Multi-diagnostic experimental validation of 1d3v PIC/MCC simulations of low pressure capacitive RF plasmas operated in argon *

We systematically compare results of one-dimensional particle-in-cell simulations to experimentally measured plasma parameters. Measurements of the gas temperature, electron density, spatio-temporal electron impact excitation dynamics, and ion flux-energy distribution at the grounded electrode  are performed in a custom built geometrically symmetric reactor in argon gas at pressures ranging from 1 Pa to 100 Pa and at RF (13.56 MHz) voltage amplitudes between 150 V and 350 V. In the experiment, the gas temperature increases significantly beyond room temperature as a function of pressure. The computational results are sensitive to the gas temperature and to the choice of surface coefficients for electron reflection and secondary electron emission, which are both input parameters for the simulation. By adjusting these parameters, we achieve a good quantitative agreement between all measured and computationally obtained plasma parameters. This shows that PIC/MCC simulations can describe experiments correctly over a wide range of operating parameters, if appropriate values for the gas temperature and the surface coefficients are used.