A ferroelectric capacitor device, such as an FeRAM device is formed of a substrate
having one or more contact plugs extending therethrough, and a first interlayer
dielectric layer formed on the substrate. A spacer layer is formed on the first
interlayer dielectric layer, a first oxygen barrier layer is formed on the spacer
layer and a buffer layer is formed on the first oxygen barrier layer. A layer of
liner material is formed on the buffer layer between the buffer layer and the contact
plugs and a dielectric layer is sandwiched between a first electrode and a second
electrode. A second oxygen barrier layer is applied to the device. The spacer layer
should prevent any oxidation from reaching the interface between the liner material
and the contact plugs as this interface is located beneath the first oxygen barrier
layer. As a result, the electrical contact is not damaged.