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The interface between a dielectric thin film and a metal electrode is studied to improve reliability as well as electrical properties of the metal–insulator–metal (MIM) capacitor in dynamic random‐access memory (DRAM) devices. The interfacial layers between a dielectric thin film and a metal electrode play important functional roles such as increasing the electrical barrier or preventing oxygen defects in high‐k dielectrics. By introducing an electrical barrier layer or a sacrificial layer at the metal–dielectric interface for engineering the electronic band, lattice, or dipole, various effects could be confirmed such as the conduction band offset (CBO), bandgap or mismatch modulation for controlling the dielectric loss depending on the AC frequency or leakage current of MIM capacitors. Upon the insertion of Al2O3 as an electrical barrier layer, CBO increased because of the band engineering. Further, upon the insertion of TiO2 as a sacrificial layer at the interface, CBO increased because of the dipole formation at the interface, attributed to the difference in electronegativity. Thus, a robust MIM capacitor for DRAM that maintains a low leakage current and has improved reliability which is realized using the proper combination of interfacial layers. [ABSTRACT FROM AUTHOR]

Abstract: We report on growth-mode transitions in the growth of SrRuO3 thin films on atomically flat Ti4+ single-terminated SrTiO3 (111) substrates, investigated by reflection high-energy electron diffraction and atomic force microscopy. Over the first ~9 unit cells, the dominant growth mode changes from island to layer-by-layer for the growth rate of 0.074 unit cells/s and the growth temperature of 700°C. Moreover, in the course of growing SrRuO3 films, the governing growth mode of interest can be manipulated by changing the growth temperature and the growth rate, which change allows for the selection of the desired layer-by-layer mode. The present study thus paves the way for integrations of SrRuO3 thin layers into (111)-orientated oxide heterostructures, and hence multi-functional devices, requiring control of the sharp atomic-level interfaces and the layer-by-layer growth mode. [Copyright &y& Elsevier]

Abstract: We successfully grew SrFeO3−δ thin films in a layer-by-layer manner by pulsed laser deposition (PLD). When the SrFeO3−δ films were directly grown on atomically flat Ti4+-terminated SrTiO3 (111) substrates, the oscillatory reflection-high-energy-electron-diffraction intensity was completely damped after its third oscillation. By contrast, the introduction of SrRuO3 buffer layers onto the SrTiO3 substrates allowed the SFO thin films to grow in a layer-by-layer manner over a far-extended thickness range. The probable mechanism of that growth is electronic reconstruction-reduced electrostatic potential divergence. With that result, the present study provides a means of growing pseudocubic (111)-oriented SrFeO3−δ heterointerfaces, making possible the fabrication of high-functionality oxide heterostructures. [Copyright &y& Elsevier]