Multilayer Scintillator for Charged Particle Signal Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional charged particle detection systems struggle to distinguish and separate signals from secondary electrons (SEs) and backscattered electrons (BSEs) effectively, leading to mixed images and reduced contrast, which complicates the analysis of specimen layers and increases measurement time and errors.
Innovation Solution
A multilayer scintillator assembly with at least two active layers tuned to attract and separate charged particles by their energy levels, generating distinct wavelengths of photons that are then separated using a beam splitter, allowing for simultaneous imaging and processing of SE and BSE signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional single-layer scintillator detectors are used to detect charged particles, then the detection system is simple in structure, but the system cannot effectively distinguish and separate signals from secondary electrons (SEs) and backscattered electrons (BSEs), resulting in mixed images and reduced measurement precision
Solution Approach 1:
The scintillator detector is divided into multiple layers (first scintillator layer and second scintillator layer), where each layer detects different types of charged particles based on their energy levels. The first layer detects lower energy SEs while the second layer detects higher energy BSEs, enabling signal separation and improving measurement precision without requiring complex external separation systems.
Solution Approach 2:
The patent introduces an energy dimension by using multiple scintillator layers with different energy thresholds. Instead of trying to separate particles in spatial dimension with complex optics, the solution uses the energy dimension naturally present in the particle beam, where SEs and BSEs have distinct energy ranges that can be detected by different layer depths.
2Productivity
If conventional discrete detection events (grabs) are used for different particle types, then the detection system is simple to operate, but the total measurement time increases and system drift occurs between sequential measurements
Solution Approach 1:
The multilayer scintillator assembly enables continuous simultaneous detection of both SEs and BSEs in a single grab operation. Both particle types are detected at the same time through their respective layers, eliminating the need for sequential grabs and thereby reducing total measurement time while preventing system drift between measurements.
3Measurement precision
If sequential detection of SEs and BSEs in separate grabs is performed, then the detection system requires minimal components, but system drift occurs between grabs and measurement accuracy decreases
Solution Approach 1:
The scintillator is segmented into multiple functional layers that simultaneously detect different particle types. This internal segmentation allows both SE and BSE signals to be captured in the same measurement window, eliminating temporal drift between sequential grabs and improving overlay measurement accuracy without adding complex external drift compensation systems.
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 precise decoupling and simultaneous imaging of SE and BSE information, improving measurement precision, accuracy, and throughput by distinguishing image information from different layers within a single grab, reducing system drift and enhancing overlay measurement performance.
Implementation Method 1
Scintillators may be deployed in the charged particle detectors to transfer charged particle energy into a plurality of photons with a specific wavelength
Data Source
AI summary
A scintillator assembly including an entrance surface for receiving charged particles into the scintillator assembly, the charged particles including first charged particles at a first energy level and second charged particles at a second energy level. A first scintillator structure configured for receiving the first charged particles and generating a corresponding first signal formed of first photons with a first wavelength of λ1, a second scintillator structure configured for receiving the second charged particles and generating a corresponding second signal of second photons with a second wavelength of λ2, and an emitting surface for egress of a combined signal from the scintillator assembly, the combined signal including the first and second photons, and at least one beam splitter for receiving the combined signal and separating the combined signal to first and second photons.