Parallel RF Bus and Return Conductor for Plasma Chamber Electrode
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Solution Overview
Problem
Conventional RF power connection designs in plasma chambers result in high peak voltages due to complex impedance, leading to atmospheric arcing and capacitor failure in RF circuitry.
Innovation Solution
The implementation of parallel RF bus and RF return bus conductors reduces inductance and peak voltages by connecting the RF bus conductor to the plasma chamber electrode with an RF return bus conductor grounded, and orienting the RF bus conductor perpendicular to the electrode surface to minimize parasitic capacitive coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional RF power connection design is used, then RF power can be coupled to the plasma chamber electrode, but high peak voltages occur due to complex impedance with significant inductive component
Solution Approach 1:
The patent changes the physical configuration parameters of the RF connection system by introducing parallel RF bus and RF return bus conductors with specific geometric arrangement. This changes the electrical parameters (inductance, impedance) of the connection, transforming the system from high-inductance to low-inductance configuration, thereby reducing peak voltages while maintaining RF power coupling capability
Solution Approach 2:
The patent transitions from a conventional single-point or series RF connection to a parallel multi-dimensional bus structure. The RF bus conductor connects to the electrode at multiple points along its length rather than at a single point, creating a distributed connection geometry that reduces current density and inductive effects, thereby improving reliability
2Power
If conventional RF power connection design is used, then RF power can be supplied to the electrode, but atmospheric arcing occurs in the RF circuitry
Solution Approach 1:
By changing the geometric parameters of the RF connection (parallel bus conductors with optimized spacing and orientation perpendicular to the electrode), the patent reduces the inductive component of the impedance. This parameter change lowers peak voltages to levels that prevent atmospheric arcing while maintaining effective RF power supply to the electrode
3Power
If conventional RF power connection design is used, then RF power can be coupled to the plasma, but capacitor failure occurs in the RF circuitry
Solution Approach 1:
The patent applies parameter changes to the RF connection geometry (parallel bus conductors oriented perpendicular to the electrode surface), which reduces the inductive impedance and consequently the peak voltage stress on capacitors. This extends capacitor life and improves reliability while maintaining RF power coupling functionality
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 configuration reduces the risk of atmospheric arcing and capacitor failure, enhancing the reliability of RF circuitry by lowering peak voltages and inductance in the RF connection.
Implementation Method 1
The parallel RF bus and RF return bus conductors reduce the inductance of the electrical connection between the RF input and the plasma chamber electrode
Implementation Method 2
orienting the RF bus conductor perpendicular to the electrode surface to minimize parasitic capacitive coupling
Data Source
AI summary
For coupling RF power from an RF input of a plasma chamber to the interior of a plasma chamber, an RF bus conductor is connected between the RF input and a plasma chamber electrode. In one embodiment, an RF return bus conductor is connected to an electrically grounded wall of the chamber, and the RF bus conductor and the RF return bus conductor have respective surfaces that are parallel and face each other. In another embodiment, the RF bus conductor has a transverse cross section having a longest dimension oriented perpendicular to the surface of the plasma chamber electrode that is closest to the RF bus conductor.