Effect of TiN substrate plasma treatment on copper chemical vapor deposition

Abstract

In this study, we investigated copper chemical vapor deposition (Cu CVD) on TiN substrates with respect to the effects of various plasma treatments. The Cu films deposited on the Ar-, H(2)-, and Ar+H(2)-plasma-treated TiN substrates all exhibit favorable properties over films deposited on the as-deposited TiN substrate. These include a smaller wetting angle of Cu nucleation and thus a smoother film surface, and an increased (111)-preferred orientation. However, the Cu films deposited on the plasma-treated substrates all exhibit a slightly higher resistivity, presumably due to a small grain size. With postdeposition thermal annealing at 400degreesC, the surface roughness of the Cu films and the Cu(111)/Cu(200) reflection ratio were both improved. We consider that a combined process including an Ar+H(2) plasma substrate treatment prior to Cu film deposition and a postdeposition thermal annealing is favorable for achieving a low surface roughness and high (111)-oriented Cu film deposition.