Series connected segmented LED

• US 9,123,853 B2
• Filed: 08/05/2013
• Issued: 09/01/2015
• Est. Priority Date: 11/09/2011
• Status: Active Grant

• Current Assignee: Alpad Corporation
• Original Assignee: Manutius IP, Inc.
• Inventors: Lester, Steven D., Chuang, Chih-Wei
• Primary Examiner(s): STARK, JARRETT J
• Application Number:
  US13/959,313
• Publication Number:
  US 20130313519A1
• Time in Patent Office: 757 Days
• Field of Search: 438/29
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• 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 source and method for making the same are disclosed. The light source includes a conducting substrate, and a light emitting structure that is divided into segments. The light emitting structure includes a first layer of semiconductor material of a first conductivity type deposited on the substrate, an active layer overlying the first layer, and a second layer of semiconductor material of an opposite conductivity type from the first conductivity type overlying the active layer. A barrier divides the light emitting structure into first and second segments that are electrically isolated from one another. A serial connection electrode connects the first layer in the first segment to the second layer in the second segment. A power contact is electrically connected to the second layer in the first segment, and a second power contact electrically connected to the first layer in the second segment.

Claims

1. A method of fabricating a light emitting device, comprising:

depositing a light emitting structure on a first substrate, the light emitting structure comprising;

a first semiconductor layer formed on the first substrate,

an active layer formed on the first semiconductor layer, and

a second semiconductor layer formed on the active layer;

patterning a metallic mirror layer over the second semiconductor layer and in electrical contact therewith;

forming a barrier layer directly on the mirror layer and directly on the second semiconductor layer;

forming a metallic bonding layer above the barrier layer;

bonding the metallic bonding layer to a second substrate, wherein the second substrate comprises;

a region of a first conductivity type,

a first isolation region of a second conductivity type, and

a second isolation region of the second conductivity type;

removing the first substrate;

etching the light emitting structure to form a trench that exposes an upper surface of the barrier layer, wherein the trench divides the light emitting structure into first and second segments that are electrically isolated from one another at least by the first and second isolation regions; and

forming a connection electrode that contacts at least a portion of an upper surface of the barrier layer in the first segment and connects the barrier layer in the first segment to the first semiconductor layer in the second segment.

2. The method of claim 1, further comprising:

depositing a first power contact electrically connected to the second semiconductor layer in the first segment; and

depositing a second power contact electrically connected to the first semiconductor layer in the second segment, wherein the first and second segments generate light when a potential difference is created between the first and second power contacts.

3. The method of claim 1, wherein the first and second isolation regions isolate the mirror from the second substrate.

4. The method of claim 1, wherein the first substrate comprises silicon.

5. The method of claim 1, wherein the second substrate comprises silicon.

6. The method of claim 1, wherein the first semiconductor layer comprises an n-type GaN family member.

7. The method of claim 1 wherein the metallic bonding layer is formed directly on the barrier layer.

8. The method of claim 1 wherein the second substrate is a p-type substrate, and wherein the first and second isolation regions are n-type wells.

9. The method of claim 1, wherein the first isolation region is positioned with correspondence to the first segment, and the second isolation region is positioned with correspondence to the second segment.

10. The method of claim 9 further comprising:

forming a second metallic bonding layer over the first isolation region and the second isolation region prior to the bonding step, wherein the second metallic bonding layer over the first isolation region is used to bond the first isolation region to the corresponding first segment, and the second metallic bonding layer over the second isolation region is used to bond the second isolation region to the corresponding second segment.

11. The method of claim 10 wherein the second metallic bonding layer formed over the first isolation region is isolated from the second metallic bonding layer formed over the second isolation region.

12. The method of claim 1 further comprising:

forming an insulation layer in at least a portion of the trench, wherein the connection electrode is formed on at least a portion of the insulation layer.

13. The method of claim 12 wherein the insulation layer is formed from silicon nitride.

14. The method of claim 1 wherein the first conductivity type is a p-type, and the second conductivity type is n-type.