Focus Ring Organic Film for Plasma Ion Incidence
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Solution Overview
Problem
In plasma processing, the focus ring's position discrepancy affects the incidence direction of ions on the substrate, leading to uneven etching patterns due to changes in its thickness during processing, which is not effectively addressed by existing methods.
Innovation Solution
A plasma processing method that forms an organic film on the focus ring to maintain its position relative to a reference point, ensuring vertical ion incidence by alternately or simultaneously supplying gases to form the film, thereby correcting the focus ring's position and maintaining uniform ion incidence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the focus ring is used to adjust the plasma-sheath interface shape for vertical ion incidence, then ion incidence uniformity is improved, but the focus ring thickness decreases during processing causing position discrepancy and oblique ion incidence
Solution Approach 1:
The patent applies preliminary action by forming an organic film on the focus ring before plasma processing begins. This pre-formed film compensates for the thickness reduction that occurs during processing, ensuring the focus ring maintains its correct position and the plasma-sheath interface remains properly shaped throughout the etching process, thereby preventing oblique ion incidence
Solution Approach 2:
The patent changes the physical-chemical state of the focus ring surface by coating it with an organic film. This parameter change (adding a film layer) compensates for the thickness reduction during processing, maintaining the focus ring's effective position and its ability to control vertical ion incidence on the substrate
2Productivity
If the focus ring thickness decreases during processing, then processing continues, but position discrepancy increases leading to oblique ion incidence and uneven etching
Solution Approach 1:
The patent applies beforehand cushioning by pre-forming an organic film on the focus ring that acts as a buffer against thickness reduction during processing. This film cushioning prevents the focus ring position from deviating, thereby maintaining etching pattern uniformity throughout the entire processing cycle without requiring frequent interruptions for ring replacement
3Device complexity
If no organic film is formed on the focus ring, then the process is simpler, but the focus ring position becomes unstable during processing
Solution Approach 1:
The patent applies self-service by having the focus ring receive an organic film coating that automatically compensates for its own thickness reduction during processing. This self-service mechanism maintains position stability without requiring external adjustment mechanisms or complex control systems, balancing simplicity with reliability
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 method ensures consistent vertical ion incidence on the substrate, reducing oblique incidence and maintaining uniformity in etching patterns even as the focus ring thickness decreases, thereby improving processing accuracy and reducing the need for frequent focus ring replacements.
Implementation Method 1
forming an organic film on the focus ring by polymerizing a processing gas in a plasma state
Implementation Method 2
plasma of a processing gas is generated. The substrate is treated with ions supplied from the plasma
Data Source
AI summary
A plasma processing method is performed in a state where a focus ring is disposed on a supporting table to surround an edge of a substrate by a plasma processing apparatus. The plasma processing apparatus includes a chamber and the supporting table provided in the chamber and configured to support the substrate mounted thereon. The plasma processing method includes forming an organic film on the focus ring to reduce a difference between a position of an upper surface of the focus ring in a vertical direction and a reference position, and performing plasma processing on the substrate after the formation of the organic film.