Template-dependent hydrophobicity in mesoporous organosilica films

A template dependence of the degree of self-hydrophobization of methylene-bridged periodic mesoporous organosilica (PMO) films is reported. The film with the smallest pore size of 1.7 nm, templated by CTAC, results in higher hydrophilicity when compared to films with a pore size of 4.1 or 5.3 nm, templated by BrijL4 and BrijS10, respectively. Both the surface and the bulk hydrophilicity were evaluated by water contact angle measurements and water ellipsometric porosimetry and the same trends were observed. Additionally, we provide the first evidence for a steric hindrance of the self-hydrophobization process. We show that a partial template removal results in the methylene-to-methyl transformation being observed at a temperature as low as 200 degrees C, significantly lower than previously demonstrated. These results should be taken into account when PMO materials are considered for applications such as low-k dielectrics, membranes, catalyst and chromatographic supports, and drug carriers

UV cure of oxycarbosilane low-k films

status: publishe

A Novel Ex Vivo Approach Based on Proteomics and Biomarkers to Evaluate the Effects of Chrysene, MEHP, and PBDE-47 on Loggerhead Sea Turtles (Caretta caretta)

The principal aim of the present study was to develop and apply novel ex vivo tests as an alternative to cell cultures able to evaluate the possible effects of emerging and legacy contaminants in Caretta caretta. To this end, we performed ex vivo experiments on non-invasively collected whole-blood and skin-biopsy slices treated with chrysene, MEHP, or PBDE-47. Blood samples were tested by oxidative stress (TAS), immune system (respiratory burst, lysozyme, and complement system), and genotoxicity (ENA assay) biomarkers, and genotoxic and immune system effects were observed. Skin slices were analyzed by applying a 2D-PAGE/MS proteomic approach, and specific contaminant signatures were delineated on the skin proteomic profile. These reflect biochemical effects induced by each treatment and allowed to identify glutathione S-transferase P, peptidyl-prolyl cis-trans isomerase A, mimecan, and protein S100-A6 as potential biomarkers of the health-threatening impact the texted toxicants have on C. caretta. Obtained results confirm the suitability of the ex vivo system and indicate the potential risk the loggerhead sea turtle is undergoing in the natural environment. In conclusion, this work proved the relevance that the applied ex vivo models may have in testing the toxicity of other compounds and mixtures and in biomarker discovery

Selective electroless deposition of cobalt using amino-terminated SAMs

© 2019 The Royal Society of Chemistry. The continuation of CMOS scaling leads to the necessity of replacing Cu as an interconnect material with a metal with lower resistivity and better reliability performance. At the same time, significant technological improvements are required to mitigate the pattern overlay requirements when forming multilevel structures with a half-pitch below 10 nm. Area-selective deposition (ASD) offers an elegant way to enable self-alignment of multilevel structures. However, defectivity is a typical bottleneck of ASD integration. This work explores the selective electroless deposition (ELD) of Co as a replacement of Cu as an interconnect metal. The selective metallization process is promoted by the selective placement of an amino-terminated organic layer in combination with confined grafting of a Pd catalyst. Co films thicker than 40 nm can be formed on amino-terminated surfaces, while the surfaces with no amino functionality remain completely free of Pd and Co according to EDS chemical analysis and SEM inspection. This article offers a detailed study of selective Co growth on blanket and patterned structures and investigation of the ELD Co film properties, such as low-temperature recrystallization at 420 °C, grain structure, chemical composition and segregation of impurities. It is demonstrated that the resistivity of the ELD Co films exhibits lower thickness dependence when compared to that of PVD Co, which can be attributed to the ELD Co grain size exceeding the Co film thickness. In addition, it is shown that the underlying organic layer prevents the silicidation of the annealed Co film on the Si substrate while promoting interface adhesion values as high as 8.2 J m -2 ± 0.7 J m -2 for a 50-nm thick Co film.status: publishe

Optical properties and colorimetric evaluation of resin cements formulated with thio-urethane oligomers

