Multilayer diffraction gratings are designed to improve the detection limit and sensitivity of soft x-ray flat-field spectrographs in the region of 300–1000 eV, placing emphasis on Fe-L (705 eV), Cu-L (930 eV), and Zn-L (1012 eV) emissions. For this purpose, spectral flux was used as the performance index, which is proportional to the amount of optical flux incident into a detector and correlated with detection sensitivity. A super-mirror-type W/B4C multilayer coating [Koike et al., Rev.Sci. Instrum. 94, 045109 (2023)] was employed to improve diffraction efficiency in a wide energy region. The unique feature of the multilayer structure is that the average refractive index and the period length of W/B4C layer pairs are increased from the bottom to top layers. In addition, the incidence angle was reduced to 86.03° from 88.65° and the nominal groove density was increased to 3200 lines/mm from 2400 lines/mm of our previous design, to improve spectral flux while maintaining dispersion and spectral resolution. A holographic varied-line-spacing spherical grating and a soft x-ray flat-field spectrograph were designed, using the aspherical-wavefront-recording method, assuming the nominal grating constant and incident angle described above. The numerical simulation results showed that the spectrograph employing the newly designed grating with the W/B4C multilayer indicated 3.2–8.2 times higher spectral flux compared with those using the previously designed grating while keeping the same spectral resolution.

A soft x-ray varied-line-spacing (VLS) laminar-type spherical grating with a super-mirror-type (SMT) multilayer was designed for a soft x-ray high resolution flat-field spectrograph in a region of 2–4 keV. The effective groove density of the designed VLS grating is 3200 lines/mm, and the local groove density varies from 2700 to 3866 lines/mm. The geometrical imaging property was evaluated by numerical calculations. The resolving power estimated by means of ray tracing was up to ∼103. For the evaluation of diffraction efficiency, the SMT multilayer structure designed for 3200 lines/mm in our previous work, Koike et al., Rev. Sci. Instrum. 94, 045109 (2023), was employed, and the numerical calculation was performed considering the local groove density of VLS grooves and the local incidence angle being affected by the curvature of the spherical surface and the geometrical relation between the source and incidence point on the grating. The results showed that the SMT multilayer-coated grating exhibited about an order of magnitude higher diffraction efficiency compared with an Au-coated grating.

An objective soft x-ray flat-field spectrograph employing a laminar-type bilayer coated, varied-line-spacing, spherical grating was designed to improve the detection limit and sensitivity of soft x-ray flat-field spectrographs in a region of 250-550 eV. As a design criterion, spectral flux, SF, [Hatano et al., Appl. Opt. 60, 4993-4999 (2021)], which is proportional to the amount of optical flux incident onto a detector and correlated with detection sensitivity, was used to be maximized. To enhance reflectivity with the coating design, Au/Ni bilayer coating was investigated to optimize the incidence angle and thickness of the Ni layer. This is based on the consideration that, in an energy region of over 400 eV, refractive indices of Au (bottom layer), Ni (top layer), and vacuum are increased from the bottom to the top of the layers, and a supplemental enhancement of reflectivity can be expected by optimizing the thickness of the top layer. Thus, the thickness of Ni and the incidence angle were chosen to be 8.0 nm and 86.00 degrees, respectively. To maintain dispersion and spectral resolution of the grating used at an incidence angle of 87.07 degrees as previously designed, groove density was increased to 1500 lines/mm from 1200 lines/mm of our previous design. Finally, a holographic, varied-line-spacing, spherical grating was designed assuming an aspherical-wavefront-recording configuration. The numerical simulation results showed that the spectrograph employing newly designed grating with laminar-type grooves and Au/Ni bilayer coating exhibited 2-18 times higher spectral flux as well as an improved spectral resolution compared with those obtained with the previously designed gratings and spectrographs.

Soft x-ray diffraction gratings coated with a supermirror-type multilayer were designed to enhance diffraction efficiency in the energy range of 2-4 keV by means of numerical calculations. The optimized groove depth and incidence angle are 2.05 nm and 88.65°, respectively, for the grating having a groove density of 3200 grooves/mm. Regarding the multilayer structure, the optimum number of B4C/W layers pair was 11 and the thickness of B4C was increased from bottom to top, while that of W was kept constant. The replacement of the top layer of W by either Co, Cr, or Ni was an effective means of obtaining uniform diffraction efficiency. In the region of 2-4 keV, the calculated diffraction efficiency of the designed gratings was up to ∼5.3%, on average, and almost eight times larger than that of ∼0.7% of an Au coated grating.

