Application of amorphous Cu–Zr binary alloy as a diffusion barrier in Cu/Si contact systems

Abstract

Thermally stable Cu/Si contact systems using an amorphous binary alloy of Cu0.6Zr0.4 with a relatively low resistivity of ∼150 μΩ cm as a diffusion barrier have been developed. The application of the stable compound ZrN in the Zr/Cu/Cu–Zr/ZrN/Si contact system effectively suppresses the interfacial reactions up to a temperature of 550 °C, which is higher than the crystallization temperature of the Cu–Zr amorphous alloy, ∼500 °C. By designing the contact system with the Cu-containing amorphous alloy Cu–Zr and the stable barrier compound ZrN, also a compound of a constituent material of the amorphous alloy, we can obtain an effective diffusion barrier in the Cu/Si contact system.