Effects of (002) beta-Ta barrier on copper chemical mechanical polishing behavior

Abstract

This study proposes that the corrosion resistance of copper film correlates well with underlying barrier's orientation. To test the hypothesis, we performed X-ray diffraction, conducted copper removal rate experiments after chemical mechanical polishing, and tested static potentiodynamic polarization. The results all show that copper deposited on strongly (002) oriented beta-Ta barrier layer demonstrated better chemical resistance against surface reaction with the slurry for strong copper (111) orientation. The findings were consistent with the result of the chronoamperometric test at 0.3 V in which the more passive film formed on the composite film with (002) beta-Ta underlying barrier. (C) 2012 Elsevier B.V. All rights reserved.