X-ray reflectivity studies of ferroelectric and dielectric multilayer structures

Dielectric and ferroelectric thin-film capacitors are of great importance as dynamic random-access memories (DRAM) and non-volatile random-access memories (NVRAM) for storage technology applications. Further improvements of the electrical performance of these devices require particularly a better control of thin-film engineering, since nanoscale layers of complex stoichiometry are subjected to relatively high-thermal budgets during the integration process. X-ray specular and diffuse reflectivity can provide valuable insight into current material problems of this field, e.g. structural changes and the possibility of interfacial reactions. An example is given for the annealing of thin Pb(Zr0.3Ti0.7)O3 (PZT) films on Pt/Ti-based layered electrodes. The correlation of electrical function and structural changes subsequent to electrical stress requires in situ investigations under applied electric fields. We report first experiments on Pt/PZT/Pt/Ti-films and discuss the setup of electrical in situ measurements under grazing incidence.