Multibeam Charged Particle Scanning for Beam Defect Throughput
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multibeam-type charged particle beam devices, beam defects lead to reduced throughput as the entire scan region needs to be re-scanned with a different beam, resulting in a ½ reduction in inspection speed when a defective beam occurs.
Innovation Solution
A charged particle beam device with a control unit that changes the scanning method to increase the scanning width when a beam defect is detected, allowing for relief scanning using a second method with wider scanning, thereby maintaining throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the scan region is re-scanned with another beam when a defective beam is detected, then the image data can be obtained, but the throughput is reduced to 1/2
Solution Approach 1:
The patent divides the scan region into multiple sub-regions corresponding to each beam's coverage area. When a defect is detected in one beam, only the corresponding sub-region is re-scanned by another beam, rather than re-scanning the entire scan region. This segmentation approach maintains reliability for the affected area while minimizing the impact on overall throughput.
Solution Approach 2:
The patent performs partial action by re-scanning only the necessary sub-region affected by the defective beam, rather than performing excessive full-region re-scanning. This partial action approach ensures that image data is obtained for the affected area while avoiding unnecessary re-scanning of regions already covered by other functional beams, thus maintaining higher throughput.
2Productivity
If multiple beams are used to irradiate the sample, then the inspection speed is improved, but the system becomes more vulnerable to beam defects
Solution Approach 1:
The patent dynamically changes the scanning parameters (scanning width, scan region) based on the detected beam defect. When a defect is detected, the system adjusts the scanning parameters of remaining functional beams to cover the affected area, transforming the static multibeam scanning approach into a dynamic adaptive approach that maintains reliability while preserving inspection speed.
Solution Approach 2:
The patent introduces dynamic adaptability to the multibeam scanning system. The scanning width and scan region are adjusted in real-time based on beam defect detection. This dynamic approach allows the system to maintain high inspection speed by utilizing multiple beams while adapting to reliability issues by redistributing the scanning workload among functional beams.
3Productivity
If the scanning width is increased in the second scanning method, then the throughput is maintained, but the scanning complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where beam defect detection triggers automatic adjustment of scanning parameters. The control unit receives feedback about beam defects and dynamically modifies the scanning width and scan region accordingly. This feedback-based approach manages scanning complexity by automating the parameter adjustment process rather than requiring complex manual control configurations.
Solution Approach 2:
The patent prepares alternative scanning parameters and methods in advance for handling beam defects. The control unit has pre-configured second scanning methods with adjusted scanning widths ready to be activated when defects are detected. This preliminary preparation reduces the complexity of real-time decision-making and parameter adjustment during actual operation.
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
Prevents deterioration in throughput due to beam abnormalities by enabling effective relief scanning, allowing for continued high-speed inspection even with defective beams.
Implementation Method 1
a sample is irradiated with a charged particle beam (hereinafter, referred to as a primary beam) such as an electron beam or an ion beam, a signal of a secondary charged particle (hereinafter, referred to as a secondary beam) such as a generated secondary electron is acquired
Data Source
AI summary
Provided is a charged particle beam device for which deterioration in throughput in the event of abnormality of multiple beams can be prevented. The charged particle beam device includes: a stage 11 on which a sample is mounted; a charged particle optical system configured to irradiate the sample with multiple beams including multiple primary beams; a detector 15 configured to detect secondary beams generated by interactions between the primary beams and the sample and output detection signals; and a control unit 17 configured to control the stage and the charged particle optical system to generate image data based on the detection signals from the detector obtained by scanning the sample with the multiple beams using a first scanning method. The control unit changes, when the abnormality of the multiple beams is detected based on the image data, the multiple beams to scan the sample using a second scanning method, and a scanning width of the multiple beams for scanning the sample is greater in the second scanning method than in the first scanning method.