3D Diode Optoelectronic Device via Epitaxial Segmentation

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Solution Overview

Problem

Existing optoelectronic devices with a matrix of light-emitting diodes face issues due to the etching process required to individualize diodes, which can lead to structural defects and reduced light intensity per pixel, affecting their optical and electronic properties.

Innovation Solution

The optoelectronic device features conductive nucleation strips and upper conductive strips forming bias electrodes, allowing for independent activation of diodes without the need for etching, thereby preserving the diodes' properties and enhancing light intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If etching is used to individualize diodes, then diodes can be separated and controlled individually, but structural defects are formed and light intensity is reduced

Engineering Contradiction:
ImproveIndividual control of diodesVSAvoidStructural integrity of diodes
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies segmentation by dividing the continuous semiconductor layer into discrete diode structures through localized growth on separated nucleation strips. The dielectric layer segments the structure by electrically isolating adjacent diodes, eliminating the need for etching while achieving individual control. This resolves the contradiction by providing diode individualization through additive segmentation rather than subtractive etching.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent inverts the conventional approach by using localized epitaxial growth on pre-patterned nucleation strips instead of etching completed diodes. Rather than starting with a continuous layer and removing material to create individual diodes, the method starts with isolated nucleation sites and grows diodes only where needed. This inversion eliminates structural defects while maintaining individual diode control.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If etching is used to individualize diodes, then diodes can be separated, but the emissive surface area is reduced

Engineering Contradiction:
ImproveDiode individualizationVSAvoidEmissive surface area
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The dielectric layer segments the semiconductor structure into isolated diodes while allowing each diode to maintain its full emissive surface area. By using localized growth on separated nucleation strips rather than etching, the method preserves the complete top surface of each diode for light emission, eliminating the area loss that occurs with etching-based individualization.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If etching is used to individualize diodes, then diodes can be controlled individually, but manufacturing complexity increases

Engineering Contradiction:
ImproveIndividual diode controlVSAvoidManufacturing process complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent inverts the manufacturing sequence by performing localized growth before any potential etching steps. Nucleation strips are formed first, then diodes grow locally on these strips through epitaxy. This inversion eliminates the need for subsequent etching steps to individualize diodes, simplifying the manufacturing process while maintaining individual control capability.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The nucleation strips are prepared in advance as pre-patterned growth sites before diode formation. This preliminary action establishes the spatial distribution and electrical isolation of future diodes, eliminating the need for complex etching processes later. The preliminary patterning of nucleation strips simplifies the overall manufacturing complexity while enabling individual diode control.

Inventive Principle:
Principle #10Preliminary action

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 solution improves the homogeneity and intensity of light emission by eliminating the etching step, resulting in higher resolution and light intensity without compromising the diodes' optical and electronic properties.

Implementation Method 1

conductive nucleation strips forming first bias electrodes, distinct from each other and resting on said front face, made of an electrically conductive material suitable for the growth of first doped portions of diodes

Methodology Applied
Scientific EffectEpitaxy: Epitaxy

Data Source

PatentEP3479409B1Optoelectronic device comprising three-dimensional diodes
Publication Date: 2021.08.04 ALEDIA INC
  • EP3479409B1 patent drawingFigure 1
  • EP3479409B1 patent drawingFigure 2A~2C
  • EP3479409B1 patent drawingFigure 3A~3D

AI summary

The invention relates to an optoelectronic device (1) comprising: - a support that has a rear surface (3a) and a front surface (3b) opposite each other; - a plurality of nucleating conductor strips (6i) that form first polarizing electrodes; - an intermediate insulating layer (7) that covers the nucleating conductor strips (6i); - a plurality of diodes (2), each of which has a first, three-dimensional doped region (9) and a second doped region (11); - a plurality of top conductor strips (14j) that form second polarizing electrodes and rest on the intermediate insulating layer (7), each top conductor strip (14j) being disposed in such a way as to be in contact with the second doped regions (11) of a set of diodes (2) of which the first doped regions (9) are in contact with different nucleating conductor strips (6i).