Multi-Electrode Deflector for Electron Beam Alignment
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Solution Overview
Problem
Current pattern inspection apparatuses for semiconductor wafers face challenges in accurately detecting ultrafine pattern defects due to the miniaturization of LSI patterns, requiring highly accurate and compact mechanisms for separating and guiding multiple electron beams while minimizing aberration and positional deviations.
Innovation Solution
A deflector for multiple electron beams is designed with a configuration of electrode substrates arranged in orthogonal planes to surround the beam path, enabling alignment deflection, scan cancellation, astigmatism correction, and focus correction, allowing for efficient guiding of secondary electron beams to a detector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple primary electron beams and multiple secondary electron beams are separated using a Wien filter, then beam separation is achieved, but additional operations are required for guiding beams to detector and correcting positional deviations
Solution Approach 1:
The patent combines multiple deflection functions (alignment deflection, scan cancellation, astigmatism correction, focus correction) into a single deflector device with multiple electrode substrates. This merging approach eliminates the need for separate mechanisms for each function, reducing overall device complexity while maintaining the required measurement precision for pattern defect detection
Solution Approach 2:
The deflector is designed as a multi-functional device that simultaneously performs alignment deflection, scan cancellation, astigmatism correction, and focus correction. This universal approach allows a single device to handle multiple beam guidance tasks that would traditionally require separate components, thereby reducing complexity while preserving detection accuracy
2Measurement precision
If additional operations are performed for guiding multiple secondary electron beams to detector, then beam guidance is achieved, but mechanism size increases
Solution Approach 1:
Multiple deflection functions are integrated into a single compact deflector structure with electrodes arranged in orthogonal planes. This consolidation reduces the total space required compared to having separate mechanisms for alignment, scan cancellation, astigmatism correction, and focus correction, thereby reducing the area occupied by the deflector mechanism
3Manufacturing precision
If multiple electrode substrates are arranged in orthogonal planes to surround beam path, then alignment deflection and astigmatism correction are improved, but device complexity increases
Solution Approach 1:
The deflector is segmented into multiple electrode substrates (first, second, third, fourth, fifth, sixth, seventh, and eighth electrodes) arranged in orthogonal planes. Each electrode substrate contributes to specific deflection functions, allowing precise beam control through distributed functionality. This segmentation enables high manufacturing precision while managing complexity through modular electrode design
Solution Approach 2:
The patent introduces a three-dimensional orthogonal arrangement of electrode substrates surrounding the beam path. This spatial dimensionality allows multiple deflection functions to be achieved simultaneously in different planes, improving beam alignment precision while organizing complexity through systematic spatial distribution of electrodes
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
The solution enables precise detection of secondary electron beams, improving the accuracy of pattern inspection by reducing aberration and positional deviations, thus enhancing the yield in LSI manufacturing by accurately identifying defects in ultrafine patterns.
Implementation Method 1
a first electrode substrate, second to fourth electrode substrates disposed in order in parallel to each other in a first same plane which is orthogonal to a substrate surface of the first electrode substrate, a fifth electrode substrate disposed opposite to the first electrode substrate, and sixth to eighth electrode substrates disposed in order in parallel to each other in a second same plane such that they are opposite to the second to fourth electrode substrates
Data Source
AI summary
A deflector for multiple electron beams includes a first electrode substrate, second to fourth electrode substrates disposed in order in parallel to each other in a first same plane which is orthogonal to the substrate surface of the first electrode substrate, a fifth electrode substrate disposed opposite to the first electrode substrate, and sixth to eighth electrode substrates disposed in order in parallel to each other in a second same plane such that they are opposite to the second to fourth electrode substrates, wherein the first to eighth electrode substrates are disposed such that they surround a space through which multiple electron beams pass.