Changes of discharge state in inductively coupled plasma (ICP) were investigated by use of a radio frequency (RF) impedance analyzer. A voltage loaded on the ICP coil and a current flowing within the coil were plotted against the RF power, and the two curves exhibited similar patterns. The discharge states, i.e., the E mode, the H mode, and an appearance of the skin effect were inferred from the
... [Show full abstract] curves and a theoretical interpretation by use of a circuit model. The inference was also supported by curves of a real part of load impedance and of a load impedance phase angle versus the power.
