Simulations of stochastic heating induced by RF biased sheath in inductively coupled plasmas

In this study, a 2D(two-dimensional) fluid/EMC(electron Mento Carlo) hybrid model is established to investigate the stochastic heating in an argon ICP(inductive coupled plasma) with an RF capacitive bias power applied on the subplate. The RF coil current of 13.56 MHz is adjusted to keep the inductive power at 60 W. The pressure is fixed at 3 mTorr, so the capacitive ohmic heating is negligible. The bias voltage is turned between 50-500 V, and the frequency of the bias power is set to be 13.56 MHz, 27.12 MHz and 40.68 MHz, respectively. In the simulation, the dc self-bias is adjusted by balancing the electron flux and ion flux at the subplate during one RF cycle. Electron velocity distribution function in vertical direction(EVDF) is collected, and the stochastic heating power is calculated by the classical hard wall model. The results show that the peak of the areal stochastic heating appears when the sheath starts to expand, and the power raises faster with the increase of the bias frequency. Besides, the inaccuracy caused by the inconsistent of the electrostatic field with the macroparticle distribution in EMC is analyzed.