Semiconductor Defect Analysis via Optical Waveform Simulation
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Solution Overview
Problem
Current methods for analyzing defects in semiconductor devices are inefficient in identifying the root cause of defects across multiple process steps, leading to delays in feedback to manufacturing lines and impacting yield.
Innovation Solution
A defect analyzing system that acquires defect position and size data, performs process simulations, and conducts optical simulations to generate waveforms for comparison with real waveforms, calculating a similarity degree to determine if the defect was caused by a specific manufacturing process step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple process steps are inspected to identify defect causes, then defect analysis accuracy is improved, but analysis time and complexity increase
Solution Approach 1:
The system performs preliminary actions by acquiring process step information and simulation conditions in advance, preparing simulation models before actual defect analysis. This allows the system to quickly compare simulated waveforms with measured waveforms without performing full simulations during the analysis phase, thereby improving accuracy while reducing analysis time.
Solution Approach 2:
The system creates copies of the semiconductor device structure through simulation models that replicate the physical device geometry and material properties. By comparing measured waveforms with simulated waveforms from these virtual copies, the system can identify defect causes accurately without physically testing multiple process steps, thus reducing time loss.
2Measurement precision
If detailed process simulation is performed for each process step, then defect cause identification accuracy is improved, but computational complexity increases
Solution Approach 1:
The system segments the defect analysis process into distinct phases: acquiring process step information, setting simulation conditions for each process step, performing simulations, and comparing results. By dividing the complex analysis into manageable segments, the system maintains high accuracy while reducing overall computational complexity through structured processing.
Solution Approach 2:
The system applies local quality by setting specific simulation conditions tailored to each process step's characteristics. Rather than using uniform simulation parameters across all steps, the system adjusts simulation conditions locally for each process step based on its specific properties, improving accuracy while optimizing computational resources.
3Loss of information
If waveform comparison is performed across multiple process steps, then defect source tracing is improved, but measurement and processing time increase
Solution Approach 1:
The system implements feedback by comparing measured waveforms with simulated waveforms and using the comparison results to identify which process step caused the defect. This feedback mechanism allows the system to trace defect sources efficiently by iteratively refining the analysis based on waveform matching, improving tracing accuracy while minimizing measurement and processing time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively identifies the manufacturing process step responsible for defects, enabling timely feedback and improving semiconductor device yield by accurately simulating defect generation and comparing simulated waveforms with real data.
Implementation Method 1
measuring a waveform of reflected light in a region which includes the defect
Data Source
AI summary
A defect analyzing method includes acquiring a position and a size of a defect obtained in a defect inspection of a semiconductor device and a waveform of a reflected light in a region which includes the defect, the waveform being obtained in an optical inspection; acquiring process step information which includes a plurality of process steps to manufacture the semiconductor device and a processing content per the process step; performing a process simulation of the semiconductor device based on the position and the size of the defect and the process step information; performing an optical simulation on a result of the process simulation thereby to generate a waveform of a reflected light; calculating a similarity degree between the acquired waveform of the reflected light and the generated waveform of the reflected light; and judging whether or not the calculated similarity degree exceeds a threshold value registered in advance.