Is collisionless heating in capacitively coupled plasmas really collisionless?

International audienceBy performing a combination of test-particle and particle-in-cell simulations, we investigate electron heating in single frequency capacitively coupled plasmas (CCPs). In agreement with previous theoretical considerations highlighted in Kaganovich et al (1996 Appl. Phys. Lett. 69 3818), we show that the level of true collisionless/stochastic heating in typical CCPs is significantly smaller than that due to collisional interactions; even at very low pressures and wide gap lengths. Fundamentally electron heating is a collisional phenomenon whereby particle collisions provide the vital phase randomization and stochastization mechanism needed to generate both a local (or ohmic) heating component, and a non-local (or hybrid) heating component