Electrostatic Chuck Stage Mechanism Residual Charge Elimination
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Solution Overview
Problem
Substrates can be deviated or damaged due to residual charges when elevated from an electrostatic chuck, as existing techniques are inadequate in effectively eliminating these charges.
Innovation Solution
A stage mechanism with an electrostatic chuck and a conductive member connected via a connecting member, allowing the conductive member to move between ground potential and a non-ground potential, ensuring the substrate and chuck are in an earth-fault state before lifting, thus eliminating residual charges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If elevating pins are raised while residual charges remain in the electrostatic chuck or substrate, then the substrate can be lifted from the electrostatic chuck, but the substrate may be deviated or damaged due to electrostatic force
Solution Approach 1:
The patent applies preliminary action by discharging residual charges from the electrostatic chuck and substrate before raising the elevating pins to lift the substrate. The charge discharge unit is activated prior to substrate lifting to eliminate accumulated charges, ensuring that no electrostatic force acts on the substrate during the lifting process, thereby preventing substrate deviation or damage.
2Reliability
If conventional charge elimination techniques are used, then residual charges can be reduced, but the substrate deviation or damage cannot be effectively suppressed
Solution Approach 1:
The patent applies local quality by providing separate conductive paths for the electrostatic chuck and substrate through distinct elevating pin structures. The first elevating pins are electrically connected to the electrostatic chuck while the second elevating pins contact the substrate, allowing independent charge discharge control. This localized approach ensures complete charge elimination from both surfaces, effectively preventing substrate deviation during lifting.
3Stability of the object's composition
If the electrostatic chuck maintains electrostatic force for substrate holding, then substrate positioning is stable, but residual charges cause problems during substrate separation
Solution Approach 1:
The patent applies dynamics by making the electrical connection state of the electrostatic chuck and substrate changeable over time. During substrate holding, the electrostatic chuck maintains electrostatic force through electrical connection. During substrate separation, the charge discharge unit is activated to dynamically change the electrical connection state, discharging residual charges before elevating pins raise the substrate, thus eliminating harmful residual charges while maintaining positioning stability during processing.
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 effectively prevents substrate deviation or damage by ensuring residual charges are eliminated before lifting, simplifying the process and maintaining electrostatic force integrity.
Implementation Method 1
a conductive member electrically connected to the conductive film and formed to extend to a rear surface of the electrostatic chuck
Implementation Method 2
an electrostatic force caused by residual charges accumulated in the electrostatic chuck or the substrate
Data Source
AI summary
There is provided a stage mechanism, including: an electrostatic chuck having a conductive film formed on a front surface thereof, the conductive film configured to make electrically contact with a rear surface of a substrate; a conductive member electrically connected to the conductive film and formed to extend to a rear surface of the electrostatic chuck; and a moving member electrically connected to the conductive member via a connecting member and configured to move between a first position connected to a ground potential and a second position not connected to the ground potential.