Ultra-thin metallic glass film of Zr–Cu–Ni–Al–N as diffusion barrier for Cu–Si interconnects under fully recrystallized temperature

Abstract

TFMG of Zr–Cu–Ni–Al–N around 10 nm thick has been shown that it could be used as a diffusion barrier due to material’s thermal properties, e.g. glass transition temperature, and super-cooled region. A tri-layered structure was demonstrated to simulate the interconnects with TFMG inserted between Cu and Si, yet the thickness can be reduced from 10 nm to approximate 2.5 nm to test the limitation of Zr–Cu–Ni–Al–N TFMG suppressing the atomic migration of Cu diffused into Si. This can be achieved by rapid temperature annealing under the fully recrystallized temperature for 30 min, with a protective atmosphere to avoid contributions of unfavorable chemical reactions. Using XRD, ESCA and HR-TEM, the strong stability of Zr–Cu–Ni–Al–N TFMG can be revealed as a robust diffusion barrier.