Graphene Layer Substrate Separation for Compound Semiconductor Devices

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Solution Overview

Problem

Current methods for separating substrates from compound semiconductor devices, such as laser lift-off and chemical lift-off, do not achieve high enough efficiency and often damage the nitride semiconductor, leading to defects and reduced light emitting diode performance.

Innovation Solution

A method involving the formation of a graphene-derived material layer, such as a graphene oxide layer, on a substrate, which is then transformed to separate the compound semiconductor layers, allowing for selective growth and minimization of lattice stress and defects, using techniques like chemical, heat, or photo treatments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laser lift-off or chemical lift-off methods are used to separate substrate from compound semiconductor, then substrate separation is achieved, but the nitride semiconductor is damaged and defects are generated

Engineering Contradiction:
Improvesubstrate separation efficiencyVSAvoiddamage to nitride semiconductor
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A graphene layer is introduced as an intermediary between the substrate and the compound semiconductor layer. This graphene layer serves as a buffer that absorbs thermal stress and prevents direct contact between the substrate and semiconductor, enabling clean separation without damaging the nitride semiconductor during the lift-off process

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The graphene layer is deposited on the substrate before growing the compound semiconductor layer, providing preemptive protection against thermal stress and lattice mismatch. This pre-established cushioning layer prevents defect formation before the semiconductor is exposed to harsh processing conditions

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Productivity

If conventional separation methods are used, then substrate removal is possible, but light emitting efficiency is reduced due to defects

Engineering Contradiction:
Improvesubstrate removal capabilityVSAvoidlight emitting efficiency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The graphene layer acts as a protective intermediary that enables substrate removal while preserving the quality of the nitride semiconductor layer, thereby maintaining high light emitting efficiency without the defects that would otherwise be generated by conventional separation methods

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If no graphene layer is used, then the manufacturing process is simpler, but lattice stress and crystalline defects increase

Engineering Contradiction:
Improveprocess complexityVSAvoidcrystalline quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The introduction of the graphene layer changes the thermal and mechanical parameters at the substrate-semiconductor interface, reducing thermal stress and improving heat dissipation. This parameter modification enables better crystalline quality and reduces defects during the growth and separation processes

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 approach enables the synthesis of high-quality compound semiconductor layers with reduced crystalline defects and improved light emitting efficiency by controlling lattice stress and minimizing adverse effects on the semiconductor, facilitating efficient separation of the substrate.

Implementation Method 1

The graphene layer may be transformed into a graphene oxide layer by one method among a chemical treatment method, a heat treatment method and a photo treatment method

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

The graphene oxide layer may be transformed into a transformed graphene oxide layer having a greater thickness than the graphene oxide layer by the heat treatment method

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 3

the graphene oxide layer may be reduced by the chemical treatment method and the photo treatment method into a graphene-like layer having a decreased thickness

Methodology Applied
Scientific EffectReduction: Reduction

Data Source

PatentEP2634825B1Method for manufacturing a compound semiconductor device
Publication Date: 2018.12.26 SK SILTRON CO LTD
  • EP2634825B1 patent drawingFigure 1~4
  • EP2634825B1 patent drawingFigure 5~7
  • EP2634825B1 patent drawingFigure 8~9

AI summary

According to the present invention, a method for manufacturing a compound semiconductor comprises: forming a graphene-derived material layer on either a first selected substrate or a first selected compound semiconductor layer; forming a second compound semiconductor layer of at least one layer on at least said graphene-derived material layer, and changing the graphene-derived material layer so as to separate said second compound semiconductor layer of at least one layer.