Dual-Sensitivity Defect Inspection for Semiconductor Noise Reduction
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Solution Overview
Problem
Conventional defect inspection algorithms in semiconductor manufacturing face challenges in detecting defects due to noise variations from adjacent patterns, leading to weak detection signals and incorrect identification of defects of interest.
Innovation Solution
A defect inspection method that employs first and second inspection conditions with different sensitivities to capture images of the same detection region, allowing for the comparison of detection signal values to accurately detect defects while minimizing false positives from noise variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional defect inspection algorithms compare reference images and object images obtained from repetitive patterns, then defect detection can be performed, but detection signals become weak due to noise variations from adjacent patterns and underlying layers
Solution Approach 1:
The inspection process is segmented into multiple passes, each capturing images under different inspection conditions (different sensitivities). By dividing the inspection into separate stages with varying parameters, the system can isolate defect signals from noise variations that are consistent across different conditions.
Solution Approach 2:
The inspection conditions are dynamically adjusted between different passes, varying sensitivity levels to capture the same detection region under different parameters. This dynamic variation allows the system to distinguish between static noise patterns and actual defects that respond differently to changing inspection conditions.
2Measurement precision
If multiple inspection conditions with different sensitivities are employed to capture images of the same detection region, then defect detection precision is improved, but inspection process complexity increases
Solution Approach 1:
The same inspection apparatus performs multiple functions by capturing images under different inspection conditions during separate passes. The system uses a universal imaging mechanism that can operate under varying sensitivity levels, eliminating the need for multiple specialized devices while maintaining high defect detection precision.
Solution Approach 2:
The inspection process changes physical parameters (sensitivity levels) between different passes while using the same detection region. By varying inspection parameters rather than device complexity, the system achieves improved precision through parameter diversity rather than structural complexity.
Data Source
AI summary
In a defect inspection method, first and second inspection conditions having a first sensitivity of detection signal and having a second sensitivity of a detection signal for a defect of interest (DOI), respectively, are determined. The first and second sensitivities are different. First and second images of the same detection region on a substrate surface under the first and second inspection conditions respectively, are obtained. The first and second images are matched to detect a defect in the detection region.