Microscopic Linewidth Measurement via Image Subtraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Microscopic imaging methods for linewidth measurement are limited by the diffraction limit, leading to low accuracy and difficulties in precise step edge positioning, especially due to issues with uneven illumination and noise.
Innovation Solution
A method involving a high-precision displacement platform to move the sample, acquire two microscopic images, subtract light intensities to obtain a differential image, and perform data fitting using a Gaussian function to locate accurate pulse positions, thereby achieving high-precision linewidth measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional microscopic imaging method is used for linewidth measurement, then measurement speed is high and cost is low, but measurement accuracy is limited by diffraction limit
Solution Approach 1:
The patent segments the measurement process into multiple discrete steps: acquiring first and second images at different positions, performing subtraction to obtain differential image, and then analyzing the differential image for edge positioning. This segmentation transforms a single complex high-precision measurement into a sequence of simpler operations, each contributing to the final accuracy while maintaining overall system simplicity.
Solution Approach 2:
The patent introduces a temporal dimension by acquiring images at different positions (first position and second position) rather than attempting to measure everything in a single static image. The subtraction operation then extracts differential information that highlights edge positions, effectively using the dimension of positional change to overcome the diffraction limit in the spatial dimension.
2Loss of time
If threshold setting method is used for edge position acquisition, then measurement process is simple, but measurement time is long due to multiple scanning requirements
Solution Approach 1:
The patent performs preliminary actions by acquiring two complete images at different positions before any edge detection or measurement calculations are performed. These pre-acquired images contain all necessary information for subsequent differential analysis, eliminating the need for multiple scanning operations and threshold adjustments during the measurement process, thereby reducing total measurement time while maintaining precision.
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 approach enhances measurement accuracy by converting linewidth measurement into differential pulse distance measurement, eliminating the impact of diffraction limits and noise, while maintaining high speed and non-destructive measurement capabilities.
Implementation Method 1
microscopic non-destructive measurement method of a microstructure linewidth based on a translation difference
Implementation Method 2
data fitting is performed on the differential image, and a high-precision sample linewidth measurement result is obtained by using the characteristic of a high differential pulse positioning resolution
Data Source
AI summary
The present disclosure discloses a microscopic non-destructive measurement method of a microstructure linewidth based on a translation difference, based on a conventional microscopic imaging method, a high-precision displacement platform is used to move a to-be-measured sample, one microscopic image of the sample is acquired before and after the displacement separately, subtraction is performed on the two image to obtain a differential image, a light intensity distribution function of the differential image is derived, data fitting is performed on the differential image, and a high-precision sample linewidth measurement result is obtained by using the characteristic of a high differential pulse positioning resolution. The linewidth measurement method of the present disclosure retains the advantages of intuitiveness, quickness, and non-destructive measurement of the microscopic imaging method, breaks through the microscopic imaging diffraction limit, and reducing the impact of uneven illumination and imaging system noise, thereby improving the linewidth measurement accuracy