Self-polarization control of radio-frequency-sputtered lead zirconate titanate films

The phenomenon of self-polarization in sputtered lead zirconate titanate (PZT) thin films was analyzed. Vacancy formation enthalpies of PZT compounds were estimated for the first time considering a significant amount of covalent binding in PZT crystals. The mobility of vacancies was estimated by a ballistic migration process with a jump time inversely proportional to the phonon frequency. A value as low as 0.12 eV results for the oxygen vacancy enthalpy of migration, which is also responsible for fatigue in PZT capacitors in silicon microelectronic dynamic random access memories.