Preparation of Al-doped PbTiO3 Thin Films by Metalorganic Chemical Vapor Deposition and Their Characterization

Abstract

Alminium-doped PbTiO3, Pb(Al, Ti)O3, thin films were prepared by metalorganic chemical vapor deposition from the Pb(C11H19O2)2–Al(O·n-C3H7)3–Ti(O·i-C3H7)4–O2 system. Al content of the film could be controlled only by changing the input gas concentration of Al(O·n-C3H7)3, and was independent of the deposition temperature from 400 to 620°C. Lattice parameter change of the film showed that the solubility limit of Al atoms into perovskite phase existed in the vicinity of 8 at.%. Leakage current density of the film deposited on (111)Pt/Ti/SiO2/(100)Si substrate decreased with increasing Al content up to 33 at.%. The thin film with 4.1 at.% Al content showed ferroelectricity, and the twice the values of remanent polarization (2Pr) and the coercive field (2Ec) were 8.5 µC/cm2 and 90 kV/cm, respectively. The epitaxial Pb(Al, Ti)O3 thin film was deposited on (110)SrRuO3∥(110)SrTiO3 substrate, and the 2Pr and the 2Ec values were 27.5 µC/cm2 and 200 kV/cm, respectively.