Sample Lifting Mechanism with Deceleration Wedges for SEM
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In charged particle beam apparatuses, such as SEMs, the sample lifting and lowering mechanism faces challenges in achieving both high rigidity and weight reduction while maintaining accurate positioning and high-speed movement, especially with increasing semiconductor wafer diameters, which complicates the arrangement and reduces operational efficiency due to directional dependence in rigidity.
Innovation Solution
The implementation of a sample lifting and lowering device with independent wedge-type deceleration mechanisms, driven by ultrasonic motors, which are arranged in a circular pattern around the barycenter of the sample stage to minimize directional rigidity dependence and reduce weight, allowing for synchronized operation and reduced load on the driving device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the sample lifting and lowering mechanism is designed with high rigidity to maintain positioning accuracy, then the positioning accuracy is improved, but the weight of the mechanism increases
Solution Approach 1:
The lifting mechanism is divided into multiple independent lifting mechanisms (at least two) that operate in parallel. Each lifting mechanism is driven by a separate ultrasonic motor, allowing the system to distribute the load and reduce the weight of individual components while maintaining overall rigidity through coordinated operation.
Solution Approach 2:
The patent employs ultrasonic motors that operate at high frequency vibrations to achieve motion. The dynamic operation of ultrasonic motors allows for precise positioning with reduced mechanical contact and lower weight compared to traditional motors, while maintaining positioning accuracy through controlled vibration and resonance.
2Productivity
If the sample lifting and lowering mechanism is designed for high-speed movement to improve throughput, then the movement speed is improved, but the positioning accuracy deteriorates
Solution Approach 1:
Ultrasonic motors utilize high-frequency mechanical vibrations to produce motion, enabling both high-speed operation and precise positioning. The dynamic vibration mechanism allows the system to achieve rapid movement when needed while maintaining positioning accuracy through controlled resonance and feedback, resolving the contradiction between speed and precision.
Solution Approach 2:
The patent incorporates feedback control mechanisms that monitor the position and movement of the sample stage. This feedback allows the system to adjust the operation of multiple ultrasonic motors in real-time, ensuring that high-speed movement does not compromise positioning accuracy, and enabling rapid repositioning when required.
3Speed
If the lifting mechanism weight is reduced to improve response speed, then the movement speed is improved, but the rigidity deteriorates
Solution Approach 1:
By dividing the lifting function into multiple independent mechanisms, each with reduced individual weight, the system achieves fast response speed while the collective arrangement of multiple mechanisms maintains overall rigidity. The distributed structure prevents excessive weight in any single component while preserving structural stability through coordinated operation.
4Manufacturing precision
If directional rigidity is increased to improve positioning accuracy, then the positioning accuracy is improved, but the device complexity increases due to arrangement constraints
Solution Approach 1:
The use of multiple independent lifting mechanisms arranged in a distributed configuration allows the system to achieve uniform rigidity in multiple directions without complex mechanical linkages. Each mechanism contributes to overall structural stability, and their coordinated control simplifies the arrangement compared to traditional single-mechanism designs with complex support structures.
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 configuration enables the sample lifting and lowering device to maintain high rigidity with reduced weight, achieving accurate and high-speed movement while minimizing directional rigidity dependence, thus enhancing the operational efficiency and durability under vacuum environments.
Implementation Method 1
the first lifting and lowering mechanism includes a first deceleration mechanism of a wedge type which generates a first drive output obtained by decelerating a first drive input given from the first driving device in a direction different from that of the input
Data Source
AI summary
To realize a sample lifting and lowering device capable of easily responding to increase of a diameter of a sample with light weight and high rigidity as well as with less directional dependence of rigidity as the sample lifting lowering device arranged above a horizontal movement mechanism. The sample lifting and lowering device includes first and second lifting and lowering mechanisms that lift and lower a sample stage to which the sample is fixed, first and second driving devices that drive the first and second lifting and lowering mechanisms to be lifted and lowered individually and a controller that synchronizes lifting/lowering operations of the first and second lifting and lowering mechanisms by the first and second driving devices by first and second control signals, in which the first lifting and lowering mechanism includes a first deceleration mechanism generating a first drive output obtained by decelerating a first drive input given from the first driving device in a direction different from a direction of the input, the second lifting and lowering mechanism includes a second deceleration mechanism generating a second drive output obtained by decelerating a second drive input given from the second driving device in a direction different from a direction of the input, and directions of the first and second drive inputs are different from each other as well as are not on the same straight line.