Light emitting structure including high-al content MQWH

• US 8,154,009 B1
• Filed: 05/04/2009
• Issued: 04/10/2012
• Est. Priority Date: 11/14/2005
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Wong, William S., Kneissl, Michael A., Yang, Zhihong, Teepe, Mark, Knollenberg, Cliff
• Primary Examiner(s): Reames, Matthew
• Application Number:
  US12/435,342
• Time in Patent Office: 1,072 Days
• Field of Search: 257/13, 257/E33.008
• US Class Current: 257/13
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 29/155 Comprising only semiconductor materials H01L29/154 takes precedence
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/205 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 5/0213 Sapphire, quartz or diamond based substrates
• CPC Class Codes: H01S 5/0216 using an intermediate compound, e.g. a glue or solder
• CPC Class Codes: H01S 5/0217 Removal of the substrate
• CPC Class Codes: H01S 5/0234 Up-side down mountings, e.g. Flip-chip, epi-side down mountings or junction down mountings
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

A GaN/AlN superlattice is formed over a GaN/sapphire template structure, serving in part as a strain relief layer for growth of subsequent layers (e.g., deep UV light emitting diodes). The GaN/AlN superlattice mitigates the strain between a GaN/sapphire template and a multiple quantum well heterostructure active region, allowing the use of high Al mole fraction in the active region, and therefore emission in the deep UV wavelengths.

Claims

1. A semiconductor light emitting diode structure of a type formed on a substrate, wherein said substrate is removed and said semiconductor light emitting diode is bonded to a heat sink structure, comprising:

first and second index guiding layers;

a multiple quantum well heterostructure of a composition including at least 25% aluminum, formed between said first and second index guiding layers; and

a heat sink to which said first and second index guiding layers having said multiple quantum well heterostructure therebetween are bonded;

wherein said multiple quantum well heterostructure is substantially free from structural cracks;

wherein said structure is capable of emitting light at a wavelength of approximately 325 nm.

2. A semiconductor light emitting diode structure of a type formed on a substrate, wherein said substrate is removed and said semiconductor light emitting diode is bonded to a heat sink structure, comprising:

first and second index guiding layers;

a multiple quantum well heterostructure of composition In_wGa_xAl_yN_z, where w+x+y+z=1, and where y≧

0.35, formed between said first and second index guiding layers; and

a heat sink to which said first and second index guiding layers having said multiple quantum well heterostructure therebetween are bonded;

wherein said multiple quantum well heterostructure is substantially free from structural cracks;

wherein said structure is capable of emitting light at a wavelength of approximately 325 nm.

3. A semiconductor light emitting diode structure of a type formed on a substrate, wherein said substrate is removed and said semiconductor light emitting diode is bonded to a heat sink structure, comprising:

first and second index guiding layers; and

a multiple quantum well heterostructure of a composition including at least 25% aluminum, formed between said first and second index guiding layers;

wherein said multiple quantum well heterostructure is substantially free from structural cracks; and

wherein said structure is capable of emitting light at a wavelength of approximately 325 nm.