Anion Effects on Cu–benzotriazole Film Formation

Abstract

We examine the effect of different anions in solutions containing benzotriazole (BTA) on the Cu removal rate during chemical mechanical planarization (CMP). In solutions containing both and BTA, the Cu removal rate is nearly a factor of twenty lower than in solutions containing either or BTA alone. As-grown BTA films from solutions containing different anions are characterized using atomic force microscopy, ellipsometry, Raman spectroscopy, mass spectrometry, and open-circuit-potential measurements. Films grown from halide-containing solutions are found to be considerably thicker than those grown from other anions. The difference in Cu removal rate correlates well with the different as-grown film thicknesses.