Similarity deviation in capacitively coupled RF O2 plasmas driven by nonlinear collisional processes

Abstract Discharge similarity laws provide an important basis for designing and scaling plasma sources across different spatial and temporal scales, but they are challenged in electronegative gases with complex reaction kinetics. In this work, we use a one-dimensional particle-in-cell/Monte Carlo collision (PIC/MCC) method to systematically study similarity behavior in capacitively coupled radio-frequency (RF) O2 plasmas over 6–50 Pa and 10–30 MHz. We focus on how nonlinear collision processes,