Shielding Mesh Inspection for Sample-Side Defect Detection

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Solution Overview

Problem

Existing particle beam devices face challenges in accurately characterizing shielding elements, as defects on the side facing the sample can go undetected, leading to potential damage to the sample due to uncontrolled electric field interactions.

Innovation Solution

A method and means for characterizing the shielding element by positioning a sensor or contact surface on the side facing the sample, allowing for direct and complete characterization of the shielding element's topology and detection of defects, using confocal or interferometric sensors and spring-loaded contact surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the shielding element is positioned close to the sample to limit electric field influence, then the effectiveness of electric field shielding is improved, but the risk of sample damage from defects on the sample side increases

Engineering Contradiction:
Improveelectric field shielding effectivenessVSAvoidsample damage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a preliminary characterization of the shielding element's sample side using optical sensors and simulation models before actual particle beam operation. This allows defects to be detected and accounted for in advance, enabling the shielding element to be positioned close to the sample for effective electric field shielding while preventing sample damage from undetected defects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces optical sensors and simulation models as intermediary means to characterize the shielding element. These intermediaries enable non-contact, high-resolution inspection of the sample side surface topology, allowing defect detection without requiring the shielding element to be removed from its operational position near the sample.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the incidence side of the shielding element is characterized using particle beam, then defects on the incidence side can be detected, but defects on the sample side cannot be accurately analyzed

Engineering Contradiction:
Improvedefect detection accuracy on incidence sideVSAvoidinformation about sample side defects
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent replaces particle beam-based characterization with optical sensor-based characterization for inspecting the shielding element. Optical sensors can access and characterize the sample side directly without requiring particle beam penetration through the shielding element, thereby eliminating the information loss about sample side defects while maintaining high measurement precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

Instead of characterizing the shielding element from the incidence side using particle beams (the conventional approach), the patent inverts the approach by characterizing the sample side directly using optical sensors. This inversion allows direct observation of the previously inaccessible surface, providing complete information about both sides of the shielding element.

Inventive Principle:
Principle #13The other way round (Inversion)

3Loss of information

If optical sensors are used to characterize the sample side of the shielding element, then complete information about the sample side can be obtained, but the device complexity increases

Engineering Contradiction:
Improveinformation completeness about sample sideVSAvoidcharacterization system complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent uses optical sensors to create a digital copy or model of the shielding element's sample side surface topology. This optical copy provides complete information about the sample side without requiring physical access or disassembly, and the data can be integrated with simulation models to achieve comprehensive characterization without proportionally increasing device complexity.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent employs optical sensors that can serve multiple functions: characterizing the shielding element's sample side, verifying positioning accuracy, and detecting defects. This multi-functionality reduces the need for separate characterization systems, thereby minimizing the increase in device complexity while achieving complete information about the sample side.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 reliable detection of defects and anomalies on the shielding element's sample side, preventing damage to the sample by ensuring accurate positioning and contact detection, thereby enhancing the operational safety and effectiveness of particle beam devices.

Implementation Method 1

the sensor comprises a confocal sensor, and the measurement of the topology is at least in part based on a confocal measurement principle

Methodology Applied
Scientific EffectConfocal measurement principle:

Implementation Method 2

the sensor comprises an interferometric sensor, and the measurement of the topology is at least in part based on an interferometric measurement principle

Methodology Applied
Scientific EffectInterferometric measurement principle: Interference

Implementation Method 3

the contact surface is movably coupled to the base along a plane of the contact surface, preferably via a spring element

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4339992A1Mesh integrity check
Publication Date: 2024.03.20 CARL ZEISS SMT GMBH
  • EP4339992A1 patent drawingFigure 1
  • EP4339992A1 patent drawingFigure 2
  • EP4339992A1 patent drawingFigure 3

AI summary

The present application relates to a method for characterizing a shielding element (C) of a particle beam device (100) for shielding an electric field between a sample position and a particle beam source (101). The method comprises positioning a means for characterizing (S1, S2, S3) the shielding element on a side of the shielding element which is facing the sample position.