Charged Particle Beam Inspection Tracking Deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current charged particle beam inspection methods face inefficiencies in throughput due to the need for extensive stage movement and high deflection widths, which result in unnecessary scanning and aberration issues when trying to improve inspection accuracy for ultrafine patterns on semiconductor wafers.
Innovation Solution
A charged particle beam inspection apparatus and method that employs a movable stage with continuous movement and deflection of multiple beams arranged in rows and columns, using tracking deflection and reset techniques to minimize deflection width and prevent overlapping or omission of scan regions, with the combination of numbers N and M having a greatest common divisor to optimize scanning efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple beams are used to scan small regions with step-and-repeat operation, then throughput is improved by simultaneous scanning, but unnecessary time is caused by settling time for each stage movement
Solution Approach 1:
The patent implements continuous stage movement instead of step-and-repeat operation, eliminating the settling time that occurs with each stage stop. The beam scanning continues uninterrupted while the stage moves continuously, maintaining productive action throughout the inspection process and removing idle settling periods between scans
2Productivity
If deflection width is increased to skip already scanned regions, then scanning efficiency is improved, but electron optics aberration increases
Solution Approach 1:
The patent employs dynamic beam deflection that adapts to the continuous stage movement, allowing the beam to track and scan efficiently across moving regions without requiring excessive static deflection width. The deflection system dynamically adjusts to maintain optimal scanning coverage while minimizing aberration effects
3Loss of time
If continuous stage movement is implemented, then settling time is eliminated, but beam deflection control complexity increases
Solution Approach 1:
The patent utilizes feedback control where the beam deflection system receives real-time position information from the continuously moving stage and dynamically adjusts beam positioning accordingly. This feedback mechanism coordinates beam scanning with stage movement, eliminating settling time while maintaining controlled and precise deflection through adaptive response
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 reduces the deflection width of beam deflection, minimizes the influence of electron optics aberration, and enhances the throughput of pattern inspection by allowing continuous scanning without repeating unnecessary regions, thereby improving the accuracy and efficiency of defect detection for ultrafine patterns.
Implementation Method 1
detecting secondary electrons emitted from the substrate to be inspected due to irradiation with the multiple beams
Data Source
AI summary
A charged particle beam inspection apparatus includes a first deflector to deflect N×N′ multiple beams collectively to N×N′ small regions having a size p/M in the first direction and arrayed at the pitch p in the first direction, perform tracking deflection, and re-deflect the multiple beams collectively to next N×N′ small regions away from the N×N′ small regions by N small regions in the first direction, by the stage completes a movement of a distance of N/M×p so as to reset the tracking deflection; and a second deflector to deflect the multiple beams collectively to scan the N×N′ small regions concerned while the tracking deflection is performed.