IMPROVEMENT OF TA DIFFUSION BARRIER PERFORMANCE IN CU METALLIZATION BY INSERTION OF A THIN ZR LAYER INTO TA FILM

In order to increase the failure temperature of Ta diffusion barrier f or Cu, we investigated the effect of insertion of a thin Zr layer into Ta film with/without ion bombardment on Ta diffusion barrier performa nce in Cu metallization. The insertion of a thin Zr layer into Ta film improved barrier properties significantly when the Ta/Zr/Ta barrier l ayers were deposited with concurrent ion bombardment. The significant improvement of Ta diffusion barrier properties by insertion of a thin Zr layer into Ta film with ion bombardment was attributed to the densi fication of grain boundaries in Ta/Zr/Ta films and the formation of an intermixing layer between Ta and Zr by ion bombardment, followed by t he reduction of fast diffusion of Cu through Ta/Zr/Ta films. (C) 1998 American Institute of Physics.