Automatic tuning in a tapped RF transformer inductive source of a plasma reactor for processing a semiconductor wafer

摘要

In a plasma reactor for processing a semiconductor wafer having an overhead inductive coil antenna, automatic compensation for the load impedance shift that accompanies plasma ignition is achieved using fixed elements. This is accomplished by applying RF power to an intermediate tap of the coil antenna that divides the antenna into two portions, while permanently suppressing the inductance of one of the two portions to an at least nearly fixed level.