In low-temperature inductively coupled radio frequency (rf) plasmas, electrons and ions that gain energy from the electric field can transfer a portion of energy to neutral particles. The resulting radial variation of the neutral gas temperature [Formula: see text] can significantly influence the radial distributions of reaction rates and radical densities on the substrate, thus affecting the etching/film deposition uniformity. In this work, we perform an experimental study on the dependence of the neutral gas temperature [Formula: see text] on external parameters (i.e., rf power, pressure, and gas component) in inductively coupled Ar and Ar/O2 plasmas by using a fiber Bragg grating sensor. To analyze the correlation between [Formula: see text] and the plasma characteristics, a Langmuir probe is used to measure the electron density [Formula: see text], effective electron temperature [Formula: see text], and ion density [Formula: see text] under the same discharge conditions. It is found that in both Ar and Ar/O2 plasmas, neutral gas heating is sensitive to plasma density. As the plasma density increases with the pressure/power, the collisions of ions and electrons with neutral particles are enhanced so that [Formula: see text] increases monotonically. With the increase of O2 content, [Formula: see text] and [Formula: see text] are observed to decrease due to enhanced dissociation and excitation of O2, leading to a decrease in [Formula: see text]. The radial profile of [Formula: see text] exhibits a parabolic distribution in pure Ar discharges, whereas it evolves through a center-flat shape into a saddle shape with the increase of O2 content. The variation of [Formula: see text] with rf power during the E-to-H mode transition is also presented and discussed.

In this work, a fluid/Monte Carlo Collision (fluid/MCC) hybrid model is newly developed based on the framework of Multi-Physics Analysis of Plasma Sources (MAPS). This hybrid model could enjoy great accuracy in predicting the nonequilibrium phenomena in capacitively coupled plasmas (CCPs) and meanwhile avoid the limitation caused by the computational cost. Benchmarking against the well-established particle-in-cell/Monte Carlo collision (PIC/MCC) method and comparison with experimental data have been presented both in electropositive N2 discharges and electronegative O2 discharges. The results indicate that in N2 discharges, the ion density evolves from a uniform distribution to an edge-high profile as power increases. Besides, the electron energy distribution function (EEDF) at the bulk center exhibits a “hole” at about 3 eV, and the “hole” becomes less obvious at the radial edge, because more low energy electrons are generated there. In O2 discharges, the EEDF exhibits a Druyvesteyn-like distribution in the bulk region, and it evolves to a Maxwellian distribution in the sheath, indicating the dominant influence of the electric field heating there. The results obtained by the hybrid model agree well with those calculated by the PIC/MCC method, as well as those measured by double probe, except for slight discrepancy in absolute values. The qualitative agreement achieved in this work validates the potential of this hybrid model as an effective tool in the deep understanding of the plasma properties, as well as in the improvement of the plasma processing.