Effects of the underlayer substrates on copper chemical vapor deposition

Abstract

Copper chemical vapor deposition (Cu CVD) on different substrates, including TiN, Ta, and TaN, was studied with regard to the physical property, nucleation, and adhesion of the deposited Cu films. The Cu film deposited on TiN substrate has a number of favorable properties over the films deposited on Ta and TaN substrates: lower electrical resistivity, lower impurity contamination, and higher (111)-preferred orientation. Moreover, CVD of Cu films on TiN substrate has a shorter incubation time and better film adhesion. From the viewpoint of adhesion, microstructure, and physical properties of the Cu film, we may conclude that TiN is a better underlayer substrate than Ta and TaN for Cu CVD. (C) 2002 American Vacuum Society.