N-2(+) implantation approaches for improving thermal stability of Cu/Mo/Sicontact structure

We have suggested N-2(+) ion modification method to improve the thermal sta bility of Mo thin film by implanting 3 x 10(17) N-2(+) ions/cm(2) with very low acceleration energy of 20 keV. The Mo film modified by N-2(+) ions (Mo -N-2(+)) keeps microcrystalline after annealing at 600 degrees C and perfor ms excellent diffusion barrier against Cu atoms at 700 degrees C for 30 min . The stress evolution of the Mo-N-2(+) thin him during the annealing proce ss indicates that highly compressive stress changes to low tensile stress a t 600 degrees C for 30 min.