Ferroelectric Thin-Film Devices: Failure Mechanisms and New Prototype Nano-Structures

Several fundamental physics problems concerning ferroelectric thin films are discussed with direct application to industry problems. The first is a model of dielectric breakdown under d.c. voltage stressing, extended from single capacitor films to multilayer capacitors (MLCs). The second is an analysis of flash-over (arcing) breakdown in MLCs, including those with base metal electrodes (Ni). The third is the demonstration that any equivalent circuit model for real ferroelectric memories (FRAMs) must include a constant phase element (CPE). We then consider novel new prototype devices with industry potential for commercialization: three-dimensional [3D] DRAM capacitor trenches; piezoelectric nanotubes; and carbon nano-wire arrays with ferroelectric tips.