Characterization and electrical properties of chemical vapor deposited ferroelectric lead titanate films on titanium.

ABSTRACT

Lead titanate thin films were deposited on titanium substrates by a chemical vapor deposition (CVD) process involving the application of vapor mixtures of Pb, ethyl titanate (Ti(C(2)H(5)O) (4)), and oxygen. Auger electron spectroscopy (AES) analyses were performed to determine the chemical composition of lead titanate films. AES analysis revealed that TiO(2) and TiO interlayers formed between the PbTiO(3) and titanium substrate. AES also showed that stoichiometry was obtained in the lead titanate film deposited at 750 degrees C, Ti(C(2)H(2)O)(4) with 0.152, an O(2) partial pressure of 0.06 atm, and a gas flow rate of 800 sccm. The lead titanate with a stoichiometric composition has a DC conductivity of 3.2x10(-12) Omega(-1)-cm(-1) at room temperature. The nonsaturating loops observed in the present investigation may be caused by TiO(2) and TiO layers between the conductive substrate and the PbTiO(3) ferroelectric film. The ferroelectric properties of the stoichiometric PbTiO(3) film included a remanent polarization of 14.1 muC/cm(3) and a coercive field of 20.16 kV/cm.