This paper describes a novel scatterometry-based optical inspection technique to quantify the degree of ordering of line/space gratings fabricated through a chemo-epitaxy directed self-assembly process. Process window analysis with this optical metrology is compared to analysis based on SEM and excellent agreement is demonstrated. However, other process parameters, including pattern CD, profile and especially pattern height influence the output signal. This requires normalization to a known good condition for correct data interpretation. The optical technique is useful for evaluating performance of closely related processes, and is thus ideally suited for bake optimizations, material selections, and monitoring purposes.

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In order to study the filterability of block copolymer solutions (BCP) with 2 nm to 20 nm rated lithography process filters, the determination of hydrodynamic diameter by dynamic light scattering (DLS), block copolymer concentration determination using UV-Vis spectroscopy and molecular weight distribution measurement using gel permeation chromatography (GPC) were conducted. Hydrodynamic diameters by DLS were sufficiently small and this indicates filtration is feasible. And consistency of BCP concentration by UV-Vis spectroscopy and molecular weight distribution by GPC confirmed that HDPE 5, 2 nm rated filters and Nylon 6,6 20, 10 nm rated filters provided desired filtration without sacrificing critical performance of BCP solution. Based on the results, these filters are recommended for defect reduction in DSAL process which provides 1X nm patterns.

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Polyion complex (PIC) micelles are expected to be used as nanocarrier for drug delivery. The PIC micelles formed by cationic anti-cancer drug, doxorubicin (DOX) and poly(ethylene glycol)-block-poly(4-vinylbenzylphosphonate) (PEG-b-PVBP) (DOX@PNP) was prepared with different pH conditions and composition ratio of the mixture. DOX and PEG-b-PVBP were spontaneously self-assembled in aqueous solutions into