Papers by Keyword: Ruthenium

Abstract: Wet chemicals for ruthenium (Ru) etching are required for the formation of reliable Ru interconnects in advanced semiconductor technology nodes. In the present study, a novel alkali wet etchant, referred to as TK-1, has been developed in order to overcome issues with conventional Ru etchants, such as a low etch rate and the formation of toxic RuO₄ gas. Regardless of the Ru deposition process, TK-1 exhibits a high Ru etching selectivity of greater than 100 relative to dielectric and liner materials. It also suppresses the production of RuO₄ during the etching process. TK-1 has potential applications for Ru recess etching during fully self-aligned via fabrication.

Abstract: Two different ruthenium content (0.5%, 1.0%) of WC - (W, Ti, Ta) C - Co cemented carbide were prepared by conventional cemented carbide production process. The results showed that adding ruthenium powder can improve the microstructure of alloy compared with excluding ruthenium carbide. The microstructure of alloy with ruthenium addition had uniform structure with less coarse grain.The addition of ruthenium could obviously promote the transverse rupture strength of WC - (W, Ti, Ta) C-Co cemented carbide, and when the adding amount was 1.0%, transverse rupture strength increased by 30%. The addition of ruthenium slightly increased the hardness of the alloy. The results of Scanning electron microscopy and spectrum analysis showed that ruthenium mainly existed in the bonding phase Co. The cutting test showed that the alloy with Ru had better wear resistance.

Abstract: Oxindole derivatives were efficiently synthesized from diazoamides derived from aniline derivatives in the presence of a Ru(II)-Pheox catalyst. Ru(II)-Pheox was found to be one of the most efficient catalysts so far for the synthesis of oxindole derivatives from the diazoamides in high yields (up to 99%) with high regioselectivity. Furthermore, the reaction was rapid and no substituent effects on the aromatic ring.

Abstract: The wet-chemical etching of ruthenium in acidic solutions of cerium (IV) has been investigated using electrochemical methods. Etch rates were determined using Rutherford backscattering spectroscopy (RBS) and post-etching surface roughness was investigated using atomic force microscopy (AFM). Low-k material is compatible with the etchant, however, residues were formed.

Abstract: A selection of anode coatings has been studied to get sodium hypochlorite in low concentrationduring the electrolysis of 3% solution of sodium salt and the Black Sea water. The corrosive resistance of anodes has been determined, with different batches of ruthenium and iridium oxides, as well as their characteristics: chlorine outlet while passing throughthe current, voltage on the cell, the dynamics of concentration growth of available chlorine in solution.

Abstract: Ruthenium is widely used as catalyst, magnetic recording and electrode materials. In this study, high-purity (≥99.995 wt%) ruthenium sponge was synthesized from crude ruthenium (≤99.9 wt%) by chemical refining technique. Initially, crude Ru was transformed into H₂RuCl₆ by distilling treatment. The H₂RuCl₆ was, then, added with NH4Cl powder to precipitate (NH₄)₂RuCl₆ powder. Afterward, the (NH₄)₂RuCl₆ powder was ignited in air and transformed into RuO₂. Finally, RuO₂ was changed to Ru by hydrogen reduction method. Impurities included in the starting Ru powder were eliminated after distillation and precipitation treatments. As-obtained ruthenium particles were spherical-like agglomeration, the average size was about 6 μm and the powder density was 11.83 g/cm³. The details of chemical transforming mechanisms in the refining process were described.

