Stage Transfer Control Using Current Feedback to Limit Chuck Abrasion

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Solution Overview

Problem

In semiconductor and display device manufacturing, stage apparatuses face challenges in delivering substrates from substrate chucks to pins due to residual attraction forces, which can cause substrate chuck abrasion and affect separation efficiency.

Innovation Solution

A stage apparatus with a control system that adjusts the driving operation of the fine movement stage based on residual attraction force conditions, using a combination of speed, acceleration, and position control to minimize substrate displacement and prevent abrasion, by monitoring drive current values and adjusting movement intervals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the driven member is moved at a high speed to separate the substrate and substrate chuck, then productivity is improved, but horizontal displacement of the substrate occurs due to residual attraction force causing abrasion of the substrate chuck

Engineering Contradiction:
Improvesubstrate delivery speedVSAvoidsubstrate chuck abrasion
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the driving speed variable rather than constant. The control unit adjusts the driving speed of the driven member based on real-time drive current values, creating a dynamic speed profile that adapts to the residual attraction force conditions during substrate separation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the speed parameter dynamically during the separation process. By monitoring drive current values and adjusting the driving speed accordingly, the system optimizes the separation process to minimize substrate displacement and chuck abrasion while maintaining high productivity.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the driven member is moved at a low speed to reduce substrate displacement, then substrate chuck abrasion is reduced, but productivity decreases

Engineering Contradiction:
Improvesubstrate chuck abrasionVSAvoidsubstrate delivery speed
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements periodic action through a multi-stage separation process. The separation occurs in distinct phases: an initial low-speed phase to minimize abrasion, followed by a high-speed phase to maintain productivity. This periodic variation in speed allows the system to achieve both low abrasion and high overall delivery speed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts speed based on real-time conditions. By monitoring drive current values and transitioning between speed levels, the system optimizes the balance between reducing abrasion and maintaining productivity throughout the separation process.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If a fixed driving operation is used for substrate separation, then device complexity is reduced, but the system cannot accommodate varying substrate and chuck characteristics

Engineering Contradiction:
Improveaccommodation of substrate characteristicsVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements feedback control by monitoring drive current values during the separation process and using this information to adjust the driving speed. This feedback mechanism allows the system to adapt to varying substrate and chuck characteristics without requiring complex pre-programming or manual configuration.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically modifying the driving operation based on real-time drive current measurements. The control unit independently optimizes the separation process for different substrate-chuck combinations without external intervention, achieving high adaptability with minimal additional complexity.

Inventive Principle:
Principle #25Self-service

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 approach reduces substrate chuck abrasion and enhances separation efficiency, allowing for high productivity in substrate delivery while accommodating varying substrate and chuck characteristics.

Implementation Method 1

a vacuum chuck mechanism for holding the substrate

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP4421857A1Stage apparatus, lithography apparatus, and article manufacturing method
Publication Date: 2024.08.28 CANON KK
  • EP4421857A1 patent drawingFigure 1
  • EP4421857A1 patent drawingFigure 2
  • EP4421857A1 patent drawingFigure 3

AI summary

A stage apparatus includes a substrate chuck configured to attract and hold a substrate, a pin configured to be able to attract and hold the substrate, the pin being configured to be able to protrude from the substrate chuck through a hole in the substrate chuck, a driving portion configured to move one of the substrate chuck and the pin relative to the other of the substrate chuck and the pin, and a control portion configured to control the driving portion, wherein in a case where the substrate and the substrate chuck separate from each other, the control portion controls the driving portion based on a first condition related to easiness of separation between the substrate and the substrate chuck.