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Capacitance-voltage curves for the Al/polyimide (PI)/multilayered Ni1-xFex nanoparticle array/PI/p-Si (100) devices at 300 K showed that the flatband voltage shift of the metal-insulator-semiconductor capacitor was affected by the value of sweep voltage, indicative of the variations in the charged electron number in the multiple-stacked Ni1-xFex nanoparticle arrays in the floating gate. Current-voltage results showed that the electron charging and discharging in the Ni1-xFex nanoparticles were attributed to thermionic emission and Fowler-Nordheim tunneling, respectively. The multilevel charging and discharging mechanisms of vertically stacked Ni1-xFex self-assembled nanoparticle arrays embedded in PI layers are described on the basis of the experimental results. [ABSTRACT FROM AUTHOR]

Self-assembled Ni1-xFex nanoparticles embedded in a polyimide (PI) matrix were formed by curing Ni1-xFex thin films with PI precursor layers. Transmission electron microscopy images and selected area electron-diffraction patterns showed that Ni1-xFex nanocrystals were created inside the PI layer. Capacitance-voltage measurements on Al/PI/nanocrystalline Ni1-xFex/PI/n-Si structures at 300 K showed a metal-insulator-semiconductor behavior with a large flatband voltage shift due to the quantum confinement effect of the Ni1-xFex nanocrystals in spite of the possible existence of a thick tunnel PI layer, and conductance-voltage measurements showed a broad conductance peak around the flatband voltage. The present results suggest that self-assembled Ni1-xFex nanocrystals embedded in a PI layer hold promise for potential applications in nonvolatile flash memories with floating gates consisting of Ni1-xFex nanocrystals embedded in a PI layer. [ABSTRACT FROM AUTHOR]

Electrical and chemical characteristics of metal-oxide semiconductor field-effect transistors (MOSFETs) prepared by low-thermal-budget (∼600 °C) NH[sub 3] post-deposition annealing of HfSiON gate dielectric have been investigated. Compared to control Hf-silicate, HfSiON showed excellent thickness scalability, low leakage current density (J), and superior thermal stability. With proper annealing-time optimization, effective oxide thickness as low as 9.2 Å with Or< 100 mA/cm² at gate voltage V[sub g] = -1.5 V has been achieved. C-V hysteresis of HfSiON MOSFET was found to be small (<20 mV). Unlike NH[sub 3] surface nitridation (NH[sub 3] pre-treatment prior to Hf-silicate deposition), no degradation in G[sub m] (transconductance), I[sub d]-V[sub g], (drain current-gate voltage), or I[sub d] - V[sub d] (drain current-drain voltage) characteristics has been observed. [ABSTRACT FROM AUTHOR]

We report on the temperature dependence of the critical current (Ic) near Tc for two Y-Ba-Cu-O thin films having zero-dissipation temperature (Tc) of 81 K and a Y-Ba-Cu-O thin film having Tc of 71 K. At temperatures higher than 0.9Tc, the critical current in a voltage criterion of 1 μV/cm appears proportional to (1-T/Tc)n with n≊2, and n≊1.5 in a 10 μV/cm criterion, exhibiting the dependence of n on the critical current criteria. This observation is in contrast with the report of n=1.5 by Ogale et al. [Phys. Rev. B 36, 7210 (1987)], Yuan et al. [J. Appl. Phys. 64, 4091 (1988)], and Horng et al. [Phys. Rev. B 39, 9628 (1989)], implying that n=2, the value for the superconductor-normal metal-superconductor tunneling junction of BCS superconductors near Tc must be taken into consideration to understand the intergrain tunneling process in polycrystalline high Tc thin films. [ABSTRACT FROM AUTHOR]

High-quality stoichiometric films of YBa2 Cu3 O7-x have been grown epitaxially on SrTiO3 substrates by sputtering from a stoichiometric target of hemispherical shape using a Hg vapor triode plasma. Films exhibited superconducting transitions of a width ΔT∼2.5 K, with zero resistance being achieved at 89 K. From both the x rays and the temperature dependence of the normal-state electrical resistance it can be inferred that the films contain an admixture of domains with either the c or a axes normal to the plane. [ABSTRACT FROM AUTHOR]

We have measured the critical currents in rf-sputtered YBa2Cu3O7-x thin films deposited on polycrystalline yttria-stabilized zirconia substrates as a function of temperature down to 10 K. The dependence of the granular films at low temperature indicated exponential behavior which is similar to the superconductor-normal metal-superconductor (S-N-S) type tunneling junctions. For the films with a grain size of approximately 1 μm, we observed two exponential decay constants, which suggest that Josephson junctions limiting the transport critical current are possible both at the grain boundaries and at twin boundaries. [ABSTRACT FROM AUTHOR]