Electrostatic Chuck Gas Hole Layout for Discharge Suppression
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Solution Overview
Problem
Existing electrostatic chucks experience frequent discharges along linear gas holes due to exposed metal surfaces, which can compromise the integrity of the electrostatic attraction and processing environment.
Innovation Solution
The electrostatic chuck design incorporates non-overlapping first and second gas holes with communication grooves or paths on the dielectric substrate and base plate, ensuring a longer creepage distance and reduced exposure of metal surfaces, and includes an insulating film and adhesive layer to prevent discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If linear gas holes are formed to penetrate the joint portion of the dielectric substrate and base plate, then gas supply function is improved, but discharge occurs readily along the linear gas holes due to exposed metal surfaces
Solution Approach 1:
The linear gas hole is divided into multiple separate gas holes that are offset from each other. The first gas hole in the dielectric substrate and the second gas hole in the base plate are positioned at different locations, breaking the continuous linear path that previously allowed discharge to occur readily along the metal-exposed surface.
Solution Approach 2:
The design transitions from a one-dimensional linear penetration path to a two-dimensional offset arrangement. By positioning gas holes at different lateral positions in the dielectric substrate versus the base plate, the patent creates a stepped or错位 (offset) configuration that increases the creepage distance and prevents direct discharge paths.
2Force
If metal base plate is used as attracting electrode, then electrostatic attraction function is achieved, but exposed metal on inner surface of gas holes creates discharge paths
Solution Approach 1:
The patent introduces an insulating coating as an intermediary layer on the inner surfaces of the gas holes in the base plate. This coating acts as a mediator that maintains the electrostatic attraction function of the metal base plate while preventing direct discharge paths by covering the exposed metal surfaces that would otherwise create harmful discharge routes.
Solution Approach 2:
A thin insulating film or coating is applied to the inner surfaces of the gas holes. This thin film structure provides electrical insulation to prevent discharge while maintaining the structural integrity and gas flow functionality of the gas hole passages.
3Temperature
If gas holes are formed in dielectric substrate and base plate, then temperature regulation is enabled, but direct alignment of openings creates short discharge paths
Solution Approach 1:
The patent employs asymmetric positioning of gas holes between the dielectric substrate and the base plate. Instead of aligning the gas holes directly opposite each other (symmetric arrangement), the first gas hole and second gas hole are positioned at offset locations, creating an asymmetric configuration that elongates the discharge path and suppresses discharge while maintaining temperature regulation functionality.
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 suppresses discharges, maintaining stable electrostatic attraction and enhancing the reliability of the electrostatic chuck by minimizing direct metal exposure and optimizing gas flow paths.
Implementation Method 1
a joining layer which is provided between the dielectric substrate and the base plate and which is formed of an insulating material
Implementation Method 2
When voltage is applied to the attracting electrode, an electrostatic force is created and a substrate placed on the dielectric substrate is attracted and held
Data Source
AI summary
An electrostatic chuck includes: a dielectric substrate on which at least one first gas hole is formed; a base plate on which at least one second gas hole is formed; and a joining layer which is provided between the dielectric substrate and the base plate and which is formed of an insulating material. A first opening being an end of the at least one first gas hole is formed on a surface of the dielectric substrate. A second opening being an end of the at least one second gas hole is formed at a position which differs from the at least one first opening on a surface of the base plate. A communication groove is formed on the surface of the base plate.