Silicon-Based Molten Composition for SiC Crystal Growth

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Solution Overview

Problem

Current methods for growing silicon carbide single crystals, such as the sublimation and chemical vapor deposition methods, face limitations in production cost and crystal quality due to defects like micropipes and limited thickness, and there is a need for a method that can achieve rapid crystal growth with reduced process time and cost.

Innovation Solution

A silicon-based fusion composition comprising silicon, scandium, and aluminum, with specific atomic percentage ratios, is used in a solution growth method to enhance carbon solubility and crystallinity, allowing for high-speed growth of silicon carbide single crystals with improved quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sublimation method is used to grow silicon carbide single crystal at high temperature, then the crystal can be grown, but defects such as micropipes and lamination defects are likely to occur

Engineering Contradiction:
Improvecrystal qualityVSAvoiddefects (micropipes and lamination defects)
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the growth parameters by using a solution growth method at lower temperatures (1800-2000°C) compared to sublimation methods, and by controlling the composition of the silicon-based molten composition with specific metal additives to reduce defect formation while maintaining crystal quality

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite silicon-based molten composition containing silicon and specific metals (such as aluminum, titanium, zirconium, chromium, or scandium) to grow the silicon carbide crystal, where the metal additives modify the molten composition properties to reduce defect formation during crystal growth

Inventive Principle:
Principle #40Composite materials

2Length of moving object

If the chemical vapor deposition method is used, then the crystal can be grown, but the thickness is limited to thin film level

Engineering Contradiction:
Improvecrystal thicknessVSAvoidgrowth speed
Core Design Contradiction:
Length of moving objectVSProductivity

Solution Approach 1:

The invention changes the growth method from chemical vapor deposition to solution growth, enabling thicker crystal growth by utilizing a molten composition medium that allows for higher growth speeds and greater thickness achievement

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the sublimation method is used to grow silicon carbide single crystal, then the crystal can be grown, but the production cost increases

Engineering Contradiction:
Improvecrystal qualityVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the growth temperature parameter to a lower range (1800-2000°C) compared to sublimation methods, and uses a solution growth mechanism that reduces production costs while maintaining crystal quality through controlled molten composition

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

The composition enables rapid crystal growth with reduced process time and cost, producing high-quality silicon carbide single crystals by optimizing carbon solubility and crystallinity, thereby overcoming the limitations of existing methods.

Implementation Method 1

The silicon-based fusion composition may have a carbon solubility of 5% or more. The scandium may increase the carbon solubility in the silicon-based fusion.

Methodology Applied
Scientific EffectCarbon solubility: Absorption (physical)

Implementation Method 2

a silicon-based fusion composition which is used for a solution growth method for forming a silicon carbide single crystal

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

solution growth method for forming a silicon carbide single crystal

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Data Source

PatentEP3575451B1Silicon-based molten composition and method for manufacturing silicon carbide single crystal using same
Publication Date: 2024.08.28 LG CHEM LTD
  • EP3575451B1 patent drawingFigure 1
  • EP3575451B1 patent drawingFigure 2A
  • EP3575451B1 patent drawingFigure 2B

AI summary

The present disclosure relates to a silicon-based fusion composition used for a solution growth method for forming a silicon carbide single crystal, and represented by the following Formula 1, including silicon, a first metal (M1), scandium (Sc) and aluminum (Al):         SiaM1bSccAld     (Formula 1) wherein a is more than 0.4 and less than 0.8, b is more than 0.2 and less than 0.6, c is more than 0.01 and less than 0.1, and d is more than 0.01 and less than 0.1.