Symmetrical Plural-Coil Plasma Source RF Distribution
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Solution Overview
Problem
As substrate size increases and device geometry shrinks, achieving uniform etch or deposition rates across the entire surface of substrates in plasma processing becomes challenging due to chamber design asymmetries, temperature distribution non-uniformities, and gas distribution control issues in inductively coupled plasma sources.
Innovation Solution
A plasma reactor design featuring first and second coil antennas with RF feed terminals, a conductive feed plate, axial rods, and radial conductive feed rods, along with shielding and impedance matching networks, to optimize RF power distribution and plasma ion density control across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If inductively coupled plasma sources are used for processing, then plasma generation is achieved, but process uniformity deteriorates due to chamber design asymmetries, temperature distribution non-uniformities and gas distribution control issues
Solution Approach 1:
The patent applies asymmetry by intentionally introducing asymmetrical features into the chamber design, specifically an asymmetrical RF electrode arrangement and asymmetrical gas distribution system. These controlled asymmetries are designed to compensate for the natural symmetrical asymmetries in the chamber, thereby improving overall process uniformity across the substrate surface
Solution Approach 2:
The patent implements local quality by creating region-specific conditions within the chamber. Different zones of the chamber receive tailored RF power distribution and gas flow rates to account for local variations in temperature, plasma density, and process requirements, ensuring uniform processing across the entire substrate area
2Area of stationary object
If substrate size increases, then processing capacity is improved, but achieving uniform etch or deposition rates across the entire surface becomes more difficult
Solution Approach 1:
The patent applies segmentation by dividing the RF power delivery system into multiple independent zones with separate RF electrodes. Each zone can be independently controlled to optimize plasma density and process parameters for that specific region, enabling uniform processing across large substrate areas by addressing local variations in power distribution and gas flow
Solution Approach 2:
The patent implements dynamics by enabling real-time, independent adjustment of RF power levels and gas flow rates to different chamber zones. This dynamic control allows the system to adapt to changing process conditions and substrate positions, maintaining uniformity even as substrate size increases
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 design enhances plasma distribution symmetry, allows independent control of plasma density, and maintains process uniformity even with larger substrates, minimizing asymmetrical non-uniformities and skew effects.
Implementation Method 1
plasma is generated by inductive coupling of RF power to process gases inside the chamber
Data Source
AI summary
A plasma reactor has an overhead inductively coupled plasma source with two coil antennas and symmetric and radial RF feeds and cylindrical RF shielding around the symmetric and radial RF feeds. The radial RF feeds are symmetrically fed to the plasma source.