An important application of ferroelectric films is their incorporation into dynamic random-access memories (DRAMs) as the storage node capacitor dielectric. Dynamic random-access memories represent a large market that is experiencing strong growth, but they are particularly significant as the technology leader for semiconductor devices. As products move to higher and higher integration density, new developments are first introduced in DRAMs. The steady trend toward higher density has placed severe demands on the device designs, particularly with respect to “squeezing” the capacitor into the available space.

We have analyzed the leakage behavior of polycrystalline MOCVD (Ba,Sr)TiO3 thin films as a function of both temperature and field. Of the possible mechanisms, thermionic (Schottky) emission gives a self-consistent description of the temperature and field dependencies of the true leakage current for fields in the range of 240–970 kV/cm, and yields realistic barrier heights of 1.2 eV for Pt as the cathode material. For film thicknesses of interest for use in DRAMs, the capacitance-voltage characteristics are explained via Landau-Ginzburg-Devonshire theory. Preliminary resistance degradation studies are also discussed.

The use of high-resolution electron microscopy in the study of ceramic materials is illustrated with examples from current research. Particular emphasis is placed on the preparation of the sample and the difficulties in interpretation which may result from the techniques which are necessary for these hard, chemically inert materials.

The earliest stages of epitaxy between metals and ceramics have been characterized using a novel transmission electron microscope experiment. Metal particles were deposited onto ceramic substrates which were previously thinned to electron transparency. Illustrations of epitactic relations, the influence of surface defects on particle nucleation and the growth of metal particles on single-crystal ceramic substrates are provided for the Cu / A12O3, W / β-SiC and Cu / MgO systems.