Segmented Shielding Plate for Exposure Apparatus Vibration Control

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Solution Overview

Problem

In exposure apparatuses used for semiconductor manufacturing, wind pressure generated by the movement of the original stage causes vibrations in the projection optical system, leading to inaccurate pattern transfer, and increasing the thickness of shielding plates to reduce vibrations results in increased weight, making them difficult to attach and detach.

Innovation Solution

A lightweight plate supported by multiple support members is placed between the original stage and the projection optical system to reduce wind pressure influence, with the plate's thickness and design allowing easy attachment and detachment, and the support members providing enhanced rigidity and strength to minimize vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the thickness of the shielding plate is increased to increase rigidity and reduce vibration, then the vibration reduction effect is improved, but the weight of the shielding plate increases, making it difficult to attach and detach

Engineering Contradiction:
Improverigidity of shielding plateVSAvoidweight of shielding plate
Core Design Contradiction:
Stability of the object's compositionVSWeight of stationary object

Solution Approach 1:

The shielding plate is divided into multiple separate plates arranged in the vertical direction. Each plate can be independently attached and detached, allowing maintenance operations without removing the entire shielding structure. This segmentation resolves the contradiction by maintaining the overall rigidity of the shielding system while enabling easy attachment and detachment of individual components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shielding structure transitions from a single horizontal plate to multiple plates arranged in the vertical dimension. This dimensional change allows the system to maintain rigidity through vertical stacking while enabling selective attachment and detachment of individual plates, solving the weight-handling problem during maintenance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If the thickness of the shielding plate is increased to reduce excitation of the shielding plate itself, then the vibration transmission to projection optical system is reduced, but the weight increases, affecting ease of attachment and detachment

Engineering Contradiction:
Improvevibration transmission to projection optical systemVSAvoidease of attachment and detachment
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The shielding plate is segmented into multiple thinner plates arranged vertically. Each plate can be easily attached and detached individually, improving ease of operation during maintenance while collectively providing sufficient rigidity to reduce vibration transmission to the projection optical system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shielding structure uses a composite arrangement of multiple plates, potentially with different materials or properties, stacked in the vertical direction. This composite structure achieves the required vibration damping and rigidity while maintaining ease of attachment and detachment of individual components.

Inventive Principle:
Principle #40Composite materials

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 vibrations of the projection optical system due to wind pressure while facilitating easier maintenance by allowing the plate to be easily attached and detached, maintaining the apparatus's operational accuracy and efficiency.

Implementation Method 1

wind pressure generated by movement of a stage

Methodology Applied
Scientific EffectWind pressure: Pressure Increase

Implementation Method 2

the shielding plate itself can vibrate due to the airflow and/or the pressure wave generated by movement of the reticle stage

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP4488755A1Structure, exposure apparatus, and article manufacturing method
Publication Date: 2025.01.08 CANON KK
  • EP4488755A1 patent drawingFigure 1A
  • EP4488755A1 patent drawingFigure 1B
  • EP4488755A1 patent drawingFigure 1C

AI summary

The present invention provides a structure forming a part of an exposure apparatus (100) that includes a stage (150) configured to move on a base (140) while holding an original (M), and a projection optical system (163) configured to project a pattern image of the original onto a substrate (S), the structure comprising: a plate (11) arranged between a moving path of the stage and the projection optical system; and a plurality of support members (12) arranged extending along a lower surface of the plate and configured to support the plate by contacting the lower surface.