Floating Electrode Plasma Source for High-Temperature Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plasma source assemblies in substrate processing chambers face issues with contamination from fluorine-containing materials at high temperatures, leading to thermal stress and cracking of dielectric spacers, resulting in equipment downtime.
Innovation Solution
Employing conductive metal or metal alloy springs, such as those comprising cobalt, chromium, nickel, and molybdenum, to replace o-rings and prevent thermal stress on dielectric spacers, while maintaining electrical communication and preventing cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluorine-containing materials (o-rings) are used in plasma source assemblies, then sealing is achieved, but thermal stress and cracking occur at high temperatures leading to equipment downtime
Solution Approach 1:
The patent replaces permanent sealing components (o-rings) with sacrificial fluorocarbon deposits that can be easily removed and reapplied. The fluorocarbon layer serves as a temporary sealing mechanism that can be refreshed without replacing entire sealing components, eliminating thermal stress accumulation and cracking issues associated with reusable o-rings at high temperatures
Solution Approach 2:
The patent changes the sealing mechanism from mechanical (o-rings under compression) to chemical (fluorocarbon deposition). By depositing fluorocarbon layers through plasma processes and controlling their thickness and composition, the sealing parameter is optimized for high-temperature operation without the thermal expansion and degradation issues that cause cracking in traditional elastomeric seals
2Stability of the object's composition
If electrodes are held fixed relative to dielectric spacers, then structural stability is maintained, but thermal expansion causes stress and potential failure
Solution Approach 1:
The patent introduces floating electrodes that can dynamically adjust their position relative to dielectric spacers in response to thermal expansion. The electrodes are not rigidly fixed but are allowed to float on the fluorocarbon sealing layer, enabling them to move as temperature changes occur, thereby eliminating thermal stress while maintaining stable electrical discharge geometry through self-adjustment
3Device complexity
If traditional sealing materials are used, then assembly simplicity is maintained, but fluorine contamination occurs in the chamber
Solution Approach 1:
The patent extracts the harmful fluorine-containing sealing materials (o-rings) from the high-temperature plasma environment and replaces them with fluorocarbon deposits applied only where needed for sealing. This extraction eliminates the source of fluorine contamination while maintaining the necessary sealing function, as the fluorocarbon is deposited as a thin controlled layer rather than using bulk fluorine-containing elastomers that decompose and contaminate the chamber
Solution Approach 2:
The patent introduces fluorocarbon deposits as an intermediary sealing layer between the electrodes and chamber components. This intermediary layer provides the necessary sealing function without requiring direct contact between traditional fluorine-containing seals and the plasma environment, thereby preventing fluorine contamination while maintaining assembly simplicity through a straightforward deposition process
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 use of metal alloy springs effectively prevents fluorine contamination and cracking, ensuring continuous operation of plasma source assemblies at high temperatures without degrading performance.
Implementation Method 1
a first spring disposed between the bottom surface of the first electrode and the dielectric spacer; and a second spring disposed between the top surface of the second electrode and the dielectric spacer
Implementation Method 2
plasma source assemblies comprising a first electrode comprising a conductive plate
Data Source
AI summary
A plasma source assembly for use with a substrate processing chamber is described. The assembly includes a spring which is disposed between electrodes and a dielectric ring.