Rotating RF Applicator Coil for Arcing Reduction
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Solution Overview
Problem
Rotatable substrate supports used in semiconductor manufacturing for RF power application face issues with arcing due to high-voltage/current electrical connections, leading to damage in processing chambers.
Innovation Solution
A substrate support assembly with a shaft assembly, pedestal, and rotary connectors, where the rotary connectors include a rotating RF applicator with a first and second coil member configuration that provides RF power through a conductive housing, minimizing arcing by efficient electromagnetic coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional electrical connection methods (rolling RF-rings, RF-brushes, RF pantographs) are used for rotating substrate supports, then RF power can be transmitted to the rotating pedestal, but arcing occurs due to high-voltage/current which damages the chamber
Solution Approach 1:
The patent replaces traditional mechanical electrical connection methods (slip rings, brushes, pantographs) with an electromagnetic coupling system. A rotating coil on the rotating pedestal electromagnetically couples with a stationary coil on the chamber wall through a dielectric barrier, transmitting RF power without direct electrical contact. This eliminates arcing and mechanical wear while maintaining RF power transmission capability.
Solution Approach 2:
The patent introduces a dielectric barrier (such as a ceramic plate or insulating material) as an intermediary between the rotating and stationary coils. This dielectric medium allows electromagnetic energy to pass through while preventing direct electrical contact and arcing. The dielectric barrier acts as a mediator that enables safe RF power transmission across the rotating interface.
2Reliability
If direct electrical connections are made for RF power application, then RF power can be delivered to the substrate support, but high-voltage arcing occurs that damages processing chambers
Solution Approach 1:
The patent replaces direct mechanical electrical connections with an electromagnetic induction system. The rotating coil and stationary coil are positioned to provide magnetic coupling, allowing RF power to be transferred inductively without direct electrical contact. This substitution eliminates the arcing problem inherent in direct electrical connections while maintaining reliable RF power delivery.
Solution Approach 2:
The patent converts the potentially harmful high-voltage arcing into a beneficial electromagnetic coupling mechanism. By using electromagnetic induction through a dielectric barrier, the system achieves safe and efficient RF power transmission. The high voltage that would cause arcing in direct connections is instead utilized to create a strong electromagnetic field for wireless power transfer across the rotating interface.
3Adaptability or versatility
If conventional rotary connectors are used for RF application, then rotation is enabled, but arcing reduces operational reliability and increases maintenance needs
Solution Approach 1:
The patent replaces mechanical rotary connectors with an electromagnetic coupling system that enables rotation without mechanical electrical contacts. The rotating coil mounted on the rotating pedestal can rotate freely while maintaining electromagnetic coupling with the stationary coil. This provides full rotational capability while eliminating the reliability issues and maintenance requirements of conventional rotary connectors.
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 arcing and enhances RF power transmission efficiency, ensuring reliable operation and reducing chamber damage, with potential for up to 80% increase in RF transmittance efficiency.
Implementation Method 1
the rotatable coil member electromagnetically couples with the stationary coil member when the rotatable radio frequency applicator is energized and provides a radio frequency power to the pedestal through the shaft assembly
Data Source
AI summary
A substrate support assembly includes a shaft assembly, a pedestal coupled to a portion of the shaft assembly, and a first rotary connector coupled to the shaft assembly, wherein the first rotary connector comprises a first coil member surrounding a rotatable shaft member that is electrically coupled to the shaft assembly, the first coil member being rotatable with the rotatable shaft, and a second coil member surrounding the first coil member, the second coil member being stationary relative to the first coil member, wherein the first coil member electrically couples with the second coil member when the rotating radio frequency applicator is energized and provides a radio frequency signal/power to the pedestal through the shaft assembly.