Dynamic Band Contrast Imaging for Defect Observation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electron channeling contrast imaging (ECCI) is time-consuming and requires specialized hardware, as it necessitates tilting the sample into the Bragg condition for each grain, making it inefficient for observing defects in multiple grains and prone to radiation damage.
Innovation Solution
A method for generating a dynamic band contrast image (DBCI) using charged particle beams, which constructs images by scanning multiple locations, forming scattering patterns, determining diffraction band locations, and integrating signals along selected diffraction bands without tilting the sample, allowing for quick and reliable defect observation with reduced radiation damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sample is tilted into the Bragg condition for each grain to achieve electron channeling contrast imaging, then defect observation capability is improved, but imaging time and operational complexity increase significantly
Solution Approach 1:
The patent replaces the mechanical sample tilting system with a computational approach. Instead of physically tilting the sample to achieve Bragg diffraction conditions, the method uses electron backscatter diffraction (EBSD) to determine crystal orientations and then computationally processes the backscattered electron signals to generate dynamic band contrast images, eliminating the need for mechanical tilting operations.
Solution Approach 2:
The patent performs preliminary EBSD measurements to determine the crystal orientation of each grain before generating the dynamic band contrast images. This preliminary action allows the system to pre-calculate the appropriate diffraction vectors and channeling conditions for each grain, enabling rapid image generation without time-consuming mechanical tilting during the actual imaging process.
2Measurement precision
If the sample is tilted into the Bragg condition for each grain to achieve electron channeling contrast imaging, then defect observation capability is improved, but device complexity and hardware requirements increase
Solution Approach 1:
The patent replaces the mechanical sample tilting system with a computational approach. Instead of physically tilting the sample to achieve Bragg diffraction conditions, the method uses electron backscatter diffraction (EBSD) to determine crystal orientations and then computationally processes the backscattered electron signals to generate dynamic band contrast images, eliminating the need for mechanical tilting operations.
Solution Approach 2:
The patent makes the imaging system universal by enabling defect observation in multiple grains with different orientations using the same fixed-sample configuration. The system can adapt to any crystal orientation by computationally determining the appropriate diffraction vectors and processing channels, making the system versatile without requiring specialized tilting hardware for each grain type.
3Measurement precision
If conventional ECCI imaging with sample tilting is used, then channeling information is obtained, but radiation damage to the sample increases
Solution Approach 1:
The patent performs preliminary EBSD measurements to determine crystal orientations, then uses this information to guide the acquisition of backscattered electron signals. This preliminary characterization allows the system to optimize the imaging process by selecting appropriate processing channels and parameters, reducing the total beam exposure time required to obtain high-quality channeling information and thereby minimizing radiation damage.
Solution Approach 2:
The patent replaces the mechanical sample tilting system with a computational approach. Instead of physically tilting the sample to achieve Bragg diffraction conditions, the method uses electron backscatter diffraction (EBSD) to determine crystal orientations and then computationally processes the backscattered electron signals to generate dynamic band contrast images, eliminating the need for mechanical tilting operations.
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 efficient observation of sample defects with low radiation damage by constructing DBCIs from the same set of acquired scattering patterns, reducing the duration and complexity of data acquisition and minimizing sample exposure.
Implementation Method 1
forming a plurality of scattering patterns with charged particles emitted from the sample
Implementation Method 2
determining a location of a diffraction band in the plurality of scattering patterns
Data Source
AI summary
Dynamic band contrast image (DBCI) is constructed with scattering patterns acquired at multiple scanning locations of a sample using a charged particle beam. Each pixel of the DBCI is generated by integrating the corresponding scattering pattern along a diffraction band. The DBCI includes charged particle channeling condition and can be used for detecting sample defects.