Defect Review Apparatus Using Multiple Light Sources
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional defect review techniques face challenges in accurately correcting coordinate misalignments for unusual defects, such as huge defects and tailing defects, which can result in incomplete capture within the field of view and reliability issues during SEM image acquisition.
Innovation Solution
A defect review apparatus that uses multiple optical microscopes with different light sources and cameras to determine if coordinate misalignment can be corrected, switching to alternative microscopes like halogen bright field or color optical microscopes when necessary to ensure accurate alignment and capture of defects, improving throughput and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single optical microscope is used for coordinate alignment, then the device complexity is reduced, but the measurement precision deteriorates for unusual defects like huge defects and tailing defects
Solution Approach 1:
The patent implements multiple optical microscopes (dark field optical microscope, bright field optical microscope, color optical microscope) within a single defect review apparatus, where each microscope type serves universal coordinate alignment functions but excels with different defect characteristics. This multi-functionality allows the system to handle various defect types including huge defects and tailing defects that cannot be properly aligned with a single microscope type.
2Reliability
If multiple optical microscopes with different light sources are used, then the reliability of defect capture is improved, but the device complexity increases
Solution Approach 1:
The patent assigns specific microscope types to specific defect characteristics: dark field optical microscope for general defects, bright field optical microscope for huge defects, and color optical microscope for tailing defects. This local quality approach ensures that each defect type receives the optimal observation method, thereby improving reliability while managing complexity through targeted specialization rather than universal capability.
Solution Approach 2:
The system dynamically selects which optical microscope to use based on the defect characteristics being observed. The defect review apparatus can switch between different microscope types depending on the specific defect type encountered, allowing the system to adapt its complexity level to the actual observation needs rather than maintaining maximum complexity for all cases.
3Measurement precision
If conventional coordinate alignment methods are used, then the ease of operation is maintained, but the measurement precision deteriorates for unusual defects
Solution Approach 1:
The defect review apparatus automatically determines which optical microscope type is most suitable for observing each defect based on defect characteristics, and automatically performs coordinate alignment using the appropriate microscope. This self-service capability eliminates the need for operators to manually select microscope types and perform different alignment procedures for different defect types, thereby maintaining ease of operation while achieving high measurement precision for unusual defects.
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
This approach enables precise correction of coordinate misalignments for unusual defects, ensuring that all defects are captured within the field of view and improving the reliability of SEM observation by selecting the appropriate optical microscope based on defect features.
Implementation Method 1
Optical inspection apparatus: irradiates light such as laser onto the sample; and detects reflected light or scattered light generated from the sample
Implementation Method 2
Optical inspection apparatus: irradiates light such as laser onto the sample; and detects reflected light or scattered light generated from the sample
Data Source
AI summary
Provided is a defect review technique that can accurately correct coordinate differences with respect to unusual defects in which it is difficult to accurately correct coordinate misalignments by conventional automatic fine alignment. If it is impossible to correct a coordinate misalignment on the basis of a first optical microscope image acquired by a first light source, a defect review apparatus acquires a second optical microscope image using a second light source, and determines whether it is possible to correct the coordinate misalignment on the basis of the second optical microscope image.