Wafer Defect Classification Using Extended Bounding Box Dilation
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Solution Overview
Problem
Current methods for identifying defects in semiconductor manufacturing are limited by the coordinate accuracy of inspection tools, which cannot effectively distinguish between defects belonging to 'hot spots' and those that do not, due to the tools' inability to accurately determine the proximity of defects to high-risk areas defined by optical proximity effects.
Innovation Solution
A method involving the creation of an extended bounding box around detected defects, dilation in proportion to the dimensions of the pattern of interest for the closest hot spot, and comparison with the area of interest to classify defects as either hot spot or non-hot spot defects, utilizing improved coordinate accuracy of modern inspection tools.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current methods for identifying defects are used, then the classification process is simple, but the measurement precision of defect position relative to hot spot boundaries deteriorates
Solution Approach 1:
The patent segments the defect classification process into distinct operational phases: creating an extended bounding box around the defect, dilating it to a target size, extracting polygons from design data, and performing systematic comparisons. This segmentation transforms a complex classification problem into manageable discrete steps that can be executed algorithmically with high precision.
Solution Approach 2:
The patent performs preliminary actions by pre-defining hot spot boundaries, creating extended bounding boxes around defects before comparison, and pre-extracting relevant polygons from design data. These preparatory steps ensure that when the actual classification comparison occurs, all necessary information is already organized and ready, enabling high-precision measurement without Rushing through the process.
2Measurement precision
If the coordinate accuracy of inspection tools is improved, then the detection precision increases, but the ability to accurately classify defects relative to hot spot boundaries deteriorates due to negation by current methods
Solution Approach 1:
The patent changes the parameter of comparison from direct coordinate matching to geometric shape and position matching. By transforming the classification criterion into a geometric comparison framework (comparing polygons and their spatial relationships), the system can effectively utilize high coordinate accuracy from modern inspection tools without being constrained by the limitations of previous coordinate-based methods.
3Ease of operation
If a simple bounding box comparison method is used, then the ease of operation is high, but the measurement precision of defect-hot spot relationship deteriorates
Solution Approach 1:
The patent extends the comparison from simple two-dimensional bounding box overlap to a more comprehensive geometric analysis that includes polygon shape matching, orientation, and spatial relationship verification. This dimensional extension in the comparison process maintains operational simplicity through automated algorithmic execution while significantly improving measurement precision of the defect-hot spot relationship.
Data Source
AI summary
Systems and methods for classifying defects on a wafer are provided. One method includes dilating an extended bounding box (EBB) surrounding a defect position on a wafer in two dimensions in proportion to a width and height of a pattern of interest (POI) for a hot spot closest to the defect position. The method also includes determining if polygons in the POI match polygons in the dilated bounding box. If the polygons in the POI do not match the polygons in the dilated bounding box, the defect is classified as a non-hot spot defect. If the polygons in the POI match the polygons in the dilated bounding box, the defect is classified as a hot spot defect if the area of the EBB intersects the area of interest associated with the hot spot and a non-hot spot defect if the EBB area does not intersect the area of interest.