SiC Substrate Contrast Imaging for Heat Treatment Evaluation

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Solution Overview

Problem

Evaluating the heat treatment environment of silicon carbide (SiC) substrates is challenging due to the difficulty in directly assessing high-temperature conditions, which affects the reproducibility of desired step-terrace structures and is influenced by inherent crystal defects and subsurface damage.

Innovation Solution

A method involving image acquisition using an electron beam incident at an inclined angle to the {0001} plane of the SiC substrate, allowing for evaluation of the heat treatment environment based on contrast information, thereby distinguishing between Si-rich and C-rich environments and equilibrium vapor pressure conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the step-terrace structure is used to evaluate heat treatment environment, then the evaluation can be performed indirectly, but the evaluation accuracy is reduced due to influence from crystal defects and subsurface damage

Engineering Contradiction:

Improveease of evaluationVSAvoidevaluation accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The invention extracts and evaluates specific contrast information from the step-terrace structure that is directly related to heat treatment environment, separating it from the influence of crystal defects and subsurface damage. By focusing on particular structural features and their contrast characteristics, the method isolates the relevant evaluation data from interfering factors.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention applies local quality by evaluating specific regions and features of the step-terrace structure rather than the entire surface. By focusing on localized contrast information that is most sensitive to heat treatment conditions, the method achieves higher evaluation accuracy while minimizing the impact of widespread defects.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If high temperature heat treatment is applied to SiC substrate, then the desired step-terrace structure can be formed, but direct evaluation of the heat treatment environment becomes difficult

Engineering Contradiction:

Improvestep-terrace structure qualityVSAvoidheat treatment environment evaluation difficulty

Core Design Contradiction:

Manufacturing precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The invention performs preliminary action by forming the step-terrace structure during heat treatment, which then serves as a permanent record or marker of the heat treatment environment. This pre-formed structure can be evaluated later at room temperature using electron beam imaging, eliminating the need for direct high-temperature measurement.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention creates a copy or imprint of the heat treatment conditions in the form of the step-terrace structure. The contrast information and structural characteristics of the steps and terraces replicate the effects of the heat treatment environment, allowing indirect evaluation of conditions that cannot be directly measured after the treatment is complete.

Inventive Principle:

Principle #26Copying

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

Enables accurate evaluation of the heat treatment environment, independent of crystal defects and subsurface damage, by analyzing brightness information reflecting the stacking direction of atoms on the SiC substrate, thus ensuring consistent reproduction of step-terrace structures.

Implementation Method 1

making an electron beam incident at an incident angle inclined with respect to a normal line of a {0001} plane of a heat-treated silicon carbide substrate

Methodology Applied

Scientific EffectElectron beam diffraction: Diffraction

Implementation Method 2

acquiring an image by making an electron beam incident at an incident angle inclined with respect to a normal line of a {0001} plane

Methodology Applied

Scientific EffectElectron beam scattering: Scattering

Data Source

PatentUS20240020814A1Heat treatment environment evaluation method and silicon carbide substrate

Publication Date: 2024.01.18 TOYOTA TSUSHO CORP

AI summary

An object of the present invention is to provide a novel technique for evaluating a heat treatment environment. The present invention is a method for evaluating a heat treatment environment, the method comprising an image acquisition step of acquiring an image by making an electron beam incident at an incident angle inclined with respect to a normal line of a {0001} plane of a heat-treated silicon carbide substrate and an environment evaluation step of evaluating a heat treatment environment of the silicon carbide substrate on a basis of on contrast information of the image.