N2+ implantation approaches for improving thermal stability of Cu/Mo/Si contact structure

Abstract

We have suggested N2+ ion modification method to improve the thermal stability of Mo thin film by implanting 3 × 1017 N2+ ions/cm2 with very low acceleration energy of 20 keV. The Mo film modified by N2+ ions (Mo-N2+) keeps microcrystalline after annealing at 600°C and performs excellent diffusion barrier against Cu atoms at 700°C for 30 min. The stress evolution of the Mo-N2+ thin film during the annealing process indicates that highly compressive stress changes to low tensile stress at 600°C for 30 min. ？1999 Publication Board, Japanese Journal of Applied Physics.