Abstract: This study aimed for the synthesis of 4-Aryl-2-amino-6-(4-hydroxy coumarin-3-yl) pyridine-3-carbonitriles derivatives 4, suitable for use as antibacterial, anti-oxidant and anti-inflammatory activities via a versatile, readily accessible 3-((2E)-3(aryl)prop-2-enoyl)-2H-chromen-2-one, 3, which was prepared by refluxing 3-acetyl-4-hydroxycoumarin with aromatic aldehydes in chloroform in the presence of a catalytic amount of piperidine. Then the direct reaction of the obtained chalcones 3 with malonitrile in the presence of ammonium acetate in one step gave products 4. Most of the new compound 4 exhibit moderate antibacterial activity against Gram Negative bacterial strains (E. coli, K. pneumonia, S. typhi and S. flexneri). In addition, the compounds 4 were investigated for anti-oxidant activities by super oxide radical, DPPH (2,2-Diphenyl-1-picrylhydrazyl), and hydroxyl radical scavenging assays, where most of the compounds displayed significant antioxidant activities. Furthermore, these 4-Aryl-2-amino-6-(4-hydroxy coumarin-3-yl) pyridine-3-carbonitriles 4 were evaluated for anti-inflammatory activity by indirect haemolytic and lipoxygenase inhibition assays where compounds revealed good activity. The preparation of novel metal-free phthalocyanines and metallophthalocyanine complexes 11 and 12 (MPcs, M = Co, Zn, Cu and Mn), with four peripheral 6-hydroxy-4-methylcoumarin and 6-hydroxycoumarin substituents, were also prepared by cyclotetramerization of compounds 7 and 10 with the corresponding metal salts (Zn(OAc)₂.2H₂O, Co(OAc)₂.4H₂O, CuCl, Mn(OAc)₂.4H₂O) as a template for macrocycle formation in 2-(N,N-dimethylamino)ethanol.The electronic spectra of these compounds exhibit a band of coumarin identity together with characteristic bands of the phthalocyanine core. The new compounds were screened for antibacterial activity. Most of them are active against E. coli and S. aureus. In addition, some novel 3-acetylcoumarin derivatives 17 were prepared in good yields. Their in vitro antioxidant activities were assayed by the quantitative 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity method. In this way, novel coumarin phtalonitriles derivatives 42-44 were synthesized.The synthesis of these coumarin phtalonitriles was resulting from a nucleophilic aromatic substitution reaction between 4-nitrophtalonitrile and coumarins derivatives. The complexing properties of the coumarin derivatives toward alkali metal, alkaline earth metal, some transition metals and some heavy metal cations have been investigated in acetonitrile by means of UV spectrophotometry absorption and conductivity methods. Thus, the stoichiometry of the complexes formed and their stability constants were determined. We report also in this book chapter a sequence of two ruthenium-catalyzed transformations, namely olefin cross metathesis with allylic chloride followed by elimination, which gives a straightforward access to terminal 1,3-dienes from natural products. The structures of all the new obtained compounds were confirmed by elemental analysis, IR, and multinuclear/multidimensional NMR spectroscopy (¹H, ¹³C-NMR, NOESY, HMBC) which allowed assignment of the complete network of proton and carbon atoms).

Abstract: Polyethylenimine (PEI)-coated biomass-chitosan composite fiber (PBCF) was fabricated to recover Ru from acetic acid waste solution. The present work aimed to understand the effects of molecular weight of chitosan and drying method on stability and sorption performance of the PBCF. For this, the PBCF was prepared by extruding the mixed solutions of chitosan and Corynebacterium glutamicum to form the composite fibers which were modified with ionic polymer, PEI. The degree of swelling of PBCFs prepared by hot-air, natural, and freeze drying methods were 1.25, 1.34, and 1.07 %, respectively, indicating that the freeze-drying method was the best. Batch biosorption studies showed that the maximum Ru uptake could be achieved with PBCF prepared with medium molecular weight chitosan, and could reach 34.1 mg/g, which was 7.9 times higher than that of the commercial ion exchange resin, LEWATIT^® MonoPlus M 500 (4.3 mg/g). Therefore, PBCF can be considered as an alternative sorbent to synthetic resin for recovery of Ru form industrial acetic acid waste solution.

Abstract: The effects of Al, Co, Re, and Ru on the stacking fault energy in Ni alloys were analyzed using computational thermodynamics. The effects of adding up to 5 at% Re or Ru to a Ni-15at%Co system were found to be weak at 300 °C, 700 °C, and 900 °C. However, Al addition decreased the stacking fault energy in a Ni-15at%Co-Xat%Ru system, where X = 0, 3, 5. In addition, this decrease in the stacking fault energy due to Al addition became more significant as the amount of Ru increased. Furthermore, in Ni–Co–Al–Ru alloys containing 9at%Al, the addition of 5at%Ru decreased the stacking fault energy as much as the addition of 12.5at%Co at 900 °C. The effects of Co and Ru addition on the γ/γ’ microstructure of Ni-based superalloys were also discussed.

Abstract: A novel Ru thin film formation method was proposed to deposit metallic Ru thin films on TiN substrate for future backend of line process in semiconductor technologies. RuO₂ thin films were first grown on TiN substrate by oxygen plasma-enhanced atomic layer deposition technique. The deposited RuO₂ thin films were then reduced into metallic Ru thin films by H₂/N₂-assisted annealing.