power is about 13 56 mhz as shown in fig3 b the bi polar electrostatic chuck has an inner electrode 28 and an outer electrode 30 the inner electrode 28 and the outer electrode 30 both connects to the dc power 24 and the ac bias power 22 the capacitive impedance 321 for isolation of the inner electrode 28 and the capacitive impedance 322 for isolation of the outer electrode 30 are used to prevent direct currents from entering the ac bias power 22 because capacitors to direct currents are open circuit capactive impedance zc 1 j u03c9c the frequency of direct current u03c9 0 zc u221e the inductive impedance 341 for isolation of the inner electrode 28 and the inductive impedance 342 for isolation of the outer electrode 30 are used to prevent alternating currents from entering the dc power 24 the capacitive impedance 321 for isolation of the inner electrode 28 and the capacitive impedance 322 for isolation of the outer electrode 30 have different impedance values because of different transmitting lines the different impedance values will lead to the power outputs difference between the inner electrode 28 and the outer electrode 30 the power of ac bias power 22 p generator minus the power of the consumption of the impedance p impedance equals to power.