Group III Nitride Buffer Layer for Dislocation Reduction

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Solution Overview

Problem

Existing methods for manufacturing semiconductor structures based on element III nitrides, such as gallium nitride on substrates, face challenges due to high through-dislocation densities, which increase leakage currents and deteriorate luminescence efficiency in light-emitting devices. Additionally, these methods require empirical optimization of nanoporous silicon nitride layers, making them costly and non-generic.

Innovation Solution

A method involving the deposition of a crystalline layer that covers the entire surface of the buffer layer to prevent oxidation and eliminate the need for empirical optimization of nanoporous layers, allowing for the growth of gallium nitride with reduced dislocation density and enabling the storage of substrates before deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a nanoporous silicon nitride layer is deposited to reduce dislocation density, then through-dislocation density is reduced, but the process requires empirical optimization making it costly and non-generic

Engineering Contradiction:
Improvethrough-dislocation densityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the deposition parameters of the silicon nitride layer to achieve a specific porosity range (20-80%) that optimizes dislocation reduction while enabling generic manufacturing. By controlling the porosity parameter within this range, the process becomes more standardized and less dependent on empirical optimization for each specific case.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The silicon nitride layer acts as an intermediary buffer layer between the substrate and the gallium nitride layer. This intermediate layer with controlled porosity serves as a template that reduces dislocation propagation while providing a standardized interface that simplifies the manufacturing process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If conventional epitaxy is used on substrate, then manufacturing is simple, but high through-dislocation density increases leakage currents and deteriorates luminescence efficiency

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidluminescence efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

A buffer layer comprising a first layer based on element III nitride and a second crystalline layer is introduced as an intermediary structure between the substrate and the active semiconductor layer. This buffer layer structure filters out dislocations while maintaining manufacturing feasibility, thereby improving luminescence efficiency without excessive complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer layer uses a composite structure combining element III nitride material with a crystalline layer having specific orientation relationships. This composite approach leverages the beneficial properties of both materials to reduce dislocation density while maintaining compatibility with conventional manufacturing processes.

Inventive Principle:
Principle #40Composite materials

3Reliability

If crystalline layer is deposited to cover entire buffer layer surface, then oxidation is prevented and storage is enabled, but deposition time increases

Engineering Contradiction:
Improvesurface protectionVSAvoiddeposition time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The crystalline layer is deposited with specific local crystallographic orientation (e.g., <100> orientation) that provides optimal protection against oxidation. By controlling the local quality and orientation of the crystalline layer, effective protection is achieved with minimal deposition time rather than requiring complete coverage regardless of orientation.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces through-dislocation density in gallium nitride layers, enhances luminescence efficiency, and allows for cost-effective, generic manufacturing processes by eliminating the need for empirical optimization of nanoporous layer parameters.

Implementation Method 1

a method involving the deposition of a crystalline layer that covers the entire surface of the buffer layer

Methodology Applied
Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

a diffraction image of said crystalline layer obtained by diffraction of electrons at grazing incidence

Methodology Applied
Scientific EffectElectron diffraction: Diffraction

Data Source

PatentEP3248213B1Production of a semiconductor support based on group iii nitrides
Publication Date: 2023.09.06 CENT NAT DE LA RECH SCI (C N R S)
  • EP3248213B1 patent drawingFigure 1~2
  • EP3248213B1 patent drawingFigure 3~4
  • EP3248213B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for producing a support for the production of a semiconductor structure based on group III nitrides, characterised in that the method comprises the steps of: formation (100) of a buffer layer (20) on a substrate (10), said buffer layer comprising an upper surface layer based on group III nitrides; and deposition (200) of a crystalline layer (30) on the buffer layer, said crystalline layer being deposited from silicon atoms so as to cover the entire surface of the upper layer based on group III nitrides. The invention also relates to a support produced by the method, to a semiconductor structure based on the support, and to the method for the production thereof.