Harmonic Filtering Circuit for Plasma Chamber Voltage Sources

The patent converts the harmful harmonic frequency components into a beneficial filtering action. By designing the filtering circuit with specific LC components, the harmful harmonics are identified and removed, while the fundamental frequency is preserved and even enhanced for driving the plasma chamber. This transforms the potential damage into a protective mechanism.

The filtering circuit acts as an intermediary between the voltage source and the plasma chamber. It receives the full-power signal from the voltage source, selectively removes harmful harmonic components, and delivers a cleaned signal to the plasma chamber. This intermediary structure protects the voltage source while maintaining process effectiveness.

The filtering circuit is segmented into distinct functional blocks: a rejection block for removing specific harmonic frequencies and a pass block for allowing the fundamental frequency to pass. This segmentation makes the complex filtering task manageable and modular, simplifying both design and maintenance while achieving reliable harmonic removal.

The patent utilizes parameter changes in LC circuit components (inductors and capacitors) to achieve frequency-selective filtering. By adjusting the inductance and capacitance values, the circuit is tuned to specifically target harmonic frequencies while passing the fundamental frequency. This parameter-based approach provides a compact and efficient filtering solution without excessive complexity.