Laminar-type spherical diffraction gratings overcoated with carbon-based materials were designed, fabricated, and evaluated for the purpose of enhancing the analytical sensitivity of the flat-field spectrograph in a vacuum ultraviolet region of 35–110 eV. As the design benchmark for numerical calculations, diffraction efficiency (DE) and spectral flux, which are defined by the product of the DE and numerical aperture and correlate with the analytical sensitivity of the spectrograph, were used. To simplify the feasibility study on the overcoating effects, we assumed a laminar-type grating having a grating constant of 1/1000 mm and coated with a Au layer of 30.0 nm thickness and an incidence angle of 84.0°. The optimized groove depth and duty ratio were 30.0 nm and 0.3, respectively. In addition, the optimum thicknesses of the overcoating layer were 44, 46, 24, and 30 nm for B4C, C, diamond-like-carbon, and SiC, respectively. Based on these results, we have fabricated a varied-line-spacing holographic grating overcoated with B4C with a thickness of 47 nm. For the experimental evaluation, we used the light source of Mg-L and Al-L emissions excited by the electron beam generated from an electron microscope, an objective flat-field spectrograph, and a CCD imaging detector. The experimental results showed that the spectrograph employing a new grating overcoated with the B4C layer indicated almost the same spectral resolution and 2.9–4.2 times higher analytical sensitivity compared with those obtained with a previously designed Au-coated grating having a grating constant of 1/1200 mm and used at an incidence of 86.0°.

A grazing incidence condenser is developed for objectives with large numerical aperture working in Carbon-window wavelength region (λ=4.4-5.0  nm) with the use of a point light source. The condenser is composed of four pieces of toroidal mirrors and a piece of the mirror was fabricated to evaluate the performance of the mirror. The radii of the toroidal mirror are determined by ray-trace calculation, and each radius of the mirror substrate and the roughness of the polished surface were evaluated to satisfy the designed parameter. A Co/C reflection multilayer is also designed to reflect soft x-ray light at 4.5 nm wavelength, and the reflection multilayer was deposited on the mirror surface. Measured reflectance of the toroidal mirror with the reflection multilayer is higher than 0.32 at 4.5 nm wavelength.

For accurate reflection phase manipulation of spherical multilayer mirrors used in extreme ultraviolet (EUV) imaging, a wide-area ion beam with a homogenized radial distribution was produced for period-by-period ion milling. Measured variations of the milling depth with incident angle showed that Si and Mo have the same angular dependence within the effective aperture used in our imaging optics. By using the designed homogenizer mask, the ion-milling depth was successfully homogenized to within an error of +/- 1.9% over a 50-mm-wide concave mirror. Furthermore, a versatile homogenizer mask with adjustable opening angle plates was developed. With this mask, an ion-milling depth-profile homogeneity of +/- 1.7% was realized. Although a slight decrease in the peak EUV reflectance was measured as the incident angle decreased, the effectiveness and practicality of our correction method has been demonstrated.

The whole profile of the specular X-ray reflectivity curve was simultaneously and quickly measured with no need to rotate the specimen, the detector or the monochromator crystal. A white synchrotron beam from a bending magnet source is incident on a bent-twisted silicon (111) crystal polychromator that produces a convergent X-ray beam with a continuously varying wavelength (energy) and glancing angle to the specimen surface. This convergent X-ray beam was specularly reflected in the vertical direction by the specimen placed at the focus. The normalized spatial distribution across the beam direction of the reflected beam represents a specular X-ray reflectivity curve because each position along the line recorded on the two dimensional detector surface corresponds to a different momentum transfer. Reflectivity curves from a (001) silicon wafer, a nickel thin film on a silicon substrate, and a water surface were measured with data collection times of 0.001-100 s, 0.01-100 s, and 1.0-1000 s, respectively. The simultaneously covered momentum transfer range was 0.03-0.52 angstrom(-1) for solid specimens and 0-0.41 angstrom(-1) for liquid specimen.

For accurate nm‐figure error correction of EUV multilayer mirror optics, a three‐dimensionally controlled ion milling method was developed. To demonstrate the reflection phase manipulation of an EUV multilayer, 10 periods of a 40‐period Mo/Si multilayer were partially removed. A partially milled Mo/Si multilayer with a contact double slit was successfully fabricated for interference fringe observations, which were carried out using a Young’s EUV interferometer with a reflection configuration. The fringe pattern revealed a small reflection phase change after multilayer surface milling. EUV interferometry results demonstrated the effectiveness of the proposed method for sub‐nanometer digital wavefront error correction in the case of multilayer mirror optics used in diffraction‐limited imaging.

