LED Manufacturing Using Carbon Nanotube Release Layer

Solution Overview

Problem

Conventional methods for making light emitting diodes (LEDs) involve complex and costly processes for roughening the light extraction surface, which can damage the semiconductor lattice structure and increase manufacturing costs.

Innovation Solution

A method involving a carbon nanotube layer on a substrate to create a patterned epitaxial growth surface for growing semiconductor layers, reducing lattice dislocation and simplifying the manufacturing process by using the carbon nanotube layer as a mask and subsequently removing it to expose the semiconductor surface for further layer growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the light extraction surface is etched to roughen the top surface, then light extraction efficiency is improved, but the manufacturing process becomes complex and costly, and the lattice structure of the semiconductor layer may be destroyed

Engineering Contradiction:

Improvelight extraction efficiencyVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by growing a patterned buffer layer with predefined patterns (such as holes, grooves, or pillars) before depositing the active and electrode layers. This pre-formed patterned structure serves as the light extraction surface, eliminating the need for subsequent etching processes to roughen the surface. The patterns are created during the epitaxial growth stage using techniques like selective area growth or lithography followed by release layer removal, thereby simplifying the overall manufacturing process while maintaining improved light extraction efficiency.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the light extraction surface is etched to roughen the top surface, then light extraction efficiency is improved, but manufacturing cost increases

Engineering Contradiction:

Improvelight extraction efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by growing a patterned buffer layer with predefined patterns (such as holes, grooves, or pillars) before depositing the active and electrode layers. This pre-formed patterned structure serves as the light extraction surface, eliminating the need for subsequent etching processes to roughen the surface. The patterns are created during the epitaxial growth stage using techniques like selective area growth or lithography followed by release layer removal, thereby simplifying the overall manufacturing process while maintaining improved light extraction efficiency.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the light extraction surface is etched to roughen the top surface, then light extraction efficiency is improved, but the lattice structure of the semiconductor layer may be destroyed

Engineering Contradiction:

Improvelight extraction efficiencyVSAvoidlattice structure integrity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by growing a patterned buffer layer with predefined patterns (such as holes, grooves, or pillars) before depositing the active and electrode layers. This pre-formed patterned structure serves as the light extraction surface, eliminating the need for subsequent etching processes to roughen the surface. The patterns are created during the epitaxial growth stage using techniques like selective area growth or lithography followed by release layer removal, thereby simplifying the overall manufacturing process while maintaining improved light extraction efficiency.

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 approach reduces dislocation defects and manufacturing costs while enhancing light extraction efficiency by using a carbon nanotube layer to pattern the growth surface, resulting in a more efficient and cost-effective LED production process.

Implementation Method 1

epitaxially growing a first semiconductor layer on the first epitaxial growth surface

Methodology Applied

Scientific EffectEpitaxy: Epitaxy

Implementation Method 2

exposing a surface of the first semiconductor layer by removing the substrate and the carbon nanotube layer

Methodology Applied

Scientific EffectEtching:

Data Source

PatentUS8759130B2Method for making light emitting diode

Publication Date: 2014.06.24 HON HAI PRECISION INDUSTRY CO LTD

AI summary

A method for making a light emitting diode includes the following steps. A substrate having a first epitaxial growth surface is provided. A carbon nanotube layer is placed on the first epitaxial growth surface of the substrate. A surface of the first semiconductor layer is exposed by removing the substrate and the carbon nanotube layer. The surface of the first semiconductor layer is defined as a second epitaxial growth surface. An active layer and a second semiconductor layer are grown on the second epitaxial growth surface in that order. A surface of the active layer contacted the first semiconductor layer engages with the second epitaxial growth surface. A part of the first semiconductor layer is exposed by etching a part of the active layer and the second semiconductor layer. A first electrode is applied on the first semiconductor layer and a second electrode is applied on the second semiconductor layer.