LIGHT EMITTING DEVICE AND FABRICATION METHOD THEREOF

• US 20120241787A1
• Filed: 09/16/2011
• Published: 09/27/2012
• 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: YOON, Yeo Jin, KIM, Chang Yeon
• Granted Patent: US 8,546,819 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• 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

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

Claims

1. A method of fabricating a patterned substrate for fabricating a light emitting diode (LED), comprising:

forming an aluminum layer on a substrate;

forming an anodic aluminum oxide (AAO) layer having a large number of holes formed therein by performing an anodizing treatment of the aluminum layer;

partially etching a surface of the substrate using the aluminum layer with the large number of the holes as a shadow mask, thereby forming patterns; and

removing the aluminum layer from the substrate.

2. The method of claim 1, wherein the substrate is any one of a sapphire substrate, a spinel substrate, a Si substrate, a SiC substrate, a ZnO substrate, a GaAs substrate and a GaN substrate.

3. A method of fabricating a vertical light emitting diode (LED), comprising:

forming a low doped first conductive semiconductor layer on a sacrificial substrate;

forming an aluminum layer on a surface of the low doped first conductive semiconductor layer;

forming an anodic aluminum oxide (AAO) layer having a large number of holes formed therein by performing an anodizing treatment of the aluminum layer;

etching and patterning the low doped first conductive semiconductor layer using the aluminum layer with the 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 from 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 the large number of the grooves;

forming a metal reflective layer and a conductive substrate on the second conductive semiconductor layer;

separating the sacrificial substrate from the low doped first conductive semiconductor layer; 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.

4. The method of claim 3, wherein the doping concentration of dopant in the high doped first conductive semiconductor layer is 5 to 9.times.10.sup.18/cm.sup.3, and the doping concentration of dopant in the low doped first conductive semiconductor layer is below 5×

10¹⁸/cm³.

5. A method of fabricating a light emitting device having a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer interposed therebetween formed on a substrate, the method comprising:

forming the first conductive semiconductor layer on the substrate;

forming an aluminum layer on the first conductive semiconductor layer;

forming an anodic aluminum oxide (AAO) layer having a large number of holes formed therein by performing an anodizing treatment of the aluminum layer;

etching and patterning the first conductive semiconductor layer using the aluminum layer with the large number of the holes as a shadow mask so that a portion of the first conductive semiconductor layer is etched;

removing the aluminum layer from the first conductive semiconductor layer;

forming the first conductive semiconductor layer on the etched first conductive semiconductor layer; and

forming the active layer and the second conductive semiconductor layer on the first is conductive semiconductor layer.

6. A light emitting device, comprising:

a substrate;

a first conductive semiconductor layer disposed on the substrate;

an active layer disposed on the first conductive semiconductor layer; and

s a second conductive semiconductor layer disposed on the active layer, wherein the first conductive semiconductor layer comprises a large number of scattering centers formed of an air layer.

7. The light emitting device of claim 6, wherein the first conductive semiconductor layer comprises a first layer having the large number of the scattering centers formed of the air layer and a second layer formed on the first layer.

8. The light emitting device of claim 6, wherein the large number of the scattering centers formed of the air layer are formed in the first conductive semiconductor layer through etching using an anodic aluminum oxide (AAO) layer as a shadow mask.

9. A method of forming an anodic aluminum oxide (AAO) shadow mask for etching a semiconductor layer, comprising:

depositing an aluminum metal in a thickness on the semiconductor layer to form an aluminum layer having an exposed surface;

depositing the aluminum layer in a first acid solution and applying a bias to the aluminum layer to oxidize inward from the exposed surface of the aluminum to form a large number of oxidized hollows inward from the exposed surface;

applying a second acid solution to etch away the oxidized hollows in the aluminum layer to form a large number of holes in the aluminum layer extending to the semiconductor layer to form the AAO shadow mask; and

etching the semiconductor layer in the large number of holes in the aluminum layer to form a pattern of holes in the semiconductor layer, wherein the holes have openings of 500 nm or less.