Impedance Matching Network for 13.56 MHz Plasma RF System Based on the Combination of GaN-HEMTs and Relays

In MHz plasma RF power systems, real-time impedance matching is essential to handle load impedance variations, minimize reflection power, and maximize output power. This paper presents a novel <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Gamma$</tex>-type impedance matching network for 13.56 MHz RF plasma system, comprises array of capacitors switched by GaN-HEMTs as well as relays (G-R IMN), Compared with existing VVC and MOSFET switching capacitor approaches, fast response can be achieved since stepper motor is left out, while the deviation caused by parasitic capacitance of MOSFET also avoided. A <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$13.56 \text{MHz} / 1 ~\text{kW}$</tex> simulation model of the RF plasma system incorporating a MHz-frequency detection circuit validates its performance, Impedance matching of the plasma load can be completed within two operations, demonstrating a matching time within 0.15 ms and an 8 % improvement in accuracy under varying load conditions.