Charged Particle Beam Magnification Calibration via Field Displacement

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Solution Overview

Problem

Conventional charged particle beam equipment struggles to accurately calibrate magnification and measured length across a range of magnifications using standard dimension specimens, particularly at high or low observation magnifications, and is limited by specimen drift and magnification error variations.

Innovation Solution

The equipment employs a method where the displacement of the field of view is measured before and after beam deflection at different magnifications, allowing for calibration of magnification errors at non-optimal observation magnifications using a single standard specimen, thereby reducing errors and maintaining dimensional accuracy across various magnification ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a standard dimension specimen is used for magnification calibration, then calibration accuracy is improved at optimal observation magnifications, but calibration cannot be performed at high or low magnifications where the specimen features are not observable

Engineering Contradiction:

Improvemagnification calibration accuracyVSAvoidmagnification range coverage

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the parameter of observation magnification to calibrate at multiple magnification levels. By capturing images at both low and high magnifications and using image processing to calculate displacement amounts, the system achieves calibration across the entire magnification range, not just at optimal observation magnifications where standard specimen features are visible.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If multiple standard specimens are used to cover different magnification ranges, then calibration coverage is improved, but device complexity and calibration time increase

Engineering Contradiction:

Improvemagnification range coverageVSAvoidcalibration system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes a single standard dimension specimen serve multiple functions by using it for calibration across the entire magnification range. Through image processing that calculates displacement amounts from images captured at different magnifications, the system eliminates the need for multiple specimens, thereby reducing complexity while maintaining comprehensive calibration coverage.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent creates a virtual copy of the standard specimen's measurement capability through image processing. By processing images captured at different magnifications and calculating displacement amounts, the system effectively replicates the calibration function across magnification ranges where the physical specimen features would normally be unobservable.

Inventive Principle:

Principle #26Copying

3Measurement precision

If conventional magnification calibration is performed, then calibration at specific magnification points is achieved, but magnification error variations between magnification steps are not controlled

Engineering Contradiction:

Improvemagnification calibration accuracyVSAvoidmagnification error consistency

Core Design Contradiction:

Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent implements a feedback mechanism by measuring displacement amounts through image processing and using this information to calculate and control magnification errors. The system captures images at different magnifications, processes them to determine actual displacement, and uses this feedback to correct magnification errors, ensuring consistent accuracy across magnification steps.

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

This approach enables accurate calibration of magnification and measured length at various observation magnifications, including those where standard specimens cannot be used, by compensating for specimen drift and minimizing magnification error variations, thus ensuring consistent dimensional accuracy.

Implementation Method 1

a displacement of a field of view is obtained before and after deflecting a charged particle beam by a beam deflector by a predetermined amount

Methodology Applied

Scientific EffectBeam deflection: Lorentz Force

Data Source

PatentUS8304722B2Charged particle beam equipment and charged particle microscopy

Publication Date: 2012.11.06 HITACHI HIGH TECH CORP

AI summary

On the basis of a displacement of the field of view before and after a deflection of a charged particle beam, extracted from a first specimen image, including a displacement of the field of view recorded by causing a charged particle beam to deflect by a predetermined amount by a beam deflector in an image in which a specimen image is captured at a first magnification calibrated by using a specimen enlarged image of a specimen as a magnification standard, and also a displacement of the field of view before and after a deflection of the charged particle beam, extracted from a second specimen image, including a displacement of the field of view recorded by causing a charged particle beam to deflect by the predetermined amount by the beam deflector in an image in which a specimen image is captured at a second magnification, the second magnification is calibrated.