Study of plasma characteristics in capacitive discharges operated at very low pressure and in kV range triggered by very high radio-frequency*

In recent years, capacitively coupled discharges (CCP) operated at very high-frequency (VHF) is of great interest. Plasma properties in collisionless CCP discharges operated at very low pressure ( 2 mTorr), applied potential of kiloVolt range triggered by VHF (60 MHz) is reported here. It is observed that a very high density plasma can be produced in collisionless limit which may be of great interest for various industrial applications. It is also noticed the presence of higher harmonics in the centre of discharge which modifies the bulk plasma properties significantly. This is verified by analyzing at the shape of electron energy distribution function (EEDF) in the bulk plasma. The electron heating mechanism in the discharge is also reported here. We have used electrostatic 1D-3V particle-in-cell simulation technique for argon discharges in the present study.