Guided Wafer Inspection via Spatial Density Analysis
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Solution Overview
Problem
The challenge in semiconductor wafer inspection is the inefficiency in identifying actual defects among numerous potential defects, leading to excessive time consumption and uneven distribution of defect analysis, which results in incomplete defect information.
Innovation Solution
A guided inspection system utilizing spatial density analysis to iteratively select subsets of candidate samples for review based on the locations of previously reviewed samples, ensuring even distribution across the wafer, thereby optimizing the defect review process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If detailed inspection of all candidate samples is performed, then defect detection completeness is improved, but time consumption increases
Solution Approach 1:
The patent applies partial action by selecting and inspecting only a subset of candidate samples rather than all samples. The system identifies representative samples based on spatial distribution criteria and inspects only those, achieving adequate defect detection with reduced time consumption.
Solution Approach 2:
The patent segments the candidate samples into different spatial regions and selects representative samples from each region. This segmentation approach ensures comprehensive coverage across the wafer surface while reducing the total number of samples requiring detailed inspection.
2Reliability
If uniform distribution of inspected samples across the wafer is achieved, then defect analysis representativeness is improved, but selection complexity increases
Solution Approach 1:
The patent applies local quality by ensuring that each spatial region of the wafer has appropriate sample representation. The system evaluates spatial distribution characteristics and adjusts sample selection to achieve uniform coverage across different locations, with each location having the appropriate density of inspected samples.
3Loss of information
If the number of reviewed samples is increased, then defect information completeness is improved, but processing efficiency decreases
Solution Approach 1:
The patent determines an optimal number of samples to review based on statistical criteria rather than reviewing all candidate samples. This partial action approach achieves sufficient defect information completeness while maintaining high processing efficiency by avoiding unnecessary inspections.
Data Source
AI summary
Samples at a semiconductor wafer that have been reviewed by a review tool may be identified. Furthermore, a candidate sample at the semiconductor wafer that has not been reviewed by the review tool may be identified. A location of the candidate sample at the semiconductor wafer may and a number of the samples that have been reviewed that are at locations proximate to the location of the candidate sample may be determined. The candidate sample may be selected for review by the review tool based on the number of the plurality of samples that are at locations proximate to the location of the candidate sample.