Electrostatic Chuck Refurbishment for Leakage Rate Reduction
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Solution Overview
Problem
Electrostatic chucks used in substrate processing suffer from surface feature erosion, leading to increased leakage rates and eventual discard, as existing technologies lack effective refurbishment methods to extend their lifespan.
Innovation Solution
A method for refurbishing electrostatic chucks by polishing surface features without removing them initially, and if necessary, performing a second polishing procedure to remove features and form new ones, optimizing the surface for multiple refurbishments and extending the chuck's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrostatic chuck is used for substrate processing, then substrate temperature regulation is achieved, but surface features erode over time increasing leakage rate
Solution Approach 1:
The patent applies the discarding and recovering principle by establishing a refurbishment process that recovers the electrostatic chuck's functionality through systematic restoration. When leakage rate exceeds thresholds, the chuck undergoes refurbishment including cleaning, inspection, and surface feature restoration, allowing it to be recovered and reused rather than discarded, thus extending operational lifespan while maintaining reliability standards
Solution Approach 2:
The patent applies parameter changes by establishing specific leakage rate thresholds (e.g., 100 SCCM, 50 SCCM, 10 SCCM) that trigger different refurbishment actions. By monitoring and changing the operational parameters (leakage rate measurements) and corresponding responses (refurbishment intensity), the system optimizes both reliability maintenance and lifespan extension
2Ease of manufacture
If traditional polishing procedures are used, then surface features are removed, but multiple refurbishments are not possible
Solution Approach 1:
The patent applies preliminary action by performing careful assessment and selective polishing procedures that preserve surface features for future refurbishments. Instead of completely removing surface features, the process preliminarily addresses leakage issues through targeted cleaning and minor restoration, leaving the chuck prepared for multiple future refurbishment cycles rather than single-use disposal
Solution Approach 2:
The patent establishes a hierarchical refurbishment approach where surface features are recovered and preserved through controlled polishing rather than complete removal. The process recovers the chuck's functionality by addressing only the necessary areas, maintaining surface features for future reuse and enabling multiple refurbishment cycles
3Reliability
If electrostatic chuck is discarded at typical leakage rates, then processing reliability is maintained, but cost increases due to frequent replacement
Solution Approach 1:
The patent directly applies discarding and recovering by intercepting the chuck before complete failure, refurbishing it at controlled intervals based on leakage rate monitoring, and recovering its full functionality. This prevents premature disposal and enables multiple recovery cycles, reducing material loss and replacement costs while maintaining processing reliability
Solution Approach 2:
The patent implements feedback through systematic leakage rate monitoring and assessment procedures. By continuously measuring leakage rates and providing feedback on chuck condition, the system determines optimal refurbishment timing, preventing both premature disposal and operation beyond reliable thresholds, thus optimizing both reliability and resource utilization
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 approach significantly extends the lifespan of electrostatic chucks from 100-200 RFHrs to up to 4000 RFHrs, providing 5-20 times the life span of traditional chucks and offering substantial cost savings through repeated refurbishment.
Implementation Method 1
A refurbisher polishes an electrostatic chuck using a first polishing procedure that polishes surface features on a surface of the electrostatic chuck
Implementation Method 2
During processing, a heat conductive fluid such as helium gas is pumped into an interface between the electrostatic chuck and the supported substrate
Implementation Method 3
Electrostatic chucks are used to support substrates during processing
Data Source
AI summary
An electrostatic chuck includes a metal base plate, an electrostatic puck bonded to the metal base plate, and surface features on the surface of the electrostatic puck. The electrostatic puck includes an electrode embedded in the electrostatic puck. A surface of the electrostatic puck has a flatness of below 10 microns. The surface features include mesas and a sealing band around a perimeter of the electrostatic puck. The surface features have an average surface roughness of approximately 2-6 micro-inches. The corners of the surface features are not rounded.