Charged-particle beam device with deflector and energy filter
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Solution Overview
Problem
Scanning electron microscopes face challenges in maintaining stable measurement and inspection results due to electric potential fluctuations in samples, which affect the trajectory of signal electrons and filtering characteristics, leading to reduced contrast and measurement robustness.
Innovation Solution
A charged-particle beam device with a detector, energy filter, deflector, and control device that adjusts the deflection conditions of deflectors based on calculated parameters to compensate for electric potential fluctuations, ensuring stable signal electron trajectories and filtering characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the resolution of energy discrimination is improved, then the contrast of observation unit is improved, but the measurement robustness decreases due to large contrast changes with trajectory changes
Solution Approach 1:
The system uses a feedback mechanism where the control device continuously monitors the trajectory of signal electrons and adjusts the deflector voltage in response to detected trajectory changes. This feedback loop compensates for trajectory deviations caused by observation pattern coordinate changes, maintaining stable measurement conditions while preserving high energy resolution capabilities.
Solution Approach 2:
The invention dynamically changes the voltage parameter applied to the deflector based on detected trajectory variations. By adjusting the deflector voltage in response to trajectory changes, the system maintains stable electron trajectories through the energy filter, thereby preserving measurement robustness while utilizing high energy resolution for improved contrast.
2Stability of the object's composition
If the trajectory of signal electrons is adjusted to compensate for electric potential fluctuation, then the filtering characteristic stability is improved, but the device complexity increases
Solution Approach 1:
The system employs a self-service mechanism where the control device automatically detects trajectory changes and adjusts the deflector voltage without requiring external intervention or complex manual calibration. The system uses its own detector and control mechanisms to maintain stable trajectories, reducing the need for additional external equipment or complex operational procedures.
3Illumination intensity
If a bandpass energy filter with high energy resolution is used, then the contrast is improved, but it becomes difficult to implement stable observation when trajectory is not compensated
Solution Approach 1:
The system performs preliminary trajectory compensation by proactively adjusting the deflector voltage before trajectory deviations significantly impact the observation. The control device anticipates trajectory changes and applies corrective voltage adjustments in advance, ensuring that the high-resolution bandpass filter continues to receive electrons on stable trajectories, thereby maintaining both high contrast and observation stability.
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 stable and accurate measurements and inspections by maintaining consistent signal electron trajectories and filtering characteristics, even with fluctuating sample potentials, thereby improving reproducibility and contrast in SEM observations.
Implementation Method 1
a deflector that deflects the charged particles emitted from the sample towards the energy filter
Implementation Method 2
an energy filter that filters energy of the charged particles emitted from the sample
Data Source
AI summary
The purpose of the present invention is to provide a charged-particle beam device capable of stable performance of processes such as a measurement or test, independent of fluctuations in sample electric electric potential or the like. To this end, this charged-particle beam device comprises an energy filter for filtering the energy of charged particles released from the sample and a deflector for deflecting the charged particles released from the sample toward the energy filter. A control device generates a first image on the basis of the output of a detector, adjusts the voltage applied to the energy filter so that the first image reaches a prescribed state, and calculates deflection conditions for the deflector on the basis of the post-adjustment voltage applied to the energy filter.