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

Abstract

Results on copper metallization diffusion barriers using high-entropy alloy (HEA) nitride are reported. The HEA nitride (AlMoNbSiTaTiVZr)50 N50 is amorphous in the as-deposited state and remains its noncrystallinity up to a high temperature of 850 °C. To evaluate its diffusion barrier characteristics, Cu (AlMoNbSiTaTiVZr)50 N50 Si test structures were prepared and annealed under 750-900 °C for 30 min. The results show that the current nitride prevents the reaction between Cu and Si before its failure at 900 °C. The outstanding barrier performance and high thermal stability of amorphous structure are suggested to originate from multiprincipal-element effects. © 2008 American Institute of Physics.