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Defect Reduction of Non-Polar and Semi-Polar III-Nitrides

Technology Benefits

Reduced dislocation density in GaN films Reduced stacking fault density Eliminates polarization fields Improved performance in GaN-based devices (longer lifetimes, less leakage current, more efficient doping and higher output efficiency)

Technology Application

Non-polar and semi-polar GaN films GaN-based devices  This technology is available for a non-exclusive license. See below for a selection of the patents and patent applications related to this invention. Please inquire for full patent portfolio status.

Detailed Technology Description

Researchers at the University of California, Santa Barbara have successfully developed sidewall lateral epitaxial overgrowth (SLEO) of non-polar a-plane and m-plane GaN. By using single step lateral epitaxial overgrowth, dislocation densities can be reduced and stacking faults are localized only on the nitrogen faces. Dislocation densities can be reduced down to even lower values by eliminating defects not only in the overgrown regions but also in the window regions. Also, by favoring gallium (Ga) face growth and limiting nitrogen (N) face growth stacking fault densities can be made orders of magnitude lower.  The present invention also takes advantage of the orientation of non-polar III-Nitrides to eliminate polarization fields. As a result, with the material produced by utilizing this invention, device improvements such as longer lifetimes, less leakage current, more efficient doping and higher output efficiency are possible. In addition, a thick non-polar and semi-polar nitride free-standing substrate, which is needed to solve the lattice mismatch issue, can be produced over this excellent material.

Supplementary Information

Patent Number: US7361576B2
Application Number: US2006444084A
Inventor: Imer, Bilge M. | Speck, James S. | DenBaars, Steven P.
Priority Date: 31 May 2005
Priority Number: US7361576B2
Application Date: 31 May 2006
Publication Date: 22 Apr 2008
IPC Current: H01L002120 | H01L002136
US Class: 438479 | 257E21097 | 257E21131 | 257E21132 | 257E21566 | 438041 | 438481
Assignee Applicant: The Regents of the University of California | Japan Science and Technology Agencyitama
Title: Defect reduction of non-polar and semi-polar III-Nitrides with sidewall lateral epitaxial overgrowth (SLEO)
Usefulness: Defect reduction of non-polar and semi-polar III-Nitrides with sidewall lateral epitaxial overgrowth (SLEO)
Summary: For reducing threading dislocation densities in non-polar and semi-polar III-Nitride material useful to form device, wafer, substrate or template (claimed).
Novelty: Reducing threading dislocation densities in non-polar and semi-polar-nitride material used to form e.g. film involves performing lateral epitaxial overgrowth of the material from sidewalls of etched template material through patterned mask

Industry

Optics

Sub Category

LED/OLED

Application No.

7361576

Others

Background

It is relatively easy to grow c-plane GaN due to its large growth window (pressure, temperature and precursor flows) and its stability. However, as a result of c-plane growth, each material layer suffers from separation of electrons and holes to opposite faces of the layers. Furthermore, strain at the interfaces between adjacent layers gives rise to piezoelectric polarization, causing further charge separation. Such polarization effects decrease the likelihood of electrons and holes recombining, causing the device to perform poorly.  Another reason why GaN materials perform poorly is the presence of defects due to lack of a lattice matched substrate. There is an ever-increasing effort to reduce the dislocation density in GaN films in order to improve device performance.

