Inductively coupled plasma (ICP) has been widely used in semiconductor industry, due to its perfect characteristics of reduced ion damage, independently controllable ion energy and high density plasmas.1, 2 In the actual industrial processes such as etching process, to control ion energy and plasma density, two independent RF power sources are conventionally applied to ICP, i.e., the power source through the coil and the bias source applied to a substrate electrode. And, the RF bias discharge is the same as capacitively coupled plasma (CCP).