SEM Charging Artifact Reduction via Bidirectional Scan Composite
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Solution Overview
Problem
Scanning electron microscopy images often suffer from dynamic charging artifacts such as streaking and non-uniformity, which reduce image quality and accuracy, and existing methods to mitigate these issues require trial and error to optimize imaging conditions.
Innovation Solution
A scanning electron microscopy system and method that acquires multiple images from a sample in different scan directions and combines them to generate a composite image, reducing or eliminating charging artifacts by identifying and removing portions associated with dynamic charging through gradient maps and image reconstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If imaging conditions are adjusted to mitigate dynamic charging artifacts, then charging artifacts are reduced, but image quality characteristics such as resolution and detail may be compromised
Solution Approach 1:
The patent segments the image acquisition process by capturing multiple images with different scan directions (e.g., forward and backward scans). Each individual image contains charging artifacts, but by dividing the overall imaging task into multiple directional passes, the system can later reconstruct a composite image that eliminates artifacts while preserving quality.
Solution Approach 2:
The patent merges multiple images acquired in opposite scan directions to create a composite image. By combining the forward scan image and backward scan image, the system leverages the fact that charging artifacts appear with opposite polarities in each direction, allowing them to cancel out in the composite while the true sample features are reinforced.
2Object-affected harmful factors
If trial and error optimization is used to minimize dynamic charging, then charging artifacts are reduced, but time and complexity increase
Solution Approach 1:
The patent performs preliminary action by acquiring images in multiple scan directions from the outset, rather than attempting to optimize imaging conditions through trial and error. This preliminary multi-directional capture strategy ensures that sufficient data is collected to reconstruct an artifact-free composite image without requiring iterative condition optimization.
Solution Approach 2:
The system uses feedback by analyzing the characteristics of images acquired in different scan directions and using this information to reconstruct the composite image. The reconstruction process incorporates feedback from the individual scan images to eliminate charging artifacts, creating a self-correcting system that reduces artifacts without manual optimization.
3Object-affected harmful factors
If back scatter mode is used to reduce dynamic charging artifacts, then charging artifacts are minimized, but measurement of secondary electrons is avoided reducing image detail
Solution Approach 1:
The patent segments the detection process by separating the acquisition of secondary electron information from the measurement process. Multiple images are captured in standard mode to preserve secondary electron detail, then processed through segmentation by scan direction to isolate and eliminate charging artifacts in the composite reconstruction.
Solution Approach 2:
The patent converts the harmful charging artifacts into a beneficial feature by exploiting their directional dependence. The artifacts that normally degrade image quality are transformed into useful information, as their opposite polarity in forward and backward scans provides the feedback needed for artifact elimination through composite reconstruction.
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 approach results in images with reduced or eliminated charging artifacts, providing a more accurate representation of the sample by minimizing streaking and non-uniformity, thus enhancing image quality and accuracy without the need for trial-and-error optimization.
Implementation Method 1
a scanning electron microscopy sub-system configured to acquire a plurality of images from a sample
Data Source
AI summary
A scanning electron microscopy system for mitigating charging artifacts includes a scanning electron microscopy sub-system for acquiring multiple images from a sample. The images include one or more sets of complementary images. The one or more sets of complementary images include a first image acquired along a first scan direction and a second image acquired along a second scan direction opposite to the first scan direction. The system includes a controller communicatively coupled to the scanning electron microscopy sub-system. The controller is configured to receive images of the sample from the scanning electron microscopy sub-system. The controller is further configured to generate a composite image by combining the one or more sets of complementary images.