Simulation of the distribution of incident ions and depth profile in plasma-based ion implanted layers with different pulse width

The implantation dose and compositional depth profile were studied in the context of cylindrical target with different pulses treated by plasma-based ion implantation. Nitrogen was implanted into silicon wafer clamped on the samples in order to acquire high-quality profile. Auger electron spectroscopy was used to acquire the compositional depth profile at the middle of the Si wafer. The measured results, both implantation dose and depth profile, were compared with the results of theoretical simulation. A method, that combined fluid dynamic model to simulate the sheath expansion and TRIM code to simulate incident ion distribution in the solid was presented. The agreement between the measured results and theoretical calculations for all three cases is good. The implantation dose for the cylinder is increased with increase in pulse width, which is consistent with theoretical prediction. The continuously distributed energy of incident ions and N₂⁺/N⁺ ratio in the plasma shift the depth profile nearer to the surface and reduce the projected range significantly.