Chemically vapor deposited Cu films on Ar-plasma-treated TiN substrate

Abstract

Chemically vapor deposited (CVD) Cu films on TiN substrates with and without Ar plasma treatment prior to Cu film deposition and the effects of postdeposition thermal annealing were investigated. Cu films deposited on an Ar-plasma-treated TiN substrate have a number of favorable properties over films deposited on a TiN substrate without the plasma treatment. These include a smoother film surface, regular arrangement of Cu grains, and markedly increased ( 111)-preferred orientation. The postdeposition thermal annealing enhanced the (111)-preferred orientation and decreased the resistivity of the as-deposited Cu films. A combined process including Ar plasma substrate treatment prior to Cu film deposition and postdeposition thermal annealing at an appropriate temperature in N-2 ambient is proposed in order to achieve low-resistivity and highly (111)-oriented Cu film deposition. In this way, Cu films with a resistivity of 1.90muOhm.cm and a Cu(111)/Cu(200) peak ratio of 7.08 were obtained.