The aim of this study was to evaluate the color parameters and optical properties of resin cements (RCs) formulated with thio-urethanes (TUs). Six TUs were synthesized by combining thiols (pentaerythritol tetra-3-mercaptopropionate [PETMP] or trimethylol-tris-3-mercaptopropionate [TMP]) with di-functional isocyanates (1,6-Hexanediol-diissocyante [HDDI] [aliphatic-AL] or 1,3-bis(1-isocyanato-1-methylethyl) benzene [BDI] [aromatic-AR] or Dicyclohexylmethane 4,4 '-Diisocyanate [HMDI] [cyclic-CC]). TUs (20 wt%) were added to a BisGMA/UDMA/TEGDMA matrix. Filler was introduced at 60 wt%. Fluorescence was evaluated through an UV-light emitting equipment. Coordinates L*, a*, and b* were obtained in the black and white reflectance to evaluate the contrast ratio (CR) and translucency parameter (TP00). The coordinates obtained from transmittance were used to evaluate lightness (L*), chroma (C*), color difference (Delta E-00) after 6 month, and whiteness index for Dentistry (WID). RCs formulated with TUs presented significantly higher CR, and fluorescence (with T_AR). Significantly lower C*, L*, and TP00 (except for P_AR and T_AL) were also observed in RCs containing TUs. Delta E-00 were not significant among the materials. WID was not influenced. RCs composed by TU oligomers present higher CR and lower translucency. The material also present higher fluorescence depending on the oligomer used. The use of thio-urethanes to formulate resin cements can ensure a luting material with improved potential to mask colored substrates due to the higher contrast ratio and lower translucency obtained. A final higher fluorescence of restoration is also expected with the use of specific oligomer312153159FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2017-11913-8The authors thank NIH‐NIDCR (1R15‐DE023211‐01A1 and 1U01‐DE02756‐01) and FAPESP 2017‐11913‐8 for financial support. The donation of methacrylate monomers by Esstech is also greatly appreciate

Selective electroless deposition of cobalt using amino-terminated SAMs

The continuation of CMOS scaling leads to the necessity of replacing Cu as an interconnect material with a metal with lower resistivity and better reliability performance. At the same time, significant technological improvements are required to mitigate the pattern overlay requirements when forming multilevel structures with a half-pitch below 10 nm. Area-selective deposition (ASD) offers an elegant way to enable self-alignment of multilevel structures. However, defectivity is a typical bottleneck of ASD integration. This work explores the selective electroless deposition (ELD) of Co as a replacement of Cu as an interconnect metal. The selective metallization process is promoted by the selective placement of an amino-terminated organic layer in combination with confined grafting of a Pd catalyst. Co films thicker than 40 nm can be formed on amino-terminated surfaces, while the surfaces with no amino functionality remain completely free of Pd and Co according to EDS chemical analysis and SEM inspection. This article offers a detailed study of selective Co growth on blanket and patterned structures and investigation of the ELD Co film properties, such as low-temperature recrystallization at 420 degrees C, grain structure, chemical composition and segregation of impurities. It is demonstrated that the resistivity of the ELD Co films exhibits lower thickness dependence when compared to that of PVD Co, which can be attributed to the ELD Co grain size exceeding the Co film thickness. In addition, it is shown that the underlying organic layer prevents the silicidation of the annealed Co film on the Si substrate while promoting interface adhesion values as high as 8.2 J m(-2) +/- 0.7 J m(-2) for a 50-nm thick Co film

Surface Passivation of Polymer Based Redistribution Layers for Area Selective Deposition of an Oxygen Barrier

Heterogeneous 3D integration is being hailed as the driver for new technologies due to its stacked device architecture. This increases functionality as the number and length of interconnecting wires decreases, in turn decreasing power consumption. In these advanced packaging technologies, the metal redistribution layers (RDLs) and the insulating polymer surrounding them are crucial components on which stringent reliability requirements are placed. The metal RDL’s are necessary to reroute signals from device level to packaging level. The polymer insulator, used as an alternative to traditional dielectric materials, must (i) be photosensitive to be compatible with lithography processing steps, (ii) possess high mechanical strength, (iii) exhibit good electrical performance, (iv) have a high thermal stability and glass transition temperature, and crucially (v) it must not be hygroscopic. Low or no moisture uptake of the polymer is essential as any moisture can cause mechanical and electrical reliability issues. Absorbed moisture can cause oxidation of Cu lines leading to the well-known problem of Cu diffusion resulting in voids, contact issues, delamination, electromigration and higher leakage currents