Charged Particle Beam Fan Control for Vibration-Stable Imaging
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Solution Overview
Problem
The miniaturization of semiconductor circuits leads to increased exhaust heat and vibration/noise from fans, which affects the precision and accuracy of charged particle beam apparatuses like SEMs, causing thermal deformation and resonance issues.
Innovation Solution
A charged particle beam apparatus with a controller that adjusts the rotation speeds of multiple fans based on vibration information from captured images to prevent resonance and maintain temperature stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If fan output and number are increased for heat exhaustion, then temperature control is improved, but vibration and noise increase causing accuracy deterioration
Solution Approach 1:
The patent applies dynamics by making the fan rotation speed adjustable rather than fixed. The control unit dynamically changes the rotation speed of each fan based on real-time temperature measurements from multiple detectors, allowing the system to optimize between heat exhaustion efficiency and vibration/noise generation depending on current thermal conditions
Solution Approach 2:
The patent changes the operational parameters of the fans by independently controlling the rotation speed of each fan individually. Instead of operating all fans at a constant high speed, the system varies the rotation speed parameter of each fan based on localized temperature conditions, thereby reducing overall vibration and noise while maintaining effective heat exhaustion
2Loss of energy
If multiple fans are used for heat exhaustion, then cooling efficiency is improved, but vibration and noise increase
Solution Approach 1:
The patent applies local quality by assigning different rotation speeds to different fans based on their specific operational conditions. Each fan's speed is independently optimized according to the local temperature requirements in its vicinity, allowing the system to maintain cooling efficiency while minimizing the vibration and noise generated by each individual fan
Solution Approach 2:
The system dynamically adjusts the operation of multiple fans based on real-time temperature feedback. The control unit continuously monitors temperature at multiple locations and adjusts each fan's rotation speed accordingly, enabling the system to maintain effective cooling while reducing harmful vibrations and noise by operating fans only at necessary speeds
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 vibration and noise, maintaining apparatus performance and image accuracy by controlling fan rotations to avoid resonance and ensure consistent temperature.
Implementation Method 1
a plurality of air blowers 3 are provided on the body cover 2... The controller 100... controls the numbers of rotations of the plurality of air blowers 3
Implementation Method 2
a microscope 8 that images the sample 15... using an electron microscope to measure the dimension of a circuit
Implementation Method 3
the controller 100 obtains vibration information from the image obtained by imaging the sample 15 by the microscope 8
Data Source
AI summary
To provide a technique of the above charged particle beam apparatus, a technique that can prevent the lowering of apparatus performance due to the influence of vibration and noise by an air blower (fan). The charged particle beam apparatus includes a body device that is provided in a body cover, a plurality of air blowers that are provided on the body cover, and a controller that controls the plurality of air blowers. The body device has a stage on which a sample is placed, and a microscope that images the sample. The controller obtains an image obtained by imaging the sample by the microscope, obtains vibration information from the image, compares the vibration information and a specification value, and on the basis of the result of the comparison, controls the numbers of rotations of the plurality of air blowers. The controller decreases the number of rotations of at least one first air blower among the plurality of air blowers, and increases the number of rotations of at least one different second air blower among the plurality of air blowers.