CD-SEM Image Processing for Critical Dimension Measurement
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Solution Overview
Problem
Conventional semiconductor wafer manufacturing using scanning electron microscopes faces increased complexity and measurement errors due to shrinking integrated circuit sizes, leading to higher costs and longer measurement times, with manual critical-dimension measurements being subjective and prone to inconsistencies.
Innovation Solution
An image-processing method and apparatus that receives CD-SEM images, performs image-sharpening and de-noise processes, edge detection, and connected-component labeling to generate a critical-dimension information table, objectively measuring critical dimensions and reducing noise and measurement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional SEM is used to measure critical dimensions, then measurement capability is provided, but measurement precision deteriorates due to noise and beam slope effects
Solution Approach 1:
The patent introduces an image processing system as an intermediary between the SEM and the measurement analysis. This system includes sharpness filtering to enhance image quality, noise filtering to remove interference, and edge detection to accurately identify pattern boundaries. The processing system mediates the raw SEM image data and transforms it into accurate critical dimension measurements, eliminating the direct impact of noise and beam slope effects on measurement precision.
2Productivity
If integrated circuit size is shrunk to improve production efficiency, then productivity increases, but measurement complexity increases and measurement precision deteriorates
Solution Approach 1:
The patent applies preliminary image processing actions before measurement analysis. The system performs sharpness filtering to pre-enhance image quality, noise filtering to pre-remove interference, and edge detection to pre-identify pattern boundaries. These preliminary actions prepare the image data in advance, ensuring that even shrunk integrated circuit patterns can be measured with high precision without increasing measurement complexity.
3Ease of operation
If manual critical dimension measurement is performed, then measurement flexibility is provided, but measurement precision deteriorates due to subjectivity
Solution Approach 1:
The patent implements an automated image processing system that performs measurement tasks independently without manual intervention. The system automatically applies sharpness filtering, noise filtering, edge detection, and critical dimension calculation algorithms. This self-service approach eliminates human subjectivity while maintaining operational ease, as the automated system consistently applies the same processing steps to all measurements, ensuring both flexibility and precision.
Data Source
AI summary
A method for measuring critical dimension is provided. The method includes the steps of: receiving a critical-dimension scanning electron microscopy (CD-SEM) image of a semiconductor wafer; performing an image-sharpening process and an image de-noise process on the CD-SEM image to generate a first image; performing an edge detection process on the first image to generate a second image; performing a connected-component labeling process on the second image to generate an output image; and calculating a critical-dimension information table of the semiconductor wafer according to the output image.