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As a transition metal chalcogenide, tantalum sulfide ( TaS x ) is of interest for semiconductor device applications, for example, as a diffusion barrier in Cu interconnects. For deposition of ultrathin nanolayers in such demanding 3D structures, a synthesis method with optimal control is required, and therefore, an atomic layer deposition (ALD) process for TaS x was developed. ALD using (tert)-butylimidotris(dimethylamido)tantalum (Ta [ N (CH 3) 2 ] 3 [ NC (CH 3) 3 ]) as the precursor and an H 2 S-based plasma as the coreactant results in linear growth of TaS x films as a function of the number of cycles for all temperatures in the range 150–400 ° C with growth per cycle values between 1.17 ± 0.03 Å and 0.87 ± 0.08 Å. Saturation of the precursor and plasma dose times, established at 300 ° C, was reached after 20 and 10 s, respectively. Variation of the table temperature or the plasma composition offers the possibility to tune the film properties. At 300 ° C, amorphous TaS 3 films were grown, while addition of H 2 to the plasma led to polycrystalline TaS 2 films. The difference in sulfur content in the films correlates to a change in resistivity, where the least resistive film had the lowest S content. [ABSTRACT FROM AUTHOR]

In this work, the physical and electrical properties of SrxTi1-xOy (STO)-based metal-insulator-metal capacitors (MIMcaps) with various compositions are studied in detail. While most recent studies on STO were done on noblelike metal electrodes (Ru, Pt), this work focuses on a low temperature (250 °C) atomic layer deposition (ALD) process, using an alternative precursor set and carefully optimized processing conditions, enabling the use of low-cost, manufacturable-friendly TiN electrodes. Physical analyses show that the film crystallization temperature, its texture and morphology strongly depends on the Sr/Ti ratio. Such physical variations have a direct impact on the electric properties of SrxTi1-xOy based capacitors. It is found that Sr-enrichment result in a monotonous decrease in the dielectric constant and leakage current as predicted by ab initio calculations. The intercept of the EOT vs physical thickness plot further indicates that increasing the Sr-content at the film interface with the bottom TiN would result in lower interfacial equivalent-oxide thickness. [ABSTRACT FROM AUTHOR]

Induction of general anesthesia frequently induces arterial hypotension, which is often treated with a vasopressor, such as phenylephrine. As a pure α-agonist, phenylephrine is conventionally considered to solely induce arterial vasoconstriction and thus increase cardiac afterload but not cardiac preload. In specific circumstances, however, phenylephrine may also contribute to an increase in venous return and thus cardiac output (CO). The aim of this study is to describe the initial time course of the effects of phenylephrine on various hemodynamic variables and to evaluate the ability of advanced hemodynamic monitoring to quantify these changes through different hemodynamic variables. In 24 patients, after induction of anesthesia, during the period before surgical stimulus, phenylephrine 2 µg kg-1 was administered when the MAP dropped below 80% of the awake state baseline value for > 3 min. The mean arterial blood pressure (MAP), heart rate (HR), end-tidal CO2 (EtCO2), central venous pressure (CVP), stroke volume (SV), CO, pulse pressure variation (PPV), stroke volume variation (SVV) and systemic vascular resistance (SVR) were recorded continuously. The values at the moment before administration of phenylephrine and 5(T5) and 10(T10) min thereafter were compared. After phenylephrine, the mean(SD) MAP, SV, CO, CVP and EtCO2 increased by 34(13) mmHg, 11(9) mL, 1.02(0.74) L min-1, 3(2.6) mmHg and 4.0(1.6) mmHg at T5 respectively, while both dynamic preload variables decreased: PPV dropped from 20% at baseline to 9% at T5 and to 13% at T10 and SVV from 19 to 11 and 14%, respectively. Initially, the increase in MAP was perfectly aligned with the increase in SVR, until 150 s after the initial increase in MAP, when both curves started to dissociate. The dissociation of the evolution of MAP and SVR, together with the changes in PPV, CVP, EtCO2 and CO indicate that in patients with anesthesia-induced hypotension, phenylephrine increases the CO by virtue of an increase in cardiac preload. [ABSTRACT FROM AUTHOR]

Performance and negative-bias temperature instability (NBTI) on atomic-layer-deposited HfSiON metal-gated pMOSFETs are investigated. The impact of nitrogen incorporation either with plasma nitridation or NH3 anneal is studied and compared to the nonnitrided stacks. The capacitance equivalent thickness reduction that is observed in nitrided stacks is compensated by the slight decrease of the hole mobility for the same gate overdrive, resulting in no improvement of the performance. On the other hand, it is shown that nitridation strongly enhances NBTIs in these devices. Based on these results, the necessity of nitrogen incorporation in thin HfSiON/metal gate stacks should be reconsidered. [ABSTRACT FROM AUTHOR]

The alignment of the conduction and valence bands in metal/mixed Hf–Ta oxide/silicon structures was determined as a function of oxide composition using intrinsic photoconductivity and internal photoemission measurements. With increasing Ta content in the Hf–Ta oxide from 0% to 100%, the band gap gradually decreases from 5.6 to 4.2–4.4 eV. This is predominantly associated with the downshift of the lowest conduction band derived from the 5d* unoccupied orbitals of the metal cations. This indicates a significant mixing of the states belonging to the Ta and Hf subnetworks, and suggests the possibility of oxide band gap control in the mixed oxides of metals from the same period of elements. [ABSTRACT FROM AUTHOR]

We have measured minority-carrier lifetimes of up to 4.9 μs in GaAs layers that have been grown by low-pressure organometallic vapor phase epitaxy. These lifetimes, representing a major improvement compared with previously obtained results, are governed by radiative recombination processes. Carbon incorporation during crystal growth at low arsine partial pressures is of prime importance in understanding the origin of these very long lifetimes. [ABSTRACT FROM AUTHOR]