Dissociative excitation processes of HCOOH in the vacuum ultraviolet (VUV) region were studied by single-VUV photon with synchrotron radiation source and by two-ultraviolet (UV) photon with KrF excimer laser. In the VUV dissociation, fluorescence excitation cross sections for the OH(A) and HCOO* were separately determined in the 106–155 nm region. The branching fraction was found to be a function of the VUV excitation wavelength. The magnitude is σOH(A)/[σOH(A)+σHCOO*]=0.13 at 124.5 nm and gradually increases to 0.39 at 110 nm. In the UV multiphoton dissociation at 249 nm, OH(A) and HCOO* fragments were also identified by a fluorescence spectrum. The production of OH(A) was shown to take place in the two-UV photon absorption of HCOOH. Nascent rotational and vibrational (V/R) state distributions of OH(A 2Σ+) produced via the photodissociation at a single excitation energy of 9.96 eV (124.5×1/249 nm×2), HCOOH+nhν(n=1,2)→HCO+OH(A 2Σ+), were determined by simulation analysis of the dispersed fluorescence spectra. The internal state distributions were found to be of the relaxed type, and rotational distribution could be approximated by a Boltzmann distribution. One-VUV photon excitation gave the best-fit rotational temperature Tr(v′=0)=3000 K and vibrational population ratio Nv′=1/Nv′=0=0.14, while two-UV photon excitation showed Tr(v′=0)=2000 K with Nv′=1/Nv′=0=0.12. Possible mechanisms for the OH(A) formation by both excitation sources were examined based on simple theoretical models. The degree of internal excitation is not consistent with a direct dissociation on a repulsive surface, and neither is a dissociation from a long-lived intermediate state. The formation of OH(A 2Σ+) is interpreted as dissociation of an electronically excited intermediate state, leading to the formation of OH(A)+CHO, populated competitively via an electronic predissociation process. The substantially different V/R distributions observed are dependent on the excited precursor state initially accessed, and may result from the constraint in the competing predissociation step that follows.

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Highly insulating tantalum pentoxide (Ta2O5) capacitor films were obtained by dry O3 annealing at low temperatures ranging from 350 to 500 °C. Typical leakage current density and resistivity of a 10-nm-thick Ta2O5 film measured at 2 MV/cm were 2.5×10−8 A/cm2 and 4.8×1013 Ω cm, respectively, obtained by dry O3 annealing at 450 °C, while leakage current density of the as-deposited film was about 10−1 A/cm2. It was confirmed that the mechanism which improves the insulating properties after dry O3 annealing involves the reduction of the leakage current due to the reduction of the concentration of such impurities as hydrogen and carbon, and the reduction of oxygen vacancies in Ta2O5 films. In addition, amorphous Ta2O5 films annealed in dry O3 show much better insulating properties than polycrystalline films. This can be attributed to the suppression of leakage current at the grain boundaries. Regarding dielectric properties, Ta2O5 films have an average dielectric constant of 28, and the typical SiO2 equivalent thickness of a 10-nm-thick Ta2O5 film was 2.4 nm. Results of the time dependent dielectric breakdown measurement, the calculation of the storage node height of a capacitor, and the frequency dependence of the capacitance value suggest that the above Ta2O5 film is applicable to an integrated capacitor for next generation devices, replacing conventional capacitor films.

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This letter reports on highly insulating amorphous-Ta2O5 (a-Ta2O5) films with ultrathin SiO2 effective thickness [teff(SiO2)]. Insulating properties were improved using dry-O3 annealing at 450 °C, in which the typical leakage current density and resistivity at 1.5 MV/cm were 3×10−8 A/cm2 and 5×1013 Ω cm, respectively. Typical teff(SiO2) of 1.2 nm was obtained for the a-Ta2O5 film formed on a Ru/TiN/Ti/n+-Si substrate, where a Ru layer can act as an effective barrier against oxidation as well as interdiffusion during annealing. In contrast, the teff(SiO2) of the Ta2O5 film prepared on a conventional TiN/Ti/n+-Si substrate was increased by interfacial degradation. Technology employing Ru bottom electrodes and dry-O3 annealing will open a new era of logic embedded memory for 1 Gbit generation.

Dissociative excitation of CH 3 COCN to produce CN͑B-X͒ and CN͑A-X͒ fluorescence was studied by resonance enhanced multiphoton excitation at 292 nm. The laser power dependence of the CN͑B-X͒ fluorescence intensity and the lifetime of the one-photon excited S 1 state showed that CN͑B͒ formation takes place in the direct two-photon and two-body dissociation mechanism, CH 3 COCNϩ2h →CH 3 CO(X )ϩCN(B). Vibrational and rotational energy distributions of the nascent CN͑B͒ fragment were determined by a simulation analysis of the dispersed fluorescence spectrum. The vibrational distribution was found to be of the relaxed type and rotational distribution in each vibrational state could be approximated by a Boltzmann distribution. The best-fit vibrational distribution of CN͑B͒ was N v Ј ϭ0 : N v Ј ϭ1 :N v Ј ϭ2 ϭ1.00: 0.25: 0.07 with the respective rotational temperatures of T r (vЈϭ0)ϭ2600 K, T r (vЈϭ1)ϭ1000 K, and T r (vЈϭ2)ϭ900 K. The internal state distributions were found to be hotter than those predicted by the statistical model with complete energy randomization within the excited molecule. The results indicate a dissociation mechanism where both the vibrational energy deposition in the photoexcitation and available energy redistribution before the bond breakage are limited within the modes of the skeletal CCOCN structure. Possible decay channels other than the CN͑B͒ production, upon two-photon excitation at 292 nm, are also discussed based on the potential surfaces previously predicted. The formation of CN͑A͒ presently observed in the direct two-photon excitation can be interpreted as the dissociation of the electronic excited intermediate states, populated competitively via internal conversion͑s͒ from the upper electronic states. To obtain a deeper understanding of higher excited states of acetyl cyanide, the vacuum UV absorption cross section was also determined in the 110-200 nm region, using a synchrotron radiation source.

At the aperture of an optical fiber coupled with a SNOM SERRS-active Ag nanoparticles were selectively fabricated in a mixture of AgNO(3) and sodium citrate aqueous solution by photo-reduction due to an evanescent field.

A 47-year-old man was referred to our hospital with a 1-month history of fever and dyspnea after inhalation of insecticide in a confined space. We diagnosed rapidly progressive interstitial pneumonia. High-dose methylprednisolone, tacrolimus, and intermittent infusion of cyclophosphamide were administered. His condition rapidly deteriorated; therefore, extracorporeal membrane oxygenation therapy was performed. Unfortunately, he died 69 days after admission. Although typical skin findings suggestive of dermatomyositis were absent, anti-melanoma differentiation-associate gene (anti-MDA5) antibody was positive. Our findings suggest that in patients with hyperferritinemia and rapidly progressive interstitial lung disease (RP-ILD) demonstrating random ground glass shadows and peripheral consolidations by high-resolution computed tomography (HRCT) even if skin manifestations related to dermatomyositis are not complicated, we should assume anti-MDA5 antibody-positive interstitial pneumonia.