A Mo single-layer film with a stepwise thickness distribution was fabricated on the same Mo/Si reflection multilayer film. Total electron-yield X-ray standing-wave (TEY-XSW) spectra of the aperiodic multilayer were measured with reflection spectra. The peak positions of the standing waves in the TEY-XSW spectra changed as the film thickness of the top Mo-layer increased.

For rejection of unwanted background component in the reflection spectrum of EUV multilayer mirrors, thin film transmission filters of Mo, Zr, and Be were evaluated with a laser produced plasma EUV source and an imaging plate detector. It is found that in addition to a standard Zr filter, a Mo filter has good rejection characteristics. In particular, for multilayer mirror use at a large angle of incidence such as the polarizing angles around 45°, Mo shows better rejection characteristics than Zr. It is also confirmed that Be transmits non-ignorable amount of UV background.

All layer thicknesses of a 40 periods EUV multilayer composed of Mo and Si with a designed period thickness of 6.918nm were measured by our in situ ellipsometry. The period thickness of Mo/Si multilayer was obtained to be 7.07nm in average. This coincides well with period thicknesses of 7.078 and 7.081nm as determined respectively by EUV reflectometry and X-ray diffractometry after fabrication. The difference of 0.01nm, which is as to be 0.14%, is sufficiently small for precise period thickness control of EUV multilayer fabrication.

Faraday rotation spectra of Co/Pt multilayers were obtained in the region including Co M-2,M-3 and Pt N-6,N-7 absorption edges by using multilayer polarizers, and were transformed to magnetic circular dichroism (MCD) spectra by Kramers-Kronig analysis (KKA). From the dependence of the rotation angle on the layer thickness, it was suggested that the magnetization of Co tends to be uniform in Co layers and that of Pt is localized at Co/Pt interfaces. The orbital magnetic moment of Co was estimated to be about 0. 17 (mu Beta)/Co. The similarity of electronic states around magnetized Pt site between Co/Pt multilayers and CoPt3 alloy is suggested by the resemblance of the MCD spectra of both materials around Pt N-6,N-7 edges. In addition, magnetic Kerr rotation of Co/Cu multilayer was measured and was observed around Co M-2,M-3 and CU M-2,M-3 absorption edges. (c) 2005 Elsevier B.V. All rights reserved.

It was found that DNAs can act as attractive templates for oxidative polymerization of pyrrole and result in novel higher-order superstructures composed of the DNA padding and the conjugate polymer outer layer. Furthermore, the resultant DNA/poly(pyrrole) composite can be deposited on an ITO electrode. The TEM and SEM observations have shown that oxidative polymerization creates a variety of superstructural poly(pyrrole) assemblies such as nanosized rodlike, circular, or supercoiled structures, reflecting the higher-order conformations of DNAs acting as the templates. The findings establish that the morphology of the conjugate polymer assemblies are controllable by a change in the DNA morphology used as their templates. The deposition of DNAs onto the ITO electrode was characterized by (1) ATR IR absorption bands assignable to DNA, (2) XPS binding energy of the phosphate group assignable to DNAs, and (3) binding of ethidium bromide (EB) to DNAs as detected by UV-vis spectroscopy and confocal laser scanning microscope (CLSM). The further detailed examination of the SEM pictures has established that the composite consists of a fibrous structure or its bundled structure, depending on the polymerization conditions. Interestingly, the ITO electrode modified by the DNA/poly(pyrrole) composite showed the CV responsiveness to DNA interealators, indicating a potential to apply this system to a new amperometric DNA-based sensor.

DNA which binds monocationic [60]fullerene (1) and tetracationic porphyrin (TMPyP) was readily fabricated by electrochemical oxidative polymerization of 3.4-ethylenedioxythiophene (EDOT) and the resultant poly(EDOT) composite was deposited on an ITO electrode as a stable thin film. Spectral and CV analyses established that one 1 and one TMPyP are bound per 57 nucleobase units, that is, every three pitches of DNA. Photoirradiation of this 1/TMPyP/DNA-poly(EDOT) film generated a photocurrent in 3.8% quantum yield, which was much higher than those obtained from 1/DNA and TMPyP/DNA systems. One can conclude, therefore that the photoexcited energy of TMPyP is transferred to 1, which is collected by the electron-conducting poly(EDOT) film. The present paper shows that DNA is useful as a scaffold to arrange redox-active couples in a one-dimensional matrix.

