Plasma immersion ion implantation using plasmas generated by radio frequency techniques

Medium density (3 x 109 cm-3) and high density (3 x 1012 cm-3) plasmas, generated by low and medium power rf techniques, have been used for the implantation of 10--20 keV nitrogen ions into mild steel targets which were immersed in the plasma and biased to -20 kV. Use of the high density plasma resulted in significant damage to the surface by arcing. At medium densities the nitrogen was implanted to a depth and dose consistent with expectations, there was no arcing damage, and tests showed improved wear and hardness compatible with the level of implantation