High temperature stability of Zr–Si–N diffusion barrier in Cu/Si contact system

Abstract

Zr–Si–N thin films were deposited on silicon substrates by radio frequency reactive magnetron sputtering (RFMS) technique. Subsequently, Cu films were sputtered on the Zr–Si–N thin films by direct current-pulse magnetron sputtering (DCPMS). The Zr–Si–N films and Cu/Zr–Si–N/Si contact systems were analyzed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), four-point probe sheet resistance measurements, scanning electron microscopy (SEM) and Auger electron spectroscopy (AES), respectively. It was found that the sheet resistances of Cu/Zr–Si–N/Si contact systems annealed in H 2/N 2 gas mixture were lower than those of as-deposited specimens even after annealing at 800 °C for 1 h. Zr–Si–N thin film showed excellent barrier property so that the Cu/Zr–Si–N/Si contact systems keep the structures unchanged and Cu 3Si phase could not be detected. Amorphous Zr–Si–N thin film was considered to be a promising candidate in Cu diffusion barrier due to its high thermal stability.