Hanging Sensor Support for Lithography Vibration Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional exposing apparatuses face challenges in maintaining high rigidity while reducing weight, leading to increased vibration influence on the projection optical system, which affects exposure precision and complicates assembly and maintenance, especially in immersion type systems where liquid supply vibrations are transmitted to the optical system.
Innovation Solution
The apparatus employs a soft structure support mechanism that separates the sensor and liquid supply devices from the projection optical system, using hanging members to reduce vibration transmission and enhance vibration isolation, allowing for a lightweight and cost-effective setup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a parallel link mechanism with multiple extendable rods is used to support the stage, then the weight of the mechanism portion is reduced and control precision of the moving stage is enhanced, but the structure of the mechanism portion becomes complicated and positioning control during acceleration and deceleration becomes complicated
Solution Approach 1:
The support mechanism is divided into multiple independent rods that can extend and contract separately. Each rod acts as an independent support element, allowing the overall structure to be lighter while maintaining stability through coordinated operation of multiple segments. This segmentation enables weight reduction without requiring a single complex rigid structure.
Solution Approach 2:
The parallel link mechanism employs dynamically adjustable rod lengths that can extend and contract during operation. This dynamic adjustment capability allows the mechanism to adapt its configuration during acceleration and deceleration phases, maintaining positioning precision while using a lighter, more flexible structure compared to fixed rigid supports.
2Stability of the object's composition
If the sensor and projection optical system are integrally supported using a high rigidity support member, then the positional relationship is maintained, but vibration from the floor or irradiation heat causes the positional relationship to vary beyond the permissible range
Solution Approach 1:
The sensor is extracted from the projection optical system and mounted on a separate stage. This physical separation allows the sensor to be isolated from vibrations and heat generated by the projection optical system, while the overhead beam measures the positional relationship between the separated components. This extraction eliminates the transmission of harmful factors while maintaining measurement capability.
Solution Approach 2:
An overhead beam serves as an intermediary measurement tool that spans between the sensor stage and the projection optical system. This beam acts as a reference that is not affected by local vibrations or heat, providing a stable basis for measuring positional relationships without being influenced by the harmful factors affecting the individual components.
3Device complexity
If the liquid supply device is integrally supported together with the projection optical system, then the structure is simplified, but vibration generated in the liquid supply device is transmitted to the projection optical system and exposure precision is deteriorated
Solution Approach 1:
The liquid supply device is extracted from the projection optical system and mounted on a separate movable stage. This separation prevents vibration from the liquid supply operations from being transmitted to the projection optical system, protecting exposure precision. The liquid supply function is maintained independently while eliminating its harmful vibrational effects on the optical system.
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 solution effectively reduces vibration influence on the projection optical system, improving exposure precision and simplifying assembly and maintenance by using a lightweight, inexpensive mechanism that thermally separates the measuring and projection optical systems, thereby maintaining high image forming ability.
Implementation Method 1
a first support device (38A, 38B, 38C, 39A) which has a first soft structure (38A) and which supports the measuring unit (15) in a hanging manner separately from the projection optical system (PL)
Data Source
AI summary
Disclosed is an exposing apparatus which projects an image of a pattern by a projection optical system, comprising a measuring unit having a sensor which measures a positional relationship between the projection optical system and a member which is positioned in relation to the projection optical system, and a first support device which has a first soft structure and which supports the measuring unit in a hanging manner separately from the projection optical system.