Dynamic Defect Review Apparatus for Semiconductor Wafer Inspection
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Solution Overview
Problem
Current defect review methods in semiconductor manufacturing are inefficient due to high image obtaining times and low throughput, primarily because they rely on fixed image acquisition conditions that do not account for varying defect sizes and coordinates, leading to inaccuracies and prolonged processing times.
Innovation Solution
A method and apparatus that dynamically select and adjust image acquisition conditions, such as frame addition amounts and image sizes, to optimize defect image acquisition and detection, allowing for parallel processing of multiple conditions to achieve high defect detection accuracy while reducing overall processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fixed image acquisition conditions are used for defect review, then the review process is simple and fast, but defect detection accuracy decreases due to margin of error in defect coordinates
Solution Approach 1:
The patent applies dynamics by making the image acquisition conditions adjustable and adaptable rather than fixed. The system dynamically selects from multiple predetermined conditions (different magnifications, image sizes, and frame addition amounts) based on the specific defect characteristics being reviewed, allowing optimal balance between detection accuracy and processing time for each defect case
Solution Approach 2:
The patent changes physical parameters of image acquisition by providing multiple predetermined conditions with different magnifications, image sizes, and frame addition amounts. The review apparatus selects appropriate parameters based on defect size and coordinates, thereby optimizing both detection accuracy and processing efficiency without using fixed conditions
2Measurement precision
If high-resolution imaging is performed at defect coordinates with margin of error, then defect type discrimination is accurate, but the field of view may miss the actual defect position
Solution Approach 1:
The system dynamically adjusts the field of view and magnification based on the defect coordinates and their associated margin of error. When margin of error is larger, the system selects conditions with larger field of view to ensure defect capture, while maintaining high-resolution capability when coordinates are more precise
Solution Approach 2:
The patent applies local quality by providing different image acquisition conditions for different defect cases. Each defect is reviewed with locally optimized parameters (magnification, field of view, frame addition) matched to its specific characteristics, rather than applying uniform high-resolution imaging to all defects
3Measurement precision
If multiple images are acquired and averaged to improve signal-to-noise ratio, then defect detection accuracy increases, but processing time increases
Solution Approach 1:
The patent applies partial action by selectively using frame addition (multiple image averaging) only when necessary for specific defect types or conditions. The system chooses from multiple predetermined conditions with different frame addition amounts, using higher frame addition only when defect detection requires enhanced signal-to-noise ratio, thereby balancing accuracy with throughput
4Quantity of substance
If the number of defects to be reviewed per wafer increases due to larger wafer diameters, then production capacity increases, but review throughput decreases due to lower review apparatus speed
Solution Approach 1:
The system dynamically selects from multiple predetermined image acquisition conditions optimized for different defect scenarios. This allows the review apparatus to process defects more efficiently by using appropriate magnification and frame addition levels rather than always using maximum resolution, thereby increasing throughput while handling larger numbers of defects per wafer
Data Source
AI summary
A method for reviewing defect, comprising the steps of: as an image acquisition step, imaging a surface of a sample using arbitrary image acquisition condition selected from a plurality of image acquisition conditions and obtaining a defect image; as a defect position calculation step, proceeding the defect image obtained by the image acquisition step and calculating a defect position on the surface of the sample; as a defect detection accuracy calculation step, obtaining a defect detection accuracy of the defect position calculated by the defect position calculation step; and as a conclusion determination step, determinating whether the defect detection accuracy obtained by the defect detection accuracy calculation step meets a predetermined requirement or not; wherein until it is determined that the defect detection accuracy obtained by the defect detection accuracy calculation step meets a predetermined in the conclusion determination step, the image acquisition condition is selected from the plurality of image acquisition conditions once again and the image acquisition step, the defect position calculation step, the defect detection accuracy calculation step and the conclusion determination step are repeated.