A ferroelectric device includes a bottom electrode on which are formed ferrocapacitor
elements and, over the ferroelectric elements, top electrodes. The bottom electrodes
are connected to lower layers of the device via conductive plugs, and the plugs
and bottom electrodes are spaced apart by barrier elements of Ir and/or IrO2.
The barrier elements are narrower than the bottom electrode elements, and are formed
by a separate etching process. This means that Ir fences are not formed during
the etching of the bottom electrode. Also, little Ir and/or IrO2 diffuses
through the bottom electrode to the ferroelectric elements, and therefore there
is little risk of damage to the ferroelectric material.