Patent attributes
In one embodiment, a method of impedance matching and controlling the power delivered to a plasma chamber is disclosed. A matching network includes a variable reactance element (VRE), the VRE having different positions for providing different reactances. Based on a determined parameter, the method determines potential new positions for the VRE that would have a threshold effectiveness in providing an impedance match between the RF source and the plasma chamber. A preferred position for the VRE is determined by determining the one of the potential new positions meeting the threshold effectiveness whose efficiency in delivering RF power from the RF input to the RF output would cause an RF power at the RF output to be closest to a desired RF power.