Electrical Characterization of Ferroelectric Thin Films of Lithium Niobate on Silicon Substrates

ABSTRACTThin films (.1-.6 μm) of LiNbO3 have been deposited on silicon substrates by rf reactive sputtering. MFS (metal-ferroelectric-semiconductor) capacitor structures were created by a liftoff process which physically isolated small areas of LiNbO3. Standard MOS (metal-oxide-semiconductor) electrical characterization techniques were used to determine the resistivity and dielectric constant of the films. Short-circuit photocurrent measurements revealed both transient and steady state components attributed to a pyroelectric effect and a bulk photovoltaic effect respectively. The conduction processes in these films were examined and found to exhibit Frenkel-Poole characteristics. Ferroelectric switching at room temperature has also been observed in these films, however, the reversed orientation was not stable.