Additional Technologies by these Inventors

• Reduced Dislocation Density of Non-Polar GaN Grown by Hydride Vapor Phase Epitaxy
• Growth of Planar, Non-Polar, A-Plane GaN by Hydride Vapor Phase Epitaxy
• Nonpolar (Al, B, In, Ga)N Quantum Well Design
• Cleaved Facet Edge-Emitting Laser Diodes Grown on Semipolar GaN
• Etching Technique for the Fabrication of Thin (Al, In, Ga)N Layers
• Enhancing Growth of Semipolar (Al,In,Ga,B)N Films via MOCVD
• GaN-Based Thermoelectric Device for Micro-Power Generation
• Growth of High-Quality, Thick, Non-Polar M-Plane GaN Films
• Growth of Planar Semi-Polar Gallium Nitride
• MOCVD Growth of Planar Non-Polar M-Plane Gallium Nitride
• Lateral Growth Method for Defect Reduction of Semipolar Nitride Films
• Low Temperature Deposition of Magnesium Doped Nitride Films
• Improved Manufacturing of Solid State Lasers via Patterning of Photonic Crystals
• Single or Multi-Color High Efficiency LED by Growth Over a Patterned Substrate
• High Efficiency LED with Optimized Photonic Crystal Extractor
• Packaging Technique for the Fabrication of Polarized Light Emitting Diodes
• LED Device Structures with Minimized Light Re-Absorption
• (In,Ga,Al)N Optoelectronic Devices with Thicker Active Layers for Improved Performance
• Oxyfluoride Phosphors for Use in White Light LEDs
• III-V Nitride Device Structures on Patterned Substrates
• Growth of Semipolar III-V Nitride Films with Lower Defect Density
• Enhanced Optical Polarization of Nitride LEDs by Increased Indium Incorporation
• Semipolar-Based Yellow, Green, Blue LEDs with Improved Performance
• Hexagonal Wurtzite Type Epitaxial Layer with a Low Alkali-Metal Concentration
• Photoelectrochemical Etching Of P-Type Semiconductor Heterostructures
• Photoelectrochemical Etching for Chip Shaping Of LEDs
• Highly Efficient Blue-Violet III-Nitride Semipolar Laser Diodes
• Defect Reduction in GaN films using in-situ SiNx Nanomask
• Semi-polar LED/LD Devices on Relaxed Template with Misfit Dislocation at Hetero-interface
• Limiting Strain-Relaxation in III-Nitride Heterostructures by Substrate Patterning
• Suppression of Defect Formation and Increase in Critical Thickness by Silicon Doping
• High Efficiency Semipolar AlGaN-Cladding-Free Laser Diodes
• Low-Cost Zinc Oxide for High-Power-Output, GaN-Based LEDs (UC Case 2010-183)
• Low-Cost Zinc Oxide for High-Power-Output, GaN-Based LEDs (UC Case 2010-150)
• Method for Growing Self-Assembled Quantum Dot Lattices
• Method for Increasing GaN Substrate Area in Nitride Devices
• Flexible Arrays of MicroLEDs using the Photoelectrochemical (PEC) Liftoff Technique
• Optimization of Laser Bar Orientation for Nonpolar Laser Diodes
• UV Optoelectronic Devices Based on Nonpolar and Semi-polar AlInN and AlInGaN Alloys
• Low-Droop LED Structure on GaN Semi-polar Substrates
• Improved Fabrication of Nonpolar InGaN Thin Films, Heterostructures, and Devices
• Growth of High-Performance M-plane GaN Optical Devices
• Method for Enhancing Growth of Semipolar Nitride Devices
• Transparent Mirrorless (TML) LEDs
• Solid Solution Phosphors for Use in Solid State White Lighting Applications
• Technique for the Nitride Growth of Semipolar Thin Films, Heterostructures, and Semiconductor Devices
• Planar, Nonpolar M-Plane III-Nitride Films Grown on Miscut Substrates
• High-Efficiency, Mirrorless Non-Polar and Semi-Polar Light Emitting Devices
• High Light Extraction Efficiency III-Nitride LED
• Tunable White Light Based on Polarization-Sensitive LEDs
• Method for Improved Surface of (Ga,Al,In,B)N Films on Nonpolar or Semipolar Subtrates
• Improved Anisotropic Strain Control in Semipolar Nitride Devices
• III-Nitride Tunnel Junction with Modified Interface
• Enhanced Light Extraction LED with a Tunnel Junction Contact Wafer Bonded to a Conductive Oxide
• Increased Light Extraction with Multistep Deposition of ZnO on GaN
• Hybrid Growth Method for Improved III-Nitride Tunnel Junction Devices
• Calcium Impurity Reduction for Improved Light-Emitting Devices
• Contact Architectures for Tunnel Junction Devices
• New Blue Phosphor for High Heat Applications
• Internal Heating for Ammonothermal Growth of Group-III Nitride Crystals
• Methods for Fabricating III-Nitride Tunnel Junction Devices
• Laser Diode System For Horticultural Lighting
• Fabricating Nitride Layers
• Reduction in Leakage Current and Increase in Efficiency of III-Nitride MicroLEDS
• Vertical Cavity Surface-Emitting Lasers with Continuous Wave Operation
• Laser Lighting System Incorporating an Additional Scattered Laser

Tech ID/UC Case

21914/2005-565-0

Related Cases

2005-565-0

*Abstract

Sidewall lateral epitaxial overgrowth (SLEO) of non-polar a-plane and m-plane GaN that results in several device improvements such as longer lifetimes, less leakage current, more efficient doping and higher output efficiency.

*IP Issue Date

Apr 22, 2008

*Principal Investigator

Name: Steven DenBaars

Department:

Name: Bilge Imer

Department:

Name: James Speck

Department:

Country/Region

USA