Investigation of Zr–Si–N∕Zr bilayered film as diffusion barrier for Cu ultralarge scale integration metallization

Abstract

The effectiveness of ZrSiN∕Zr bilayered films to serve as diffusion barriers in Cu∕Si contacts has been investigated. Annealing studies for Cu∕ZrSiN∕Zr∕Si contact systems were carried out in N2∕H2(10%) ambient. X-ray diffraction data suggest that Cu film has preferential (111) crystal orientation and Cu silicide cannot be observed up to 700°C. Scanning electron microscopy micrographs show that the Cu film was integrated and free from agglomeration after annealing at 700°C. Auger electron spectroscopy depth profiles of the Cu∕ZrSiN(10nm)∕Zr(20nm)∕Si samples have no noticeable change except Zr silicide grows with annealing temperature up to 700°C. The results indicate excellent barrier property for ZrSiN(10nm)∕Zr(20nm) bilayer structure for Cu metallization.