Angewandte Chemie International EditionVolume 43, Issue 4 p. 465-469 Communication Helical Superstructure of Conductive Polymers as Created by Electrochemical Polymerization by Using Synthetic Lipid Assemblies as a Template† Tsukasa Hatano, Tsukasa Hatano Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this authorAh-Hyun Bae, Ah-Hyun Bae Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this authorMasayuki Takeuchi Dr., Masayuki Takeuchi Dr. Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this authorNorifumi Fujita Dr., Norifumi Fujita Dr. Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this authorKenji Kaneko Prof. Dr., Kenji Kaneko Prof. Dr. HVEM Laboratory, Kyushu University, Fukuoka 812-8581, JapanSearch for more papers by this authorHirotaka Ihara Prof. Dr., Hirotaka Ihara Prof. Dr. Department of Materials and Life Science, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860–8555, JapanSearch for more papers by this authorMakoto Takafuji Dr., Makoto Takafuji Dr. Department of Materials and Life Science, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860–8555, JapanSearch for more papers by this authorSeiji Shinkai Prof. Dr., Seiji Shinkai Prof. Dr. seijitcm@mbox.nc.kyushu-u.ac.jp Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this author Tsukasa Hatano, Tsukasa Hatano Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this authorAh-Hyun Bae, Ah-Hyun Bae Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this authorMasayuki Takeuchi Dr., Masayuki Takeuchi Dr. Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this authorNorifumi Fujita Dr., Norifumi Fujita Dr. Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this authorKenji Kaneko Prof. Dr., Kenji Kaneko Prof. Dr. HVEM Laboratory, Kyushu University, Fukuoka 812-8581, JapanSearch for more papers by this authorHirotaka Ihara Prof. Dr., Hirotaka Ihara Prof. Dr. Department of Materials and Life Science, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860–8555, JapanSearch for more papers by this authorMakoto Takafuji Dr., Makoto Takafuji Dr. Department of Materials and Life Science, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860–8555, JapanSearch for more papers by this authorSeiji Shinkai Prof. Dr., Seiji Shinkai Prof. Dr. seijitcm@mbox.nc.kyushu-u.ac.jp Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan, Fax: (+81) 092-642-3611Search for more papers by this author First published: 14 January 2004 https://doi.org/10.1002/anie.200351749Citations: 83 † We would like to thank the referees for their fruitful comments on our manuscript. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract A templating method is used to create conductive polymers that have a helical superstructure. The driving force is an electrostatic interaction between the negative charge in a synthetic lipid and the cationic charge generated in the polymers during oxidative electrochemical polymerization of ethylenedioxythiophene (EDOT) and a pyrrole (see picture; CV=cyclic voltammetry). Citing Literature Supporting Information Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2004/z51749_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume43, Issue4January 16, 2004Pages 465-469 RelatedInformation

For the purpose of fabricating curved multilayer mirrors, we developed an ion beam sputtering deposition system with a programmable shutter for thickness distribution control. In this report we fabricated a Mo/Si multilayer concave mirror of a 100 mm diameter and a 300 mm radius of curvature to be used at 13.5 nm at an angle of incidence of 5°. At first a test multilayer was deposited without thickness distribution control and the lateral distribution of deposition rate was evaluated. We used the normal incidence EUV reflectometry to determine the multilayer period thickness while we usually use the small angle X‐ray diffractometry when the substrate is plane. The measurements were performed at BL‐12A of the Photon Factory, KEK. In an analysis of a spectral reflectance, the side band structure as well as the main peak was taken into account. The natural thickness at the outermost part was found to be 13% thinner than that at the center. Next a Mo/Si multilayer of uniform thickness over the substrate was d...

We have adopted our new ellipsometer of picometer‐thickness sensitivity for sputtering rate monitoring of extreme ultraviolet (EUV) multilayer fabrication. With real time thickness analysis during Mo/Si multilayer fabrication, the sputtering rates of Mo and Si were observed to be 0.9162nm/min and 4.752nm/min, respectively. EUV reflectance of this multilayer mirror was measured at the Photon Factory KEK and the period thickness was found to be 7.22nm. This period thickness is compared with an ellipsometric value of 6.98nm calculated by the final total thickness divided by the number of periods of 40. The difference of 3.3% can be attributed by a compound layer formation at every boundary of Mo and Si as observe by ellipsometry. The results proved good possibility of a single wavelength in‐situ null ellipsometry for accurate and detailed controlling of the period thickness of EUV multilayer.

The use of organogelators to template chiral and achiral polyaniline superstructures via the electrostatic interaction between anionic sulfonated polyaniline and a cationic gelator is described.

It was found that plasmid DNA can act as an attractive template for oxidative polymerization of pyrrole and result in the novel higher-order superstructures composed of the conductive polymers. The TEM and SEM observation estabilished that poly(pyrrole) grows up to nanosized rod-like, circular, and Supercoiled structures reflecting the higher-order conformation of plasmid DNA. The obtained polymer structures are drastically changed reflecting the controlled DNA morphologies used as their templates.