Backscattered Electron Detection for Heated Sample Imaging

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Solution Overview

Problem

Charged particle beam apparatuses face challenges in generating clear sample images when observing heated samples due to radiant energy emitted from the sample and sample holder, which causes offsets and instability in detection signals, degrading image quality.

Innovation Solution

A charged particle beam apparatus equipped with a detector that identifies and removes the radiant component from the detection signal through processing or selective detection, allowing for the generation of images without the radiant component, thereby improving image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the sample is heated to high temperature for observation, then the sample can be observed in its heated state (enabling observation of thermal processes), but radiant energy is emitted from the sample and sample holder causing large and unstable offsets in the detection signal that degrade or prevent image generation

Engineering Contradiction:
Improvesample temperatureVSAvoiddetection signal quality
Core Design Contradiction:
TemperatureVSMeasurement precision

Solution Approach 1:

The detection signal is segmented into two components: the radiant component (caused by thermal radiation) and the particle signal component (caused by charged particles). The signal processing unit separates these components through signal processing, allowing the radiant component to be identified and removed while preserving the particle signal for image generation. This segmentation enables high-temperature observation without signal degradation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The radiant component is extracted from the detection signal through signal processing. The signal processing unit identifies and separates the radiant component based on its characteristics (such as temporal variation and spectral properties), then removes it from the detection signal before image generation. This extraction eliminates the harmful offset while maintaining the useful particle signal.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If detectors sensitive to electrons are used to observe the sample, then electron detection capability is achieved, but the detectors also detect radiant energy from the heated sample causing the radiant component to contaminate the detection signal

Engineering Contradiction:
Improveelectron detection capabilityVSAvoidradiant energy interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The signal processing unit acts as an intermediary between the detector and the image generation process. It receives the detection signal containing both electron information and radiant component, processes the signal to separate and identify the radiant component, and outputs a cleaned signal for image generation. This intermediary processing eliminates the harmful radiant interference while preserving the useful electron detection capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses feedback from the detection signal characteristics to dynamically adjust the signal processing. The signal processing unit continuously monitors the detection signal, identifies the radiant component based on its temporal and spectral characteristics, and applies appropriate filtering or subtraction techniques. This feedback mechanism ensures effective radiant component removal while maintaining electron detection accuracy throughout the observation process.

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

The solution effectively removes the radiant component from the detection signal, preventing image quality degradation and enabling the generation of clear sample images even under high-temperature conditions.

Implementation Method 1

When the sample is heated, radiant energy (radiant heat) of an extent to be not ignorable is emitted from the sample and a sample holder; that is, a heated subject. The emission of the radiant energy is specifically emission of light (infrared light, visible light, or the like) as an electromagnetic wave.

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP4235732B1Charged particle beam apparatus
Publication Date: 2024.03.20 JEOL LTD
  • EP4235732B1 patent drawingFigure 1
  • EP4235732B1 patent drawingFigure 2
  • EP4235732B1 patent drawingFigure 3~4

AI summary

Light which is radiant energy is emitted from a sample (20) which is heated, and is detected by a backscattered electron detector (36). A detection signal from the backscattered electron detector (36) includes a radiant component. A radiant component removal section (46) extracts the radiant component from the detection signal using a filter, and then removes the radiant component from the detection signal. An optical detector which detects the radiant component may be provided. A divided detector may be provided as the backscattered electron detector (36).