Inductively coupled discharge also uses an RF power supply like capacitively coupled discharge. The frequency of the power is usually in the tens of kHz to tens of MHz range. For a commonly used cylindrical plasma chamber shown below, an antenna is usually wrapped around the electrically insulating chamber wall. RF generator drives high alternating current through coil antenna, which creates an alternating magnetic field within the plasma chamber. According to Maxwell equations, the oscillating magnetic field will generate an oscillating electric field in the plasma chamber. Eventually, the electric field will accelerate the electrons and generate plasma. Since the excitation force is delivered through a magnetic field, inductively coupled discharge is also called “H-discharge”. For some applications, it is described as “electrodeless discharge” because there is no cathode or anode required for inductively coupled discharge.
