Sapphire Single Crystal Growth with Concentric Hexagonal Ring Control

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Solution Overview

Problem

Existing methods for producing sapphire single crystals do not effectively control geometric patterns and lattice defects, leading to inconsistent deformation and reduced quality in subsequent semiconductor applications.

Innovation Solution

A method and device utilizing a crucible with controlled temperature layers and selective heating/cooling to create geometric patterns, particularly concentric hexagonal rings, during the growth process of sapphire single crystals, ensuring consistent deformation and improved quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional crystal growth methods are used, then sapphire single crystals can be produced, but geometric patterns and lattice defects cannot be effectively controlled, leading to inconsistent deformation

Engineering Contradiction:
Improvecontrol of geometric patterns and lattice defectsVSAvoiddeformation consistency
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies local quality by creating specific temperature zones within the crucible. Different regions of the melt are maintained at different temperatures, with cooler zones promoting desired geometric patterns and lattice structures while hotter zones ensure complete melting. This spatial variation in temperature quality enables precise control over crystal growth characteristics and defect formation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by dynamically adjusting temperature parameters during the crystal growth process. By varying temperature profiles, cooling rates, and thermal gradients, the method controls the formation of geometric patterns and minimizes lattice defects. These parameter changes are critical for achieving consistent deformation characteristics in the final sapphire crystal.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the starting material is heated above melting point to liquefy it, then crystal growth from melt is enabled, but uncontrolled thermal conditions lead to inconsistent crystal structure

Engineering Contradiction:
Improvecrystal growth from meltVSAvoidcrystal structure consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The heating system is segmented into multiple independent zones within the crucible, each capable of independent temperature control. This segmentation allows different regions to serve different functions: some zones maintain high temperatures for melting, while others provide controlled cooling for crystal growth. The segmented approach enables precise thermal management throughout the crystal growth process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic temperature control where heating and cooling conditions are continuously adjusted during crystal growth. The system transitions from initial high-temperature melting to controlled cooling phases, with real-time modifications to thermal parameters. This dynamic approach ensures optimal conditions at each stage of crystal formation, maintaining structural consistency.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If temperature is dropped slowly below melting point for melt crystallization, then single crystal formation is promoted, but production time increases

Engineering Contradiction:
Improvesingle crystal qualityVSAvoidproduction time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies preliminary action by pre-positioning a seed crystal at the bottom of the crucible before melting the starting material. This seed crystal provides a ready-made lattice structure that guides the crystallization process. When the melt cools, atoms preferentially deposit on the seed crystal's lattice, promoting single crystal growth from the outset rather than requiring slow cooling to spontaneously form ordered structures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The seed crystal serves as an intermediary between the melt and the growing single crystal. It mediates the crystallization process by providing a template for atomic arrangement. The seed crystal's lattice structure guides the orientation and growth of subsequent crystal layers, enabling faster single crystal formation compared to spontaneous crystallization from the melt.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method and device produce sapphire single crystals with defined geometric patterns, enhancing deformation consistency and quality, improving the reliability and efficiency of semiconductor manufacturing processes.

Implementation Method 1

the starting material must be heated above its melting point in a crucible of a suitable furnace and thus liquefied

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

For the melt to crystallize on the seed crystal, the temperature must drop slowly enough below the melting point

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Data Source

PatentEP4685275A1Method and device for producing sapphire single crystal and sapphire single crystal
Publication Date: 2026.01.28 FAMETEC GMBH
  • EP4685275A1 patent drawingFigure 1~2
  • EP4685275A1 patent drawingFigure 3
  • EP4685275A1 patent drawing

AI summary

The invention relates to a sapphire single crystal (4) and a method and apparatus (1) for producing it, wherein the sapphire single crystal (4) comprises a plurality of layers (11) arranged in a C-axis (7), wherein each layer (11) has a cross-sectional topography (12), wherein the cross-sectional topographies (12) of the layers (11) repeat with respect to geometric patterns (13) formed in the cross-sectional topographies (12), wherein the geometric patterns (13) are predominantly composed of polygonal rings, in particular of concentric hexagonal or concentric hexagonal rings.