A planar one-dimensional particle-in-cell simulation with Monte Carlo Collisions (PIC/MCC) has been used to study a 13.56 MHz weakly dissociated oxygen discharge. In this case molecular oxygen is the dominant neutral species and O2+ the dominant positive ion species. Ion and electron density profiles have been obtained at pressures of 50 mTorr and 1 Torr. It was showed that as pressure increases the density profiles become flatter compared to the low-pressure case, where the profiles have a large sheath. The electron energy distribution functions (eedf) are non-Maxwellians, which is typical for electronegative gases. In order to explain this effect electron heating rates have been obtained for low and high pressure cases.
