Radiation effects on switching kinetics of three-dimensional ferroelectric capacitor arrays

Effects of x-ray irradiation combined with either bias voltage or bipolar electrical cycling were analyzed on three-dimensional ferroelectric capacitor arrays developed for highly reliable ferroelectric random access memories. Using dedicated experimental setup enabling in situ measurements, switching kinetics were followed over several hours of exposure. Polarization changes and voltage shifts were interpreted in considering interactions between trapping of photoinduced charges and ferroelectric domain structure, which depends upon the capacitor geometry and external field. In memorylike arrays in "written" or "writing" states, high dose of x rays accelerates fatiguelike (polarization reduction) and/or imprintlike (voltage shift) mechanisms that may perturb normal memory operations. (c) 2006 American Institute of Physics.