Performance of amorphization AlCrTiZrMo high entropy alloy barrier for copper metallization

A reliable ultra-thin diffusion barrier is required for Cu interconnection. High entropy alloy (HEA) films have received attention in the development of diffusion barrier materials due to their remarkable properties. Here, the dense and smooth 17 nm AlCrTiZrMo high entropy alloy amorphous film (HEAAF) is obtained by the cofilter cathode vacuum arc deposition. After annealing at 700 °C for 1 h, no Cu-silicide compounds are formed and the sheet resistance is 0.27 Ω/□, which indicated that AlCrTiZrMo HEAAF has excellent diffusion barrier performance. Such barrier temperature is comparable to some ceramic barriers. The excellent diffusion barrier performance of AlCrTiZrMo HEAAF is due to its good stability of amorphous structure and chemical stability at high temperature.