BSE Detector Optical Energy Filtering in Charged Particle Beams
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing charged particle beam devices with small BSE detectors face challenges in incorporating an energy filter due to their compact size, which is necessary for high-resolution imaging of deep structures.
Innovation Solution
Incorporating a fluorescent substance that converts backscattered electrons into light, a light guide element to direct this light to a detector, and a light amount adjuster to control the light received, along with a control unit to manage the light adjuster, enabling an energy filter function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a small BSE detector is used to reduce the distance between the objective lens and sample for high-resolution imaging of deep structures, then measurement precision and imaging resolution are improved, but the ability to incorporate an energy filter is worsened
Solution Approach 1:
The patent introduces a fluorescent substance as an intermediary between the BSE detector and the electron beam. The fluorescent substance converts backscattered electrons into light signals, which are then detected by a photodetector. This intermediary mechanism enables the small BSE detector to achieve energy filtering capability without compromising its compact size, as the fluorescent material can be deposited as a thin layer that does not significantly increase the detector volume.
2Measurement precision
If the distance between the objective lens and sample is reduced to measure fine steric structures, then measurement precision is improved, but the device complexity increases due to the need for precise positioning and small detector placement
Solution Approach 1:
The patent replaces the conventional direct electron detection mechanism with an optical conversion system. By using a fluorescent substance to convert electron interactions into light signals, the system eliminates the need for complex mechanical positioning of the detector at extremely close distances to the sample. The photodetector can be positioned at a standard distance while still achieving high-resolution measurement through the optical signal conversion process.
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 configuration allows for the implementation of an energy filter in small BSE detectors, enhancing the imaging capability of charged particle beam devices by discriminating electron energies and improving image contrast.
Implementation Method 1
a fluorescent substance that converts charged particles generated by irradiation of a sample with a charged particle beam into light
Implementation Method 2
a light guide element for guiding the light from the fluorescent substance to the detector
Data Source
AI summary
Provided is a charged particle beam device that can impart a function of an energy filter to even a small BSE detector. The charged particle beam device includes a fluorescent substance that converts charged particles generated by irradiation of a sample with a charged particle beam into light; a detector that detects the light emitted from the fluorescent substance; a light guide element for guiding the light from the fluorescent substance to the detector; a light amount adjuster that adjusts the amount of light that is received by the detector through the fluorescent substance and the light guide element; and a control unit that controls the light amount adjuster.