Offcut Gallium Oxide Crystal Growth for Large Single-Crystal Sheets

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The industry faces challenges in producing large-sized, high-quality gallium oxide single crystals with specific offcuts and controlled polycrystallinity and twinning, particularly using the Edge-Defined Film-Fed Growth (EFG) method, due to cost and size limitations, which hinders widespread implementation in high power applications.

Innovation Solution

An EFG growth apparatus and method are developed to grow gallium oxide single crystals with a principal face oriented offcut from the (001) crystallographic orientation, utilizing a high aspect ratio crucible, dynamic thermal gradient control, and precise growth environment management to achieve crystals with a full width half mass (FWHM) of less than 60 arcsec and offcuts between 2 and 20 degrees, enabling large-sized sheets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If gallium oxide crystals are grown using conventional pull direction methods followed by cutting and grinding, then crystal orientation can be obtained, but production cost increases and manufacturing complexity increases

Engineering Contradiction:

Improvecrystal orientationVSAvoidproduction cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Instead of growing crystals in a conventional pull direction and then cutting/grinding to achieve orientation, the invention inverts the approach by growing the crystal with the desired orientation directly during the growth process using EFG method with specific offcut angles, eliminating subsequent cutting and grinding steps

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The desired crystal orientation and offcut are established during the growth process itself rather than as a post-processing step. The EFG apparatus is configured with specific geometric parameters and growth conditions that preliminarily establish the correct orientation before the crystal is even completed

Inventive Principle:

Principle #10Preliminary action

2Area of stationary object

If gallium oxide sheets are scaled up in size, then larger area is achieved, but polycrystallinity and twinning increase

Engineering Contradiction:

Improvesheet sizeVSAvoidpolycrystallinity and twinning

Core Design Contradiction:

Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The invention changes key growth parameters including temperature gradient, growth rate, and crucible geometry to enable large-area crystal growth while maintaining single-crystal quality. Specific parameters like offcut angle (2-20 degrees) and growth temperature profiles are optimized to prevent polycrystallinity and twinning even in large sheets

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The use of offcut orientations (2-20 degrees from principal face) introduces asymmetry in the crystal growth process that helps maintain single-crystal structure over large areas. The asymmetric growth conditions prevent the formation of twin boundaries and promote uniform single-crystal development

Inventive Principle:

Principle #4Asymmetry

3Productivity

If EFG method is used to grow large-sized gallium oxide sheets, then productivity increases, but manufacturing precision and quality control become more difficult

Engineering Contradiction:

Improveproduction rateVSAvoidquality control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The invention implements feedback control through real-time monitoring of growth parameters such as temperature, growth rate, and crystal morphology. This allows continuous adjustment of growth conditions to maintain high quality standards even during large-scale production, ensuring consistent FWHM and offcut angles across all produced sheets

Inventive Principle:

Principle #23Feedback

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 solution enables the production of gallium oxide sheets with improved size, quality, and uniformity, overcoming scaling issues and reducing defects, facilitating their use in high power applications such as substrates, LEDs, and temperature sensors.

Implementation Method 1

bringing a seed crystal having a (001) crystallographic orientation in contact with a base melt

Methodology Applied

Scientific EffectDissolution and reprecipitation:

Data Source

PatentUS20260035833A1Apparatus and method for growth of gallium oxide crystal with an offcut

Publication Date: 2026.02.05 LUXIUM SOLUTIONS LLC

AI summary

Apparatuses and methods as described herein can be used to grow a Ga2O3 based single crystal using an Edge-defined film fed growth (EFG) method. The single gallium oxide crystal sheet can have a principle plane that is rotated from a (001) plane crystallographic orientation. In one embodiment, the rotation is between 2 and 20 degrees. The single crystal can have a full width half mass of less than 50 arcsec.