VCSEL Contact Extension Structure for Flat Semiconductor Arrays

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Solution Overview

Problem

Semiconductor devices often exhibit distortion due to intrinsic stresses from lattice parameter mismatches and thermal expansion coefficient differences, which can be problematic for applications requiring flat arrays of semiconductor devices.

Innovation Solution

The semiconductor device design includes a contact extension that counteracts intrinsic stresses near the substrate and epitaxial layer interface, allowing the array to adopt a substantially planar form above the melting temperature of the electrically conductive adhesive material, which is then fixed in this form below the melting temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If strain compensation layers are implemented to counteract intrinsic stresses, then distortion is reduced, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
ImproveflatnessVSAvoidstructure
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent extracts the strain compensation function from a separate dielectric layer and integrates it into the contact extension structure itself. The contact extension serves dual purposes: providing electrical connection and counteracting intrinsic stresses through its material composition and structural design, thereby eliminating the need for additional compensation layers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The contact extension is designed to perform multiple functions simultaneously: it provides electrical connection between components and acts as a strain compensation element. By selecting appropriate materials with specific stress properties, the same structure that connects components electrically also compensates for lattice mismatch and thermal expansion stresses, reducing overall device distortion.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If strain compensation layers are added to reduce distortion, then flatness is improved, but manufacturing process complexity increases

Engineering Contradiction:
Improvedistortion controlVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent merges the strain compensation function with the contact extension deposition process. Instead of adding separate compensation layers that require additional manufacturing steps, the contact extension is designed and deposited to inherently provide stress compensation, combining multiple functions into a single integrated structure and process step.

Inventive Principle:
Principle #5Merging (Combining)

3Shape

If contact extension with stress counteraction is used, then planarity is maintained at elevated temperatures, but material selection and process control requirements increase

Engineering Contradiction:
ImproveplanarityVSAvoidmaterial compatibility
Core Design Contradiction:
ShapeVSAdaptability or versatility

Solution Approach 1:

The patent utilizes changes in material parameters, specifically selecting contact extension materials with appropriate stress properties, thermal expansion coefficients, and lattice parameters that match or complement the substrate and epitaxial layer. By carefully controlling material composition and deposition parameters, the contact extension can counteract intrinsic stresses and maintain planarity across a range of temperatures and conditions.

Inventive Principle:
Principle #35Parameter changes

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 design effectively reduces distortion in semiconductor devices, ensuring they remain substantially planar, which is critical for maintaining device performance and reliability in applications where flatness is essential.

Implementation Method 1

the contact extension is operable to counteract the intrinsic stresses within the vicinity of the first side of the substrate and the first side of the epitaxial layer

Methodology Applied
Scientific EffectStress counteraction:

Implementation Method 2

below the melting temperature of the electrically conductive adhesive material

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

the electrically conductive adhesive material is operable to fix the array of semiconductor devices into the form

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3732707B1Semiconductor devices and methods for producing the same
Publication Date: 2025.05.28 AMS OSRAM INT GMBH
  • EP3732707B1 patent drawingFigure 1A~1E
  • EP3732707B1 patent drawingFigure 2
  • EP3732707B1 patent drawingFigure 3

AI summary

Semiconductor devices, such as vertical-cavity surface-emitting lasers, and methods for manufacturing the same, are disclosed. The semiconductor devices include contact extensions and electrically conductive adhesive material, such as fusible metal alloys or electrically conductive composites. In some instances, the semiconductor devices further include structured contacts. These components enable the production of semiconductor devices having minimal distortion. For example, arrays of vertical-cavity surface-emitting lasers can be produced exhibiting little to no bowing. Semiconductor devices having minimal distortion exhibit enhanced performance in some instances.