Quantum chemical calculations were employed to get insight into the mechanisms; involved in plasma-induced nitridation of gate oxide that will suppress boron penetration. The roles played by the nitrogen cations and atoms were explored. It was shown that B interaction with siloxane rings that contain incorporated nitrogen yielded a larger energy gain than rings without nitrogen. This explains the chemical nature of the nitrogen-induced barrier effect. Monte Carlo simulations were used to simulate the necessary energy of incident N-2 cations to produce the bond cleavage down to a particular depth in the amorphous SiO2 layer. A combination of the hybrid plasma equipment model and plasma chemistry Monte Carlo codes was used to simulate nitrogen atomic and cation fluxes and their angular and energy distributions at the water surface. Combining simulated cation energies with PROMIS Monte Carlo simulation results makes it possible to derive plasma process parameters that will permit a desired level of nitridation to be reached.