ESC Pedestal Isolation Structure to Prevent High-Voltage Arcing
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Solution Overview
Problem
Current electrostatic chucks (ESCs) in plasma-based processing systems face issues with voltage isolation, leading to arcing and detrimental effects due to reduced physical separation distances between high-voltage electrodes and ground planes, especially with the addition of extra power and gas lines.
Innovation Solution
The implementation of insulative tubes with dielectric-coated interior surfaces and strategically designed gaps within the tube adapter portion of the ESC, which serves as an interface between the pedestal and the substrate support, effectively isolates RF, AC, and DC signals from the ground plane, preventing arcing by increasing the clearance specification and using materials like polyimide and gold-plated Inconel for high-temperature resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If extra electrodes and gas lines are added to the ESC pedestal, then the functionality and versatility of the processing system is improved, but the physical separation distance between high-voltage components and ground plane is reduced, leading to arcing and detrimental effects
Solution Approach 1:
The patent introduces an insulating coating layer as an intermediary substance between conductive components and the ground plane. This dielectric barrier allows extra electrodes and gas lines to be added to the pedestal while preventing direct electrical contact with the ground, thus maintaining voltage isolation and preventing arcing despite reduced physical separation distances
Solution Approach 2:
The patent replaces reliance on mechanical physical separation with an electrical insulation solution. Instead of maintaining large physical gaps between high-voltage components and ground plane, the invention uses dielectric coatings to provide electrical isolation, allowing compact pedestal design with multiple components while maintaining voltage isolation
2Device complexity
If physical separation distance is reduced to accommodate extra components, then the device complexity is reduced and components are better integrated, but arcing and detrimental effects occur due to insufficient isolation
Solution Approach 1:
The insulating coating acts as a mediator that enables close integration of components without causing arcing. The dielectric layer provides the necessary electrical isolation, allowing electrodes and gas lines to be positioned closer together while preventing harmful electrical discharge to the ground plane
Solution Approach 2:
The patent changes the electrical parameters of the pedestal structure by applying dielectric coatings with specific breakdown voltage characteristics. This allows the physical dimensions to be reduced while maintaining adequate electrical isolation, as the coating material's dielectric strength compensates for the reduced physical separation distance
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 solution enhances voltage isolation, preventing arcing and maintaining the integrity of the seal, even under high-temperature and high-voltage conditions, ensuring reliable operation of the plasma-based processing system.
Implementation Method 1
insulative tubes with dielectric-coated interior surfaces... effectively isolates RF, AC, and DC signals from the ground plane
Implementation Method 2
electrostatic chuck (ESC)... a pedestal supporting the ESC... RF, AC, and DC signals are supplied to the substrate through a lower portion of the pedestal
Data Source
AI summary
Various embodiments include an apparatus to retrofit into an electrostatic chuck (ESC) of an existing plasma-based processing system. The apparatus includes a tube adapter portion having a dielectric coating formed on an inner surface of the tube adapter portion to prevent arcing between high voltage electrodes within the tube adapter portion and a main body of the tube adapter portion during an operation of the plasma-based processing system, a number of insulative tubes with the high voltage electrodes to be enclosed therein, and an enlarged gap portion of the tube adapter portion proximate outboard ones of the plurality of insulative tubes to prevent arcing. Other methods of forming the ESC, and related devices, apparatuses, and systems are disclosed.