Thermally stable amorphous (AlMoNbSiTaTiVZr)50N50 nitride film as diffusion barrier in copper metallization

Results on copper metallization diffusion barriers using high-entropy alloy (HEA) nitride are reported. The HEA nitride (AlMoNbSiTaTiVZr)(50)N-50 is amorphous in the as-deposited state and remains its noncrystallinity up to a high temperature of 850 degrees C. To evaluate its diffusion barrier characteristics, Cu/(AlMoNbSiTaTiVZr)(50)N-50/Si test structures were prepared and annealed under 750-900 degrees C for 30 min. The results show that the current nitride prevents the reaction between Cu and Si before its failure at 900 degrees C. The outstanding barrier performance and high thermal stability of amorphous structure are suggested to originate from multiprincipal-element effects. (c) 2008 American Institute of Physics.