INFLUENCE OF DISTURBED LAYERS ON THE DIELECTRIC PROPERTIES OF FERROELECTRIC THIN FILM CAPACITORS

Capacitor ferroelectric structures are the basis of many modern microelectronic devices, including non-volatile memory, piezoelectric micro-actuators, sensors etc. Miniaturization of such devices requires a reduction in the ferroelectric layer thickness, which reduces the major characteristics of ferroelectric structures, such as permittivity, remanent polarization, Curie temperature, and others. Such thickness dependences are usually explained by the "disturbed layer" model, which assumes the existence of a nonferroelectric (disturbed, dead) layer with uniform thickness on the ferroelectric-metal interface. In this paper, dielectric characteristics of the capacitor structures based on dense and porous lead zirconate titanate (PZT) films with different thicknesses are studied. Modeling of permittivity dependencies as a function of the ferroelectric film thickness considering the presence of disturbed layers is performed. The optimal modeling technique is proposed