Diagnostic of Capacitively Coupled Low Pressure Radio Frequency Plasma: An Approach through Electrical Discharge Characteristic

Abstract

Abstract-Low temperature radio frequency plasma is widely used in low temperature plasma processing medium for material processing in many fields including microelectronics, aerospace, and the biology. For proper utilization of the process, it is very much important to know the plasma parameters. In this paper a technique is reported to determine the plasma parameters from the electrical discharge characteristic of a capacitivly couple radio frequency argon plasma. The homogeneous discharge model is modified to make it applicable in low pressure by incorporating the plasma series resonance effect. The effect on the plasma resistance by the change in drift velocity of the electron with rf electric filed is also considered. The electron density and temperature is found to be well agreed with the Langmuir probe diagnostic result, which is in the range of 0.5x10 10 to 4.5x10 10 cm -3 and 1.4 to 1.6 ev for wide range of rf power.Index Terms-Capacitive couple radio frequency plasma, discharge characteristic, homogeneous discharge model, plasma parameters, power balance.