METHOD

PURPOSE: A method for applying an RF(Radio Frequency) bias of plasma etching equipment is provided to improve problems of a peak to peak voltage and a self bias voltage of an RF bias by composing a capacitor of a transfer path of an RF bias. CONSTITUTION: A bias is generated from an RF bias source(100). The RF bias is transferred through an impedance matching network(102) connected directly with a chuck for loading a wafer. The RF bias is applied by using only a wafer back capacitor(Cback) as a direct capacitor. The wafer back capacitor(Cback) uses the wafer and the chuck of a plasma chamber as an electrode and an insulating layer coated on the chuck as a dielectric layer. A range of the RF bias is 20 to 200 MHz.