Binary and complex oxide thin films for microelectronic applications: An insight into their growth and advanced nanoscopic investigation

Innovative dielectric materials are of increasing interest in several microelectronic devices. Here, an overview of different MOCVD approaches to fabricate binary and complex oxide thin films with dielectric properties is presented. The growth of three types of oxide thin films, namely Pr2O3, NiO and CaCu3Ti4O12, has been discussed. In particular the growth of Pr2O3 films has been optimized on (001) Si substrates for CMOS applications. In this case, because of the wide numbers of possible Pr-oxide phases, an accurate control of oxygen partial pressure was mandatory. NiO thin films have been grown on (0001)SiC and (0001)AlGaN/GaN wide bandgap semiconductors. The appropriate conditions for the epitaxial growth have been found in order to improve the quality of the interface. Finally, complex oxide CaCu3Ti4O12 thin films have been grown on single crystal perovskite substrates as well as on technological electrodes to be applied in wireless and Rf circuits. An appealing approach based on the use of a multicomponent precursor source has been optimized and both epitaxial and polycrystalline films have been deposited. In all cases, special emphasis has been placed upon the importance of suitable precursors, deposition parameters and interfacial characterization. In addition, dielectric properties have been correlated to structural and compositional characteristics by scanning probe microscopy with conductive tips, which has been used to image defects inside the grains or heterogeneities at the grain boundaries.