Nanostructured LED Substrate Fabrication via Thermal Mask Etching

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Solution Overview

Problem

Conventional Light Emitting Diodes (LEDs) suffer from degraded light extraction efficiency due to total internal reflection, with existing methods like surface texturing and patterned substrates being costly and difficult to manufacture at nanometer accuracy, and requiring precise controllability.

Innovation Solution

A method involving the formation of nano agglomerations on a substrate through a simple thermal treatment process, using these agglomerations as a mask for etching to create nano structures, which enhances light extraction efficiency by reducing crystal defects and improving light refraction and reflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If surface texturing or patterned substrate techniques are used to improve light extraction efficiency, then light extraction efficiency is improved, but manufacturing cost and process complexity increase significantly

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidmanufacturing cost and process complexity
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The invention changes the manufacturing approach from complex nanometer-scale lithography to a simple thermal treatment process. By heating the substrate to form nano agglomerations through phase separation or precipitation, the patent achieves nanostructure formation without requiring expensive lithography equipment or complex multi-step fabrication processes, thereby reducing manufacturing cost and complexity while maintaining improved light extraction efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces mechanical/lithographic fabrication methods with a thermal field-based approach. Instead of using photolithography masks, etching, and deposition processes to create nanostructures, the patent uses thermal treatment to induce spontaneous formation of nano agglomerations on the substrate surface, substituting complex mechanical fabrication with a simpler thermal process

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

2Manufacturing precision

If nanometer-scale lithography techniques are used to create precise patterns on substrates, then manufacturing precision is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvenanometer pattern accuracyVSAvoidfabrication process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention employs self-organization of materials during thermal treatment. The nano agglomerations form spontaneously through phase separation or precipitation processes driven by thermal energy, without requiring external patterning tools or masks. This self-organizing behavior naturally produces nanostructures with appropriate dimensions and distribution, achieving manufacturing precision without complex fabrication processes

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention uses a simple, inexpensive thermal treatment process instead of expensive, complex lithography equipment. The thermal process can be applied to entire batches of substrates simultaneously and requires minimal equipment, making it a cost-effective alternative to nanometer-scale lithography while achieving the desired nanostructure formation

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 allows for the fabrication of high-quality light emitting devices with improved light extraction efficiency and reliability at lower costs, using a more straightforward and cost-effective process compared to traditional nanometer-scale lithography techniques.

Implementation Method 1

forming a plurality of nano agglomerations on the substrate through a simple thermal treatment process

Methodology Applied
Scientific EffectPhase separation: Phase Change

Implementation Method 2

forming a plurality of nano agglomerations on the substrate through a simple thermal treatment process

Methodology Applied
Scientific EffectThermal treatment: Heat Treatment

Implementation Method 3

using these agglomerations as a mask for etching to create nano structures

Methodology Applied
Scientific EffectPhotomasking:

Implementation Method 4

etching to create nano structures

Methodology Applied
Scientific EffectEtching:

Implementation Method 5

some of the light generated from inside of the LED is trapped within the LED by reflection from an interface between the two materials such as the LED and air beyond a critical angle

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 6

improving light refraction and reflection

Methodology Applied
Scientific EffectLight refraction: Refraction

Data Source

PatentEP1798780B1Method of fabricating a light emitting device
Publication Date: 2020.10.07 LG INNOTEK CO LTD
  • EP1798780B1 patent drawingFigure 1~2
  • EP1798780B1 patent drawingFigure 3~4b
  • EP1798780B1 patent drawingFigure 4c~4e

AI summary

A method of fabricating a substrate (100,200,300) with nano structures (105,205,305), light emitting device using the substrate (100,200,300) and a manufacturing method thereof, wherein a substrate (100,200,300) for growing a light emitting device is formed with nano agglomerations (125), and the substrate (100,200,300) is etched by using the agglomerations (125) as a mask to allow nano structures (105,205,305) to be formed on the substrate (100,200,300), thereby enabling to grow a crystal defect-reduced, reliability-improved, good quality light emitting structure, and wherein the light emitting structure is formed with nano structures (105,205,305) to enhance the light extraction efficiency.