Bright and Dark Field Data Combination for Semiconductor Defect Detection
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Solution Overview
Problem
Current semiconductor inspection systems face challenges in accurately detecting defects on wafers as design rules shrink, leading to increased noise and nuisance events, which complicates process control and yield optimization, as they struggle to differentiate between relevant and irrelevant defects using single-channel data processing.
Innovation Solution
Combining pixel-level data from both bright field (BF) and dark field (DF) channels of an inspection system and applying a two-dimensional threshold to enhance the signal-to-noise ratio, allowing for more precise defect detection and classification by integrating data from both channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-channel data processing is used, then device complexity is reduced, but measurement precision and defect detection accuracy deteriorate due to increased noise and nuisance events
Solution Approach 1:
The patent combines data from multiple detection channels (bright field and dark field channels) to process defect information. By merging the data streams, the system achieves more accurate defect detection and noise differentiation, resolving the contradiction between processing complexity and measurement precision through multi-channel data integration.
Solution Approach 2:
The patent transitions from single-channel one-dimensional processing to multi-channel two-dimensional data processing. This dimensional expansion allows the system to differentiate between real defects and nuisance events by analyzing patterns across multiple channels simultaneously, thereby improving measurement precision without excessive complexity increase.
2Manufacturing precision
If design rules are shrunk, then manufacturing precision is improved, but measurement precision deteriorates due to increased difficulty in detecting smaller defects
Solution Approach 1:
The patent merges data from multiple detection channels to enhance the signal-to-noise ratio for small defect detection. By combining information from bright field and dark field channels, the system maintains measurement precision even as design rules shrink and defect sizes decrease, overcoming the limitations of single-channel processing for sub-resolution defects.
3Measurement precision
If multiple detection channels are used, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent implements a unified data processing framework that handles multiple detection channels simultaneously. The defect detection algorithm is designed to process data from various channels through a common analytical approach, reducing the overall system complexity while maintaining the measurement precision benefits of multi-channel inspection.
Data Source
AI summary
Various methods, carrier media, and systems for detecting defects on a specimen using a combination of bright field channel data and dark field channel data are provided. One computer-implemented method includes combining pixel-level data acquired for the specimen by a bright field channel and a dark field channel of an inspection system. The method also includes detecting defects on the specimen by applying a two-dimensional threshold to the combined data. The two-dimensional threshold is defined as a function of a threshold for the data acquired by the bright field channel and a threshold for the data acquired by the dark field channel.