Conformal Conductive Layer Deposition for Rod-Shaped Diode Biasing

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Solution Overview

Problem

Existing manufacturing processes for optoelectronic devices with wire diodes face challenges in achieving simple and efficient electrical biasing on the front face of the substrate, often requiring conductive materials suitable for epitaxial growth or localized doping steps.

Innovation Solution

A method involving directional deposition of a lower conductive thin film on the substrate, utilizing rotational and angular oscillation movements to ensure conformal and continuous coverage of wire diodes, allowing for improved charge carrier injection and electrical biasing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional deposition methods (spin coating, dip coating, spray coating, inkjet printing) are used to form conductive layers, then the process is simple and fast, but the layers are non-uniform, discontinuous, or have poor coverage on high-aspect-ratio structures

Engineering Contradiction:
Improvedeposition speedVSAvoidlayer uniformity and continuity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces conventional mechanical deposition methods (spin coating, dip coating, spray coating, inkjet printing) with a field-based directional deposition process. Conductive particles are transported through a liquid medium and directed onto the substrate using electric or magnetic fields, enabling precise control over particle placement while maintaining high deposition speed and achieving uniform, continuous layers on complex structures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If conventional coating methods are used, then the process is easy to implement, but the conductive layers cannot achieve conformal coverage on high-aspect-ratio structures

Engineering Contradiction:
Improveprocess simplicityVSAvoidconformal coverage
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the fundamental parameters of the deposition process by using field-based control (electric or magnetic fields) instead of mechanical contact methods. This allows particles to be directed along field lines that conform to the substrate geometry, achieving uniform coverage on high-aspect-ratio structures while keeping the process relatively simple through automated field application.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If thick conductive layers are deposited to ensure continuity, then coverage is improved, but the deposition time increases and productivity decreases

Engineering Contradiction:
Improvelayer continuityVSAvoiddeposition time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies local quality by using field-based directional deposition to place conductive particles precisely where needed on the substrate surface. The field distribution can be locally adjusted to ensure continuous coverage in critical areas while maintaining optimal deposition rates elsewhere, achieving layer continuity without requiring uniformly thick deposits across the entire substrate, thus reducing overall deposition time.

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

Enables effective electrical biasing of wire diodes by ensuring continuous and uniform deposition of the conductive thin film, facilitating parallel connection and improved charge carrier injection, thereby enhancing the performance of optoelectronic devices.

Implementation Method 1

a step of producing a thin conductive layer conformally and continuously by directional deposition through a liquid medium of conductive particles onto a substrate in a deposition chamber

Methodology Applied
Scientific EffectElectrophoresis: Electrophoresis

Implementation Method 2

wherein the step of producing the thin conductive layer comprises directing the conductive particles onto the substrate using an external electric or magnetic field

Methodology Applied
Scientific EffectMagnetic field effect: Magnetic Field

Data Source

PatentEP4377491B1Process for fabricating an optoelectronic device comprising a step of producing a thin conductive layer conformally and continously by directional deposition
Publication Date: 2026.04.29 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4377491B1 patent drawingFigure 1A~1B
  • EP4377491B1 patent drawingFigure 2A~2C
  • EP4377491B1 patent drawingFigure 3A~3B

AI summary

The invention relates to a process for fabricating an optoelectronic device (1) comprising a substrate (20) and rod-shaped diodes (10) having a spacing ratio h/d at least equal to (1), the process comprising a step of producing a thin conductive layer (23) by directional physical vapour deposition, the substrate (20) having a rotary periodic motion and an oscillatory periodic motion so that the thin conductive layer (23) is deposited conformally and continuously on the substrate (20) and the sidewalls of the rod-shaped diodes (10).