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Transition metal compounds showing a metal-insulator transition (MIT) show complex behavior due to strongly correlated electron effects and offer attractive properties for nano-electronics applications, which cannot be obtained with regular semiconductors. MIT based nano-electronics, however, remains unproven, and MIT devices are poorly understood. We point out and single out one of the major hurdles preventing MIT-electronics: obtaining a high Off resistance and high On-Off resistance ratio in an MIT switch. We show a path toward an MIT switch fulfilling strict Off and On resistance criteria by: (1) Obtaining understanding of the VO2-interface, a protoypical MIT material interface. (2) Introducing a MIT tunnel junction concept to tune switch resistances. In this junction, the metal or insulating phase of the MIT material controls how much current flows through. Adapting the junction's parameters allows tuning the MIT switch's Off and On resistance. (3) Providing proof of principle of the junction and its switch resistance tuning capability, experimentally in two forms. (4) Showing theoretically how stringent Off and On resistance specifications can be fulfilled. The prototypical VO2 MIT results in an abrupt change in bulk electrical resistivity at ∼68 °C. We show that the VO2 MIT manifests itself in an abrupt interfacial transition of current across a VO2-barrier interface forming a tunnel junction. In a first tunnel junction form, a two orders of magnitude abrupt change in contact resistivity induced by the bulk MIT is shown in VO2-metal contact structures. VO2-metal contact properties are discussed in detail, and the work function of VO2 is found to be 5.2eV(25 °C)-5.3eV(90 °C). In a second junction form, an abrupt change in tunneling current of up to an order of magnitude caused by the bulk MIT is shown to be present in VO2-insulator-metal capacitor structures with atomic layers deposition (ALD) Al2O3 and HfO2 barrier layers. The capacitors show the feasibility of using the MIT to switch a component to a high Off resistance state. Current and capacitance-voltage characteristics of the capacitors are analyzed as well as voltage or field dependent MITs at VO2 interfaces. The abrupt change in current across the VO2 interface is shown to be driven by the change in free carriers in bulk VO2 across the MIT. [ABSTRACT FROM AUTHOR]

Analysis of electron states in nanometer-thin NiO layers grown by metallo-organic chemical vapor deposition on SiO2 or Al2O3 by means of spectroscopic ellipsometry and internal photoemission measurements points to the presence of a metal-like electron density, in correlation with the enhanced electrical conductivity of the films. These metallic states are suggested to be related to Ni clusters formed by partial reduction of NiO by hydrogen-containing by-products of the deposition reaction. [ABSTRACT FROM AUTHOR]

TaCN layers were deposited using metal-organic chemical-vapor deposition for applications as metal gate electrodes in p-type metal-oxide-semiconductor (pMOS) devices. The films were formed by thermal decomposition of tertiary-amylimido-tris(dimethylamido)tantalum (TAIMATA®) between 400 and 600 °C. The composition was dependent on the growth temperature with increasing C and decreasing N content at higher temperature. Films grown below 500 °C were nearly amorphous and became weakly polycrystalline with a cubic structure at higher growth temperature. The layer density was ∼8.1 g/cm3, about half of the TaCN bulk density. Grazing-incidence x-ray diffraction and transmission electron microscopy showed that the films consist of small polycrystalline grains in an amorphous matrix. The resistivity was found to decrease with increasing growth temperature. Lowest resistivity values were around 1 mΩ cm for films grown at 600 °C. The films formed an ∼4 nm thick insulating surface oxide, which leads to a thickness dependence of the film resistivity. Oxygen was also found to diffuse slowly into the bulk metal, which leads to a resistivity aging effect. The effective work function of the TaCN films was found to be 4.8 eV on HfSiO4 and HfSiON and to shift weakly by high thermal budget annealing toward the Si valence band, reaching 4.9 eV on HfSiO4. [ABSTRACT FROM AUTHOR]

Insight in the thermal degradation phenomena and the relation to phase transformation is presented for cobalt disilicide (CoSi2) on narrow polysilicon lines (linewidth ranging from 30 nm to 1 μm) using electrical and morphological analysis in the temperature range 650–900 °C. When polysilicon lines are scaled laterally to 30 nm, an abrupt CoSi2 sheet resistance increase (>1000 Ω/sq) is observed, which is attributed to silicide agglomeration. At localized positions along the 30-nm Co-silicided lines, Si/silicide layer inversion is observed. At low formation temperature (650 °C), no agglomeration phenomena occur, but incidentally the transition from CoSi into CoSi2 is delayed on the 30-nm-wide polysilicon structures to such an extent that the CoSi2 growth virtually stops. Only using nitrogen implantation through CoSi and a CoSi2 formation temperature of 900 °C, low sheet resistance values are obtained for 35-nm-wide polysilicon lines. Based on the results obtained in the present work, we propose that the abrupt increase in the CoSi2 sheet resistance for the narrow polysilicon lines is a consequence of a decrease in the availability of nucleation sites leading to the reduction of the CoSi/CoSi2 transformation rate, which, in turn, results in the agglomeration of Co silicide at elevated temperature. [ABSTRACT FROM AUTHOR]

Presents information on a study which showed the template mechanism that takes place in the molybdenum doped poly-silicon/titanium system using high resolution transmission electron microscopy. Experimental details; Results and discussion; Conclusions.

Provides information on a study that examined the solidification of silicon-arsenic alloys induced by pulsed-laser melting at regrowth velocities where the partition coefficient is close to unity. Experimental techniques; Data analysis; Results and discussion on the study; Conclusions.

Presents a study that analyzed lattice distortions and their correlations to characteristics of the superconducting transitions in 123 thin films grown in situ by sequential ion beam sputtering. Methods and procedures used in the preparation of the films; Analysis of transition temperatures as a function of the c-axis lattice parameter; Expression for the line broadening due to inhomogeneous lattice distortions along the c-direction.

Analysis of photodepopulation of electron traps in HfO2 films grown by atomic layer deposition is shown to provide the trap energy distribution across the entire oxide bandgap. The presence is revealed of two kinds of deep electron traps energetically distributed at around Et ≈2.0 eV and Et ≈3.0 eV below the oxide conduction band. Comparison of the trapped electron energy distributions in HfO2 layers prepared using different precursors or subjected to thermal treatment suggests that these centers are intrinsic in origin. However, the common assumption that these would implicate O vacancies cannot explain the charging behavior of HfO2, suggesting that alternative defect models should be considered. [ABSTRACT FROM AUTHOR]