Charged Particle Beam Focus and Energy Filter Adjustment
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Solution Overview
Problem
SEM-type inspection/measurement devices in semiconductor manufacturing lines face inefficiencies due to lengthy adjustment times for focus correction and energy filter calibration, which hinder the observation of high-contrast images and reduce production efficiency.
Innovation Solution
A charged particle beam device that performs focus correction and energy filter reference adjustment using information from a single scan, allowing for simultaneous adjustment of the focal position and energy filter settings without changing the energy filter, objective lens, or retarding voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If energy filter reference adjustment is performed at each measurement point to maintain consistent filtering property, then measurement precision is improved, but loss of time increases due to lengthy adjustment procedures
Solution Approach 1:
The patent performs energy filter reference adjustment in advance during a preliminary scan before actual measurement. The control processing unit acquires information from this preliminary scan and completes the reference adjustment, so that when measurement at each point is performed, the adjustment is already done. This eliminates the need for time-consuming adjustments at each measurement point while maintaining precision.
Solution Approach 2:
The patent combines the energy filter reference adjustment process with the focus correction process, both being performed simultaneously using information from the same preliminary scan. This merging of operations reduces the total adjustment time compared to performing them separately at each measurement point.
2Measurement precision
If focus correction and energy filter reference adjustment are performed separately at each measurement point, then measurement precision is maintained, but productivity decreases due to equivalent or longer adjustment time than observation time
Solution Approach 1:
Both focus correction and energy filter reference adjustment are performed in advance during a preliminary scan. The control processing unit uses information from this single preliminary scan to complete both adjustments before actual measurement begins, eliminating the need for repeated adjustments and significantly improving productivity.
Solution Approach 2:
The patent merges focus correction and energy filter reference adjustment into a single integrated process that uses information from one preliminary scan. This combination reduces the total adjustment time to be much shorter than the actual observation time, reversing the conventional situation where adjustment time equals or exceeds observation time.
3Measurement precision
If energy filter adjustment is redone after each focus adjustment, then measurement precision is maintained, but device complexity increases and productivity decreases
Solution Approach 1:
The patent performs both focus correction and energy filter reference adjustment during a single preliminary scan before measurement begins. This preliminary action eliminates the need for repeated adjustments after each focus correction, reducing the number of adjustment cycles and improving productivity while maintaining precision through the use of information from the preliminary scan.
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 stabilizes sample observation without increasing adjustment time, enhancing production efficiency by reducing the time required for adjustments and maintaining image contrast.
Implementation Method 1
a charged particle source that generates a charged particle beam
Implementation Method 2
a focus adjustment unit that adjusts a focal position of the charged particle beam
Implementation Method 3
a deflection unit for scanning the charged particle beam on the sample
Implementation Method 4
a detection unit that detects charged particles generated when the sample is irradiated with the charged particle beam
Implementation Method 5
a detected charged particle selection unit that selects charged particles to be detected by the detection unit
Data Source
AI summary
A charged particle beam device includes a charged particle source that generates a charged particle beam, a focus adjustment unit that adjusts a focal position of the charged particle beam, a deflection unit for scanning the charged particle beam on the sample, a detection unit that detects charged particles generated when the sample is irradiated with the charged particle beam, a detected charged particle selection unit that selects charged particles to be detected by the detection unit, and a control processing unit that makes focus adjustment of the focus adjustment unit and reference adjustment of the detected charged particle selection unit by using information from the detection unit acquired from one scan.