Processing Chamber Lid Alignment Using a Centering Ring
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Solution Overview
Problem
In atomic layer deposition and chemical vapor deposition processing chambers, misalignment between showerheads and wafer pedestals leads to overspray and unwanted deposition on process kits, causing contamination and increased operating costs due to the need for frequent replacement of process kits.
Innovation Solution
A method and apparatus for calibrating and aligning showerheads relative to wafer pedestals using a centering ring and vision system, determining concentricity across multiple support surfaces to achieve precise positioning and reduce overspray, involving the positioning of a centering ring adjacent to the processing chamber lid, determining concentricity, and adjusting its position to an average central position for optimal alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If showerheads and wafer pedestals are not precisely aligned, then material overspray occurs and deposits on process kits, but increasing alignment precision requires complex calibration procedures and additional components
Solution Approach 1:
A centering ring is introduced as an intermediary component between the chamber lid and the calibration system. The centering ring provides a reference structure that simplifies the alignment process by establishing a clear geometric reference (concentricity) that can be easily measured and adjusted, reducing the overall system complexity while improving alignment precision
Solution Approach 2:
The patent replaces complex mechanical alignment mechanisms with a vision system that uses optical methods to measure concentricity. The vision system captures images of the centering ring and substrate support to determine alignment, substituting mechanical measurement and adjustment mechanisms with optical detection and computational analysis
2Measurement precision
If alignment calibration is performed using multiple support surfaces, then alignment accuracy improves, but measurement time and processing complexity increase
Solution Approach 1:
The centering ring is pre-positioned on the chamber lid before the substrate support is installed. This preliminary positioning establishes a fixed reference structure that remains stationary during subsequent measurements, allowing multiple support surfaces to be measured without repositioning the reference, thereby reducing total calibration time while maintaining high measurement precision
Solution Approach 2:
The patent combines multiple concentricity measurements from different support surfaces into a single comprehensive alignment assessment. The vision system integrates data from measurements of multiple support surfaces to determine overall alignment accuracy, reducing the need for separate calibration procedures for each surface and decreasing total calibration time
Data Source
AI summary
Methods for aligning a processing chamber using a centering ring and processing chambers having the centering ring are describes. The method includes determining an average central position for the centering ring based on the concentricity of the centering with the support surfaces and adjusting average position of centering ring to a final position based on the average central position.