Method of forming a light emitting diode structure and a light diode structure

• US 10,186,635 B2
• Filed: 10/20/2015
• Issued: 01/22/2019
• Est. Priority Date: 05/18/2010
• Status: Active Grant

• Current Assignee: Agency For Science Technology and Research (Government of Singapore)
• Original Assignee: Agency For Science Technology and Research (Government of Singapore)
• Inventors: Sudhiranjan, Tripathy, Vivian Kaixin, Lin, Siew Lang, Teo, Surani Bin, Dolmanan
• Primary Examiner(s): Wilson, Scott R
• Application Number:
  US14/918,342
• Publication Number:
  US 20160149084A1
• Time in Patent Office: 1,190 Days
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials

Abstract

A method of forming a vertical III-nitride based light emitting diode structure 5 and a vertical III-nitride based light emitting diode structure can be provided. The method comprises forming a III-nitride based light emitting structure on a silicon-oninsulator (SOI) substrate; forming a metal-based electrode structure on the III-nitride based light emitting structure; and removing the SOI substrate by a layer transfer process such that the metal-based electrode structure functions as a metal-based 10 substrate of the light emitting structure.

Claims

1. A vertical III-nitride based light emitting diode structure, the structure comprising:

a metal-based substrate; and

a III-nitride based light emitting structure for light emission formed on the metal-based substrate, the III-nitride based light emitting structure comprising a light-generating layer comprising a plurality of III-nitride heterostructures,

wherein a Group III metal content in the light-generating layer is inhomogeneously formed in response to creation of a patterned silicon-on-insulator (SOI) substrate comprising one or more silicon overlayers having a thickness ranging from about 10 nm to about 300 nm and a patterned buried oxide or silicon dioxide layer having a thickness ranging from about 60 to about 400 nm for modulating light emission of the vertical III-nitride based light emitting diode structure.

2. The structure as claimed in claim 1, further comprising a metal seed layer formed between the III-nitride based light emitting structure and the metal-based substrate for facilitating layer transfer of the III-nitride based light emitting diode structure from the patterned silicon-on-insulator (SOI) substrate.

3. The structure as claimed in claim 2, wherein the seed layer comprises nickel having a thickness ranging from about 100 nm to about 1000 nm.

4. The structure as claimed in claim 2, wherein the seed layer is electroplated to the metal-based substrate.

5. The structure as claimed in claim 1, further comprising a reflective mirror layer capable of functioning as a p-type contact electrode, the mirror layer formed between the metal-based substrate and the III-nitride based light emitting structure.

6. The structure as claimed in claim 5, wherein the reflective mirror layer comprises a plurality of layers selected from a group of material consisting of nickel, gold, platinum, silver, palladium and ruthenium.

7. The structure as claimed in claim 1, further comprising photonic crystal (PhC) structures formed on an n-doped III-nitride layer of the III-nitride based light emitting diode structure, the PhC structures having lateral and vertical dimensions of less than about 400 nm.

8. The structure as claimed in claim 1, further comprising photonic crystal (PhC) structures formed on an n-doped III-nitride layer of the III-nitride based light emitting diode structure, the PhC structures comprising periodic patterns of structures selected from a group consisting of nanopillars, nanoholes and nanopyramid structures.

9. The structure as claimed in claim 1, further comprising an n-type contact electrode structure formed on the III-nitride based light emitting structure.

10. The structure as claimed in claim 9, wherein the n-type contact electrode structure comprises a plurality of layers selected from a group of material consisting of titanium, aluminium, gold, chromium and nickel.

11. The structure as claimed in claim 1, wherein the plurality of heterostructures of the light-generating layer comprise a plurality of InGaN/GaN quantum wells, and wherein an indium content in the plurality of InGaN/GaN quantum wells is inhomogeneous across the light-generating layer for modulating light emission of the vertical III-nitride based light emitting diode structure.

12. A vertical III-nitride based light emitting diode structure, the structure comprising,

a patterned buried oxide layer of a silicon-on-insulator (SOI) substrate;

a III-nitride based light emitting structure for light emission formed on the patterned SOI substrate, the III-nitride based light emitting structure comprising an active layer comprising a plurality of III-nitride heterostructures,

wherein a Group III metal content in the active layer of the III-nitride based light emitting structure is inhomogeneously formed in response to creation of the patterned SOI substrate comprising one or more silicon overlayers having a thickness ranging from about 10 nm to about 300 nm and the patterned buried oxide layer having a thickness ranging from about 60 to about 400 nm for modulating an emission of the light emitting diode structure.

13. The structure as claimed in claim 12, wherein the III-nitride based light emitting structure comprises one or more nitride-based buffer layers formed directly on the patterned SOI substrate.

14. The structure as claimed in claim 12, wherein the plurality of heterostructures of the active layer comprise a plurality of InGaN/GaN quantum wells, and wherein an indium content in the plurality of InGaN/GaN quantum wells is inhomogeneous across the active layer for modulating light emission of the vertical III-nitride based light emitting diode structure.