Mg2Si Single Crystal Orientation Control for Infrared Sensitivity

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Solution Overview

Problem

The presence of low-angle grain boundaries in Mg2Si single crystals reduces semiconductor characteristics, limiting their effectiveness in infrared light detection.

Innovation Solution

Control the variation in crystal orientation of Mg2Si single crystals to a range of ±0.020° using a pBN crucible coated with BN, and employ dopants like B, Li, Al, Ag, P, As, and Sb to enhance carrier concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Mg2Si single crystal is used for infrared light detection, then light detection sensitivity in infrared region is improved, but low-angle grain boundaries are generated which reduce semiconductor characteristics

Engineering Contradiction:

Improvelight detection sensitivityVSAvoidcrystal orientation uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the parameter of crystal orientation variation from conventional ranges to a specific range of ±0.020° or less. This parameter change ensures uniform crystal growth and prevents low-angle grain boundary formation, thereby maintaining high semiconductor characteristics while achieving reliable infrared light detection sensitivity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention employs a vertical gradient freeze method which uses controlled temperature gradients (thermal fields) to guide uniform crystal growth. By establishing a controlled thermal environment during crystal growth, the method achieves uniform crystal orientation and prevents grain boundary formation, resolving the contradiction between detection sensitivity and crystal quality.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Ease of manufacture

If conventional crystal growth methods are used, then production process is simple, but low-angle grain boundaries are generated reducing semiconductor characteristics

Engineering Contradiction:

Improvecrystal growth process simplicityVSAvoidsemiconductor characteristics

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention specifies precise parameter ranges for crystal orientation (±0.020° or less) and controlled temperature gradients during growth. These parameter specifications maintain relatively simple production processes while ensuring high semiconductor characteristics by preventing low-angle grain boundaries through uniform crystal growth.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The vertical gradient freeze method employs continuous controlled cooling to grow the crystal uniformly from bottom to top. This continuous controlled process maintains simplicity while ensuring uniform crystal orientation throughout the entire crystal structure, preventing grain boundary formation and maintaining high semiconductor characteristics.

Inventive Principle:

Principle #20Continuity of useful action

3Device complexity

If crystal orientation variation is not controlled, then manufacturing process is easier, but low-angle grain boundaries reduce electrical characteristics

Engineering Contradiction:

Improvecrystal growth control complexityVSAvoidelectrical characteristics

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The invention establishes specific parameter targets for crystal orientation control (±0.020° or less) which provide clear manufacturing guidelines. These parameter specifications enable effective electrical characteristics without excessive process complexity, as the controlled orientation prevents low-angle grain boundaries that would otherwise degrade device performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention implements measurement and control of crystal orientation during the growth process to ensure it remains within ±0.020°. This feedback mechanism monitors and adjusts growth conditions in real-time, maintaining electrical characteristics without requiring overly complex manufacturing systems.

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

Suppresses the generation of low-angle grain boundaries, improving electrical characteristics and increasing light detection sensitivity in the infrared region, enabling advanced infrared light receiving elements.

Implementation Method 1

a photodetection element with a semiconductor material... elements that convert light signals into electrical signals

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

a variation in crystal orientation as measured by XRD

Methodology Applied

Scientific EffectX-ray diffraction: X-Ray

Data Source

PatentUS12448704B2Mg2Si single crystal, Mg2Si single crystal substrate, infrared light receiving element and method for producing Mg2Si single crystal

Publication Date: 2025.10.21 JX ADVANCED METALS CORP

AI summary

Provided is a Mg2Si single crystal in which generation of low-angle grain boundaries in the crystal is satisfactorily suppressed. A Mg2Si single crystal, wherein a variation in crystal orientation as measured by XRD is in a range of ±0.020°.