Charged Particle Beam Device Observation Assist Screen
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Solution Overview
Problem
Operators of scanning electron microscopes face difficulties in setting optimal electron irradiation conditions, such as electron dose and scan time, due to numerous influencing parameters, leading to inefficient image acquisition and potential charge or contamination issues, especially for inexperienced users.
Innovation Solution
A charged particle beam device with a control unit and display system that provides an observation assist screen to visually set and adjust electron irradiation conditions, including electron dose per pixel, facilitating intuitive parameter adjustments and reducing trial-and-error operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the electron irradiation time per area is increased to acquire high-resolution images with excellent S/N ratio, then the image quality is improved, but the total irradiation time increases and charge or contamination problems occur
Solution Approach 1:
The patent segments the total irradiation process into multiple frames with different electron irradiation amounts per pixel. By dividing the observation into multiple frames and selectively combining them, the system achieves high S/N ratio without requiring excessively long total irradiation time for each individual frame.
Solution Approach 2:
The patent changes the electron irradiation amount per pixel as a parameter across different frames. By varying this parameter and selectively combining frames with appropriate irradiation amounts, the system optimizes both image quality and total irradiation time, preventing charge and contamination issues.
2Measurement precision
If the scan speed is lowered to irradiate the sample for a long time per area, then the image S/N ratio is improved, but the observation efficiency decreases
Solution Approach 1:
The patent divides the observation into multiple frames scanned at different speeds with different electron irradiation amounts. This segmentation allows efficient scanning in some frames while maintaining image quality through selective combination, thereby improving observation efficiency without sacrificing S/N ratio.
Solution Approach 2:
The patent applies partial action by using different electron irradiation amounts in different frames. Some frames use higher irradiation amounts for efficiency while others use lower amounts for quality, and the system selectively combines them to achieve optimal balance between efficiency and image quality.
3Area of stationary object
If the observation magnification is changed to adjust the field of view, then the viewing scope is improved, but the electron density per area changes and image contrast becomes unstable
Solution Approach 1:
The patent compensates for magnification-induced electron density changes by adjusting the electron irradiation amount per pixel parameter. When magnification changes alter the field of view and electron density, the system modifies the irradiation amount to maintain consistent image contrast across different magnifications.
4Manufacturing precision
If multiple parameters including pixel number, scan speed, and irradiation current are adjusted to optimize image quality, then the image resolution is improved, but the device complexity and operator skill requirement increase
Solution Approach 1:
The patent implements automatic control where the system itself adjusts multiple parameters including pixel number, scan speed, and electron irradiation amount based on observation conditions. This self-service approach eliminates the need for operators to manually coordinate multiple parameters, reducing complexity while maintaining high image resolution.
Solution Approach 2:
The patent creates a multi-functional control system that simultaneously manages pixel number, scan speed, irradiation current, and electron irradiation amount. This universal control mechanism handles multiple parameters in an integrated manner, simplifying the operator's task while achieving optimized image resolution.
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
Enables operators to easily and accurately set electron irradiation conditions, improving image quality and reducing the time required to achieve desired high-resolution images while minimizing contamination and charge-related issues.
Implementation Method 1
a detector configured to detect an electron generated by an interaction between the charged particle beam and the sample
Data Source
AI summary
To assist an operator in setting an observation conditions, so as to acquire an image with a desired image quality (such as contrast) in a charged particle beam device without falling into trial and error based on the experience of the operator. Therefore, the charged particle beam device includes a stage 115 on which a sample is placed, a charged particle optical system configured to irradiate the sample with a charged particle beam, detectors 121 and 122 configured to detect an electron generated by an interaction between the charged particle beam and the sample, a control unit 103 configured to control the stage and the charged particle optical system according to an observation condition set by the operator and configured to form an image based on a detection signal from the detectors, and a display 104 configured to display an observation assist screen for setting the observation condition. The control unit displays, on the observation assist screen 401, information 510 related to an irradiation electron amount per pixel irradiated onto the sample by the charged particle optical system under the observation condition.