1.5–2.5 nm RTP gate oxides: process feasibility, properties and limitations

To support the international roadmaps' requirements, semiconductor manufacturers must develop new processing technologies, both to shrink the dimensions and to improve the performances of devices. As a consequence, gate oxidation must advance to the 1.5–2.5 nm range over the coming years, to support the sub-0.18 μm technologies. We present here an overview of the more critical concern regarding this gate oxide downscaling. The limitations of rapid thermal processed (RTP) gate dielectric for oxide thickness <2 nm are discussed in terms of process feasibility, oxide thickness determination and maximum gate leakage current. As a result, we show that oxides as thin as 1.2 nm can be processed with control of the film uniformity (range within 0.06 nm). However, we also demonstrate that the exponential increase of the gate leakage current for oxides <2 nm does not allow integrating such thin dielectric layers in present metal oxide semiconductor (MOS) devices (oxide thickness limit around 2.3 nm).     

Characterization of Fibers in an Existing Network for High Speed System (10Gb/s or Greater) Compatibility

With OC-192 communications systems being commercially available and higher bit rate systems in development, prudent telecommunications network administrators are testing their installed fibers to determine if they can be successfully used at 10 Gb/s and higher. Together with New Brunswick Telephone (NBTel), the Fiber Optics Group at UNB have tested various installed fibers and cables in the NBTel network for their losses at wavelengths of 1244, 1310, 1550, and 1625 nm, as well as for strain and polarization mode dispersion (PMD). Weather conditions, age, place of installation, and cable types have also been considered. Aging does not seem to affect the performance of the fibers. Although most fibers are high-speed system compatible when looking at attenuation measurements, about 40% of the fibers tested would not meet the 10 Gb/s OC-192 system manufacturer's design guidelines concerning PMD.     

Millimeter-Wave Spectroscopy of Methylfuran Isomers: Local vs. Global Treatments of the Internal Rotation

Methylfurans are methylated aromatic heterocyclic volatile organic compounds and primary or secondary pollutants in the atmosphere due to their capability to form secondary organic aerosols in presence of atmospheric oxidants. There is therefore a significant interest to monitor these molecules in the gas phase. High resolution spectroscopic studies of methylated furan compounds are generally limited to pure rotational spectroscopy in the vibrational ground state. This lack of results might be explained by the difficulties arisen from the internal rotation of the methyl group inducing non-trivial patterns in the rotational spectra. In this study, we discuss the benefits to assign the mm-wave rotational-torsional spectra of methylfuran with the global approach of the BELGI-Cs code compared to local approaches such as XIAM and ERHAM. The global approach reproduces the observed rotational lines of 2-methylfuran and 3-methylfuran in the mm-wave region at the experimental accuracy for the ground vt=0 and the first torsional vt=1 states with a unique set of molecular parameters. In addition, the V3 and V6 parameters describing the internal rotation potential barrier may be determined with a high degree of accuracy with the global approach. Finally, a discussion with other heterocyclic compounds enables the study of the influence of the electronic environment on the hindered rotation of the methyl group.     

(Trifluoromethylselenyl)methylchalcogenyl as Emerging Fluorinated Groups: Synthesis under Photoredox Catalysis and Determination of the Lipophilicity

The synthesis of molecules bearing (trifluoromethylselenyl)methylchalcogenyl groups is described via an efficient two-step strategy based on a metal-free photoredox catalyzed decarboxylative trifluoromethylselenolation with good yields up to 88 %, which raised to 98 % in flow chemistry conditions. The flow methods allowed also to scale up the reaction. The mechanism of this key reaction was studied. The physicochemical characterization of these emerging groups was performed by determining their Hansch–Leo lipophilicity parameters with high values up to 2.24. This reaction was also extended to perfluoroalkylselenolation with yields up to 95 %. Finally, this method was successfully applied to the functionalization of relevant bioactive molecules such as tocopherol or estrone derivatives.     

Recent advances on the use of active anodes in environmental electrochemistry

Active anodes, especially those consisting of metal mixed oxides (MMOs) containing Ru and/or Ir oxides, have been applied in the treatment of wastewater, especially when chloride ions are present. Their characteristics continuously drive the study of applications of these materials, be they in the degradation of different organic molecules, the preparation of new electrode materials and in the association of various processes to increase pollutant removal. Thus, this brief review aims to present some of the recent advances in the application of active anode materials in environmental electrochemistry. Focussing on the 2018–2020 period, it is possible to note many applied studies, using commercially available materials, covering a wide range of target pollutants. Still other studies aim to modify the catalyst surfaces to increase the mineralization capacity, and the use of these anodes in the production of free chlorine species to mediate indirect organic reduction is observed.     

Sur les singularités des séries de fractions rationnelles

Rendiconti del Circolo Matematico di Palermo Series 1 -     

An expansion for the number of partitions of an integer

The Ramanujan Journal - We consider p(n) the number of partitions of a natural number n, starting from an expression derived by Báez-Duarte in (Adv Math 125(1):114–120, 1997) by relating...     

Monopoles, particles and rational functions

We prove a recent conjecture of Manton and Murray: if a polynomialp(z) of degreek — 1 is given, then anSU (2) monopole corresponding to a rational functionp(z)/q(z) with well-separated poles \₁,...,\_k is approximately made up from charge 1 monopoles located at points (1/2 In p(\_i), \_i). We show how the rate of approximation changes with the numeratorp(z) with the result that, as long as the values of the numerator remain close together relative to the distances between poles, the above statement remains true and ceases to be so otherwise.We also show that the spectral curve of the monopole approaches the union of curves of charge 1 monopoles exponentially fast. This remains true forSU (N) monopoles.