Multi-Beam Charged Particle System Charge Compensation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Multi beam charged particle beam systems face challenges in imaging secondary electrons due to residual charges on the sample surface, which distort the electrostatic extraction field, leading to perturbed imaging and reduced throughput, especially in high-throughput systems where fast realignment of detectors is necessary.

Innovation Solution

A charged particle beam system with a control system that switches between two modes of operation: one for spatially separating and focusing individual beamlets for precise imaging, and another for providing a defocused beam for charge compensation, using a multi aperture plate and deflection systems to adjust beam energy and diameter, ensuring homogeneous charge compensation and maintaining detector alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a flood gun is used for charge compensation by moving the sample between flooding and imaging positions, then charge compensation is achieved, but throughput is reduced due to repeated sample movement

Engineering Contradiction:

Improvecharge compensationVSAvoidthroughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent combines the flood gun and imaging system into a single integrated configuration where both functions share the same sample position and beam path. The multi-beam system allows simultaneous charge compensation and imaging without requiring sample movement between separate positions, thereby maintaining high throughput while achieving effective charge compensation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent enables continuous imaging operation without interrupting the beam path or moving the sample. The flood gun operates concurrently with the imaging beams, allowing charge compensation to occur continuously during the imaging process rather than requiring separate flooding and imaging cycles.

Inventive Principle:

Principle #20Continuity of useful action

2Reliability

If the sample is moved back and forth between flooding and imaging positions, then charge compensation is performed, but imaging speed and throughput are reduced

Engineering Contradiction:

Improvecharge mitigationVSAvoidimaging speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent pre-configures the flood gun to target the same sample position as the imaging beams, eliminating the need for sample repositioning. The system is prepared in advance with all beam paths aligned to the same focal point, allowing immediate switching between modes without movement delays.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If a flood gun is mounted on the chamber lid requiring sample movement for flooding, then charge compensation is possible, but system complexity and operation difficulty increase

Engineering Contradiction:

Improvecharge compensation capabilityVSAvoidoperation simplicity

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent designs the multi-beam system where the same optical path and sample position serve dual purposes: both imaging and charge compensation. The flood gun is integrated into the existing beam path architecture, allowing a single sample position to fulfill multiple functions without requiring separate mounting configurations or complex sample manipulation.

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

This approach enables efficient and high-throughput imaging by maintaining detector alignment and charge compensation, reducing crosstalk and improving imaging quality even with charged samples, while allowing for fast switching between imaging and flooding modes.

Implementation Method 1

the control controls the objective lens to be configured to focus incoming charged particle beamlets in a first plane in a manner that a first region in which a first individual beamlet of the plurality of charged particle beamlets impinges in the first plane is spatially separated from a second region in which a second individual beamlet of the plurality of charged particle beamlets impinges in the first plane

Methodology Applied

Scientific EffectElectrostatic focusing: Electrostatic Lens

Implementation Method 2

electrostatic extraction fields can be used. A homogeneous extraction field can help ensure the imaging of the interaction products, such as secondary electrons, onto individual detectors

Methodology Applied

Scientific EffectElectrostatic extraction: Electrostatic Lens