Thermal Stresses, Interfacial Reactions and Microstructures of Al/Ti and Al/TiN Thin Films Encapsulated by SiOF

Abstract

AbstractVariations in stress and grain size of Ti- and TiN- capped Al thin films passivated by fluorinated silicon dioxide (SiOF) during repetitive thermal cycling are investigated. The amount of stress relaxation, elastic and plastic behavior of these thin film structures are compared. Ti and TiN cap layers strengthen the single Al film significantly while the presence of SiOF induces plastic deformation of metal layers. Less grain growth is associated with a dielectric passivated Al film. The penetration of fluorine into Al upon annealing can be reduced by a TiN barrier layer.