of the grooves to be in ohmic contact with the high doped first conductive semiconductor layer.

Claims

1. A light emitting diode (LED), comprising:

a first semiconductor layer having a plurality of grooves formed therein;

second semiconductor layer disposed on one surface of the first semiconductor layer, the second semiconductor layer being exposed by the plurality of the grooves of the first semiconductor layer;

an active layer and a third semiconductor layer, disposed on one surface of the second semiconductor layer;

a reflective layer and a conductive substrate, disposed on one surface of the third semiconductor layer the reflective layer disposed between the third semiconductor layer and the conductive substrate; and

a first electrode pad disposed on the other surface of the first semiconductor layer, the first electrode pad being filled in at least a portion of the grooves.

2. The LED of claim 1, wherein the doping concentration of dopant in the second semiconductor layer is 5 to 9×

10¹⁸/cm³, and the doping concentration of dopant in the first semiconductor layer is below 5×

10¹⁸/cm³.

3. The LED of claim 1, wherein the first semiconductor layer has the plurality of the grooves formed through etching using an anodic aluminum oxide (AAO) layer as a shadow mask.

4. The LED of claim 2, wherein the first and second semiconductor layers comprise the same dopants.

5. The LED of claim 4, wherein the first and second semiconductor layers are n-type layers, and the third semiconductor layer is a p-type layer.

6. The LED of claim 1, further comprising a second electrode pad, the second electrode pad being disposed between the third semiconductor layer and the reflective layer, and the second electrode pad facing the first electrode pad.

7. The LED of claim 1, wherein the plurality of grooves each comprise a width of 500 nm or less.