ABSTRACT

In the last several years there has been a renewed interest in ferroelectric thin films for a variety of applications such as microactuators, non-volatile memories, high dielectric constant materials for DRAMs, pyroelectric detectors, etc. 1 - 3 Although our understanding for making actual devices has improved with better processing techniques and new materials, the degradation mechanisms for fatigue, retention and imprint are less well understood. With the increased experimental effort in the area of ferroelectric thin films and the already existing knowledge base on the degradation of bulk dielectrics based on similar materials, it is reasonable to predict that the defect equilibria of these materials contribute significantly to the electrical degradation of the film. In fact, many of the various models proposed for fatigue in ferroelectric materials and degradation in dielectrics are based on some type of atomistic defect, most commonly the oxygen vacancy (K£ > ) - 4 " 6 Therefore, a study of the defect chemistry and transport properties of the Pb(Zr1 _xTix)0 3 (PZT) system has been undertaken, in order to establish the prevailing defect equilibria and the nature of the transport processes at high temperatures.