Light emitting diode having distributed bragg reflectors (DBR) and manufacturing method thereof

• US 9,705,045 B2
• Filed: 02/17/2016
• Issued: 07/11/2017
• Est. Priority Date: 02/17/2015
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Genesis Photonics Inc.
• Inventors: Huang, Yi-Ru, Huang, Kuan-Chieh, Shen, Chih-Ming, Chuang, Tung-Lin, Mai, Hung-Chuan, Huang, Jing-En, Ting, Shao-Ying
• Primary Examiner(s): Dickey, Thomas L
• Assistant Examiner(s): Yi, Changhyun
• Application Number:
  US15/045,488
• Publication Number:
  US 20160240744A1
• Time in Patent Office: 510 Days
• Field of Search: 257 98
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/36 characterised by the electrodes
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light emitting diode (LED) having distributed Bragg reflector (DBR) and a manufacturing method thereof are provided. The distributed Bragg reflector is used as a reflective element for reflecting the light generated by the light emitting layer to an ideal direction of light output. The distributed Bragg reflector has a plurality of through holes, such that the metal layer and the transparent conductive layer disposed on two sides of the distributed Bragg reflector may contact each other to conduct the current. Due to the distribution properties of the through holes, the current may be more uniformly diffused, and the light may be more uniformly emitted from the light emitting layer.

Claims

1. A light emitting diode (LED) having distributed Bragg reflector, comprising:

an epitaxial layer having a first semiconductor layer, a light emitting layer and a second semiconductor layer, wherein the light emitting layer is interposed between the first semiconductor layer and the second semiconductor layer;

a transparent conductive layer disposed on the second semiconductor layer;

a Bragg reflective layer disposed on the transparent conductive layer and having a plurality of first through holes penetrating through the Bragg reflective layer;

a first electrode electrically connected to the first semiconductor layer;

a second electrode electrically connected to the transparent conductive layer; and

a plurality of intervals in adjoining through holes of the plurality of first through holes and a plurality of distances between the plurality of first through holes and the second electrode, wherein the plurality of intervals gradually decrease as the plurality of distances gradually increase.

2. The LED having distributed Bragg reflector according to claim 1, further comprising:

a metal layer disposed on the Bragg reflective layer; and

an insulating layer disposed on the metal layer and having a second through hole exposing a part of the metal layer, wherein the second electrode is disposed on the insulating layer and electrically connected to the metal layer via the second through hole.

3. The LED having distributed Bragg reflector according to claim 1, further comprising a plurality of current blocking layers disposed on the second semiconductor layer and corresponding to the plurality of first through holes.

4. An LED having distributed Bragg reflector, comprising:

an epitaxial layer having a first semiconductor layer, a light emitting layer and a second semiconductor layer;

a plurality of current blocking layers disposed on the second semiconductor layer;

a transparent conductive layer disposed on the plurality of current blocking layers and the second semiconductor layer;

a Bragg reflective layer disposed on the transparent conductive layer and having a plurality of first through holes penetrating the Bragg reflective layer and corresponding to the plurality of current blocking layers to expose a part of the transparent conductive layer;

a first electrode electrically connected to the first semiconductor layer;

a second electrode disposed on the Bragg reflective layer and electrically connected to the transparent conductive layer via the plurality of first through holes; and

a plurality of intervals in adjoining through holes of the plurality of first through holes and a plurality of distances between the plurality of first through holes and the second electrode, wherein the plurality of intervals gradually decrease as the plurality of distances gradually increase.