Application of Cu–C and Cu–V alloys in barrier-less copper metallization

Abstract Cu-alloy seed layers have been applied to barrier-less copper metallization to improve the thermal stability. The barrier property and thermal stability of Cu alloys with smaller atomic size element C and larger size element V were both studied for comparison. Thin Cu–C and Cu–V films were deposited onto SiO 2 /Si substrates by magnetron sputtering and vacuum-annealed. After annealing at 500 °C, resistivity values of the Cu–C and Cu–V films reduced to 3.1 and 4.5 μΩ·cm, respectively. For Cu–C/SiO 2 /Si and Cu–V/SiO 2 /Si samples, a self-formed thin layer was detected at the interface. No inter-diffusion was observed between the Cu-alloy and SiO 2 layers. The Cu–V/SiO 2 /Si system lost its integrity at 600 °C, the failure temperature of the Cu–C/SiO 2 /Si system was 700 °C. While the pure Cu/SiO 2 /Si samples failed after 500 °C annealing. The Cu–C and Cu–V systems reflected improved barrier performance and thermal stability compared with pure Cu contact systems.