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We present an infrared spectroscopy and X-ray diffraction study of hafnium oxide gate dielectric films deposited from hafnium tetra–tert-butoxide, Hf(OC(CH3)3)4. We characterize the crystal phase as a function of thickness and detect the chemical state of impurities in this high-permittivity (high-κ) material. The HfO2 films are composed of monoclinic crystallites in an amorphous matrix. The crystalline fraction increases with increasing film thickness. Infrared spectroscopy is used to obtain information about impurities, which may help to uncover the nature of electrical defects. We detect and quantify for instance the presence of incorporated hydroxyl groups or water that may be responsible for the deviation from ideal HfO2 stoichiometry. The concentration of residual C&z.sbnd;H bonds is low. However, carbon is incorporated in an oxidized form, possibly as carbonate. [Copyright &y& Elsevier]

Examines synthesis and characterization of homologous tetranuclear (DME)4Ln4SePh)8 clusters (Ln = Sm, Yb, Nd(III)/Yb(II),Sm(III)/Yb(II); DME = dimethoxyethane). Reasons for analyzing stepwise sequence of clusters; Revelation of a square array of four metal ions; Relevance of cluster intermediates on Ln chalcogenido cluster synthesis.

A near-equiatomic FePt face-centered-cubic alloy has been grown by electrodeposition onto Cu(001). Annealing at 450 °C results in the onset of a A1 fcc to L10 face-centered-tetragonal phase transformation with a dominant FePt(001)<100>∥Cu(001)<100> recrystallization texture, possibly driven by the reduced ordering temperature in an FePtCu intermixed interface region. Further annealing at 650 °C leads to a more complete transformation, and magnetic measurements indicate that high perpendicular coercivities, of up to 10 kOe, are accessible through the recrystallization reaction. The magnetic and structural properties reported in this work may allow electrodeposited FePt to play a leading role in future ultrahigh-density patterned perpendicular magnetic media. [ABSTRACT FROM AUTHOR]

With the rapid progress of spintronic devices, spin-logic concepts hold promises of energy-delay conscious computation for efficient logic gate operations. We report on the electrical characterization of domain walls in interconnected magnetic tunnel junctions. By means of spin-transfer torque effect, domains walls are produced at the common free layer and its propagation towards the output pillar sensed by tunneling magneto-resistance. Domain pinning conditions are studied quasi-statically showing a strong dependence on pillar size, ferromagnetic free layer width and inter-pillar distance. Addressing pinning conditions are detrimental for cascading and fan-out of domain walls across nodes, enabling the realization of domain-wall-based logic technology. [ABSTRACT FROM AUTHOR]

In this work, we evaluate the material properties of graphene and assess the potential application of graphene to replace copper wires in Back-End-Of-Line (BEOL) interconnects. Based on circuit and system-level simulations, high restrictions are imposed to graphene with respect to contact resistance and mean free path. Experimentally we evaluate single and multi-layer graphene wires and we measure carrier mean free paths (MFPs) above ~ 110 nm. However, contact engineering will be the key issue for integration of graphene as interconnect. [ABSTRACT FROM AUTHOR]

Achieving low resistance contacts to graphene is a common concern for graphene device performance and hybrid graphene/metal interconnects. In this work, we have used the circular Transfer Length Method (cTLM) to electrically characterize Ag, Au, Ni, Ti, and Pd as contact metals to graphene. The consistency of the obtained results was verified with the characterization of up to 72 cTLM structures per metal. Within our study, the noble metals Au, Ag and Pd, which form a weaker bond with graphene, are shown to result in lower contact resistance (Rc) values compared to the more reactive Ni and Ti. X-ray Photo Electron Spectroscopy and Transmission Electron Microscopy characterization for the latter have shown the formation of Ti and Ni carbides. Graphene/Pd contacts show a distinct intermediate behavior. The weak carbide formation signature and the low Rc values measured agree with theoretical predictions of an intermediate state of weak chemisorption of Pd on graphene. [ABSTRACT FROM AUTHOR]