Preparation of Al-doped PbTiO3 thin films by metalorganic chemical vapor deposition and their characterization

Alminium-doped PbTiO3, Pb(Al,Ti)O-3, thin films were prepared by metalorgan ic chemical vapor deposition from the Pb(C11H19O2)(2)-Al(O.n-C3H7)(3)-Ti(O. i-C3H7)(4)-O-2 system. Al content of the him could be controlled only by ch anging the input gas concentration of Al(O.n-C3H7)(3), and was independent of the deposition temperature from 400 to 620 degrees C. Lattice parameter change of the film showed that the solubility limit of Al atoms into perovs kite phase existed in the vicinity of 8 at.%. Leakage current density of th e film deposited on (111)Pt/Ti/SiO2/(100)Si substrate decreased with increa sing Al content up to 33 at.%. The thin film with 4.1 at.% Al content showe d ferroelectricity, and the twice the values of remanent polarization (2P(r )) and the coercive field (2E(c)) were 8.5 mu C/cm(2) and 90 kV/cm, respect ively. The epitaxial Pb(Al,Ti)O-3 thin film was deposited on (110)SrRuO3 pa rallel to (110)SrTiO3 substrate, and the 2P(r) and the 2E(c) values were 27 .5 mu C/cm(2) and 200 kV/cm, respectively.