Characteristics of copper films deposited on H2-plasma-treated TaN substrate by chemical vapor deposition

Abstract

This work investigates the chemical vapor deposition Cu films deposited on the TaN substrate with and without an H 2 -plasma treatment prior to Cu film deposition and the effect of postdeposition thermal annealing. The Cu films deposited on the H 2 -plasma-treated TaN substrate have a number of favorable properties over the films deposited on the TaN substrate without the plasma treatment. These include an increased ͑111͒-preferred orientation, smoother film surface, and a larger effective deposition rate. However, the Cu films deposited on the H 2 -plasma-treated substrate have a higher electrical resistivity, presumably due to the smaller grain size. The postdeposition thermal annealing enhanced the ͑111͒-preferred orientation and decreased the resistivity of the as-deposited Cu films. We presume that the H 2 -plasma treatment, resulted in a dense and uniform distribution of hydrogen radicals adsorbed on the substrate surface, leading to the shortening of incubation time and the formation of Cu films with a smoother surface and enhanced ͑100͒-preferred orientation. A combined process including H 2 -plasma substrate treatment prior to Cu film deposition and postdeposition thermal annealing at an appropriate temperature in N 2 ambient, is proposed for the advantage of low-resistivity and high ͑111͒-oriented Cu film deposition.

First-Principles Analyses and Predictions on the Reactivity of Barrier Layers of Ta and TaN toward Organometallic Precursors for Deposition of Copper Films

“…Ta forms nitrides with a wide range of stoichiometries. Here, we have restricted ourselves to the case of the stoichiometric TaN compounds, since these are the most common nitrides for copper barrier layers. , TaN is found both in the NaCl phase and a hexagonal phase . The cubic NaCl phase is the one commonly obtained by CVD, PVD, and sputtering. , For this phase, we obtained a lattice constant of 4.45 Å, compared well with the experimental value of 4.331 Å.…”