Exposure Apparatus Structural Vibration Control at Low-Frequency Modes
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Solution Overview
Problem
Existing systems for controlling vibration in lithography exposure apparatuses are limited by the need for manual adjustment of passive mass dampers and are often ineffective due to space constraints, particularly at low-frequency vibration modes.
Innovation Solution
A method and system that use sensors to receive position data of structural elements, determine position error signals, apply phase correction, and generate force commands to actuate dampers, thereby actively controlling and reducing vibrations at specified frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If passive mass dampers are used to control vibration, then vibration reduction is achieved, but manual adjustment is required and space constraints limit effectiveness
Solution Approach 1:
The active vibration control system automatically detects and counteracts vibrations without manual intervention. Sensors continuously monitor structural element positions, the controller processes this data to determine position error signals, and actuators automatically apply corrective forces to damp vibrations at specified frequencies, making the system self-regulating and eliminating the need for manual adjustment of passive dampers
Solution Approach 2:
The patent replaces passive mechanical mass dampers with an active control system that uses sensors, electronic controllers, and actuators. This substitution transforms the vibration control approach from passive mechanical damping to active electronic control, enabling automatic operation and more effective vibration reduction without space constraints
2Object-affected harmful factors
If passive mass dampers are used to control vibration, then vibration reduction is achieved, but space constraints within the machine limit effectiveness
Solution Approach 1:
The patent replaces bulky passive mass dampers with a compact active control system consisting of sensors, electronic controllers, and actuators. This substitution dramatically reduces the space required for vibration control while maintaining or improving effectiveness, as the active system can apply precise forces without requiring large physical mass elements
3Object-affected harmful factors
If active vibration control is implemented, then vibration reduction effectiveness is improved, but system complexity increases
Solution Approach 1:
The active vibration control system uses sensors to continuously monitor structural element positions, feeds this information back to a controller, and automatically adjusts actuator forces to maintain optimal vibration damping. This closed-loop feedback control enables effective vibration reduction while managing system complexity through automated regulation rather than complex mechanical designs
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 system effectively reduces vibration magnitudes and settling times of structural elements, improving substrate positioning accuracy and throughput in lithography exposure apparatuses.
Implementation Method 1
determine a force command to damp a specified vibration mode frequency of the structural element... such that the actuator applies force to the structural element and damps vibration of the structural element at least at the specified vibration mode frequency
Data Source
AI summary
A method of controlling vibration of a structural element of an exposure apparatus includes receiving data of a position of the structural element, determining a position error signal based at least in part on the position data and a specified position of the structural element, determining a force command to damp a specified vibration mode frequency of the structural element based at least in part on the position error signal and the specified vibration mode frequency, and transmitting the force command to an actuator such that the actuator applies force to the structural element and damps vibration of the structural element at least at the specified vibration mode frequency of the structural element.