Stage Device and Charged Particle Beam Device Equipped with the Same
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Solution Overview
Problem
Existing stage devices for scanning electron microscopes face challenges in maintaining positional accuracy due to thermal deformation caused by heat dissipation issues, particularly when using Peltier elements on the moving stage side, which increases the load of radiant heat transfer and introduces time delays in temperature control.
Innovation Solution
A stage device with a comb-like fin configuration and Peltier modules on the stationary side, combined with a control unit for feedback control, reduces the load of radiant heat transfer and maintains uniform temperature distribution across the moving stage, preventing thermal deformation and improving positioning accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a Peltier element is placed on the moving stage side, then the relative positional relation between the Peltier element and the moving stage is fixed, but the load of radiant heat transfer increases
Solution Approach 1:
The patent inverts the conventional arrangement by placing the Peltier element on the stationary side rather than the moving stage side. This inversion reduces the radiant heat transfer load while maintaining temperature control stability through feedback control that adapts to the stage's position.
Solution Approach 2:
The patent implements feedback control where the control unit adjusts the Peltier element's operation based on the stage's position and temperature measurements. This ensures stable temperature control despite the Peltier element being stationary rather than moving with the stage.
2Loss of energy
If comb-like fins are used to increase heat transfer area, then radiant heat transfer efficiency improves, but time delay in temperature control increases
Solution Approach 1:
The patent uses comb-like fins that extend only partially in the stage movement direction, providing sufficient heat transfer area without excessive thermal mass. This partial action approach maintains efficient radiant heat transfer while reducing the time delay associated with heating and cooling the fin structure.
Solution Approach 2:
The patent makes the fin configuration adaptable to the stage's position through feedback control. The system dynamically adjusts which fins are active and their operational characteristics based on real-time position and temperature data, optimizing the balance between heat transfer efficiency and response time.
3Productivity
If the stage moves rapidly, then productivity improves, but temperature uniformity across the stage deteriorates
Solution Approach 1:
The patent employs feedback control that continuously monitors the stage's position and temperature distribution. When the stage moves rapidly, the system adjusts the Peltier element's output and activates specific fins to compensate for thermal gradients, maintaining temperature uniformity despite high-speed movement.
Solution Approach 2:
The patent uses predictive control based on the stage's motion trajectory. The system anticipates temperature changes that will occur during rapid movement and pre-adjusts the cooling configuration, ensuring temperature uniformity is maintained before thermal gradients can develop.
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
The solution effectively reduces the load on cooling systems, prevents thermal deformation, and enhances the positional accuracy of the stage device by maintaining consistent temperature control, even during rapid movements.
Implementation Method 1
a Peltier module is provided between the second fin and the second stage with one heat transfer surface of the Peltier module in contact with the second fin and the other heat transfer surface in contact with the second stage
Implementation Method 2
heat transfer that occurs between the first fin on the first stage side and the second fin by controlling the temperature of the second fin
Implementation Method 3
In JP-2006-351741-A, in order to increase the surface area for radiant heat transfer, fins whose cross sections have comb-like shapes are arranged facing each other, and radiant heat transfer is performed between the two fins
Implementation Method 4
cooling the rear side of the radiation plate by using a Peltier element
Data Source
AI summary
An object is to provide a stage device capable of preventing thermal deformation of a stage and improving positioning accuracy in positioning the stage even in a method in which a Peltier element is arranged on a stage on the stationary side, and a charged particle beam device including the stage device. Provided are a stage device having a first stage that moves linearly, a first fin having a comb-like cross-sectional shape and extending in the linear movement direction of the first stage, a second stage having a second fin disposed opposite the first fin and being stationary in relation to the first stage, a heat transfer mechanism that transfers heat between the first fin and the second fin while maintaining a non-contact relation therebetween, a Peltier module between the second fin and the second stage with one heat transfer surface of the Peltier module in contact with the second fin and the other heat transfer surface in contact with the second stage, and a control unit to control the temperature of the second fin by the Peltier module, and a charged particle beam device including the stage device.