High output light emitting diode and method for fabricating the same

• US 7,939,841 B2
• Filed: 12/28/2005
• Issued: 05/10/2011
• Est. Priority Date: 12/31/2004
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Hyun Jae, Ha, Jun Seok
• Primary Examiner(s): SMITH, BRADLEY
• Application Number:
  US11/318,505
• Publication Number:
  US 20060145174A1
• Time in Patent Office: 1,959 Days
• Field of Search: 257 79-103, 257/E33.068
• US Class Current: 257/98
• 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

A high output light emitting diode (LED) and a method for fabricating the LED is disclosed. The LED includes a sidewall or surface that is inclined. A reflective film is formed on the inclined sidewall or surface to allow light to reflect from the reflective film and to emit the light upward or in a favorable direction with respect to the device, thereby being configured and enabled to improve a light output of the LED and dispense with an additional passivation process.

Claims

1. A light emitting device having a vertical topology structure comprising:

a light emitting diode (LED) structure having a first surface, a second surface, inclined sidewalls and a first side surface, a second side surface, a third side surface, and a fourth side surface, the LED structure comprising a first-type semiconductor layer, an active layer and a second-type semiconductor layer, wherein the inclined sidewalls have grooves continuously and straightly extended along said sidewalls of said layers and are configured to increase the total light emitting area thereof, wherein grooves are respectively formed on the first side, the second side, the third side, and the fourth side surfaces, and each groove has substantially the same depth;

a first electrode over the first surface of the LED structure;

a second electrode over the second surface of the LED structure, wherein the first electrode and second electrode are located over the opposite surfaces of the LED structure, respectively;

a reflective film disposed over the inclined sidewalls of the LED structure, the reflective film comprising an anti-reflection layer and a reflection layer, wherein the reflective film is configured to reflect light emitted from the active layer generally back through the first surface of the LED structure and also configured to serve as a passivation layer.

2. The light emitting device as defined in claim 1, wherein each of the inclined sidewalls defines an angle having a range of 30-70 degrees.

3. The light emitting device as defined in claim 1, wherein each of the inclined sidewalls has substantially the same inclination angle.

4. The light emitting device as defined in claim 1, wherein the grooves comprise a planar portion and/or a curved portion.

5. The light emitting device as defined in claim 1, wherein a horizontal cross-sectional area of the first semiconductor layer is greater than that of the second semiconductor layer.

6. The light emitting device as defined in claim 1, wherein each of the inclined sidewalls has a reversed slope.

7. The light emitting device as defined in claim 1, wherein the grooves are formed by a partially removed portion of the LED structure.