Method of fabrication of an FeRAM capacitor and an FeRAM capacitor formed by the method

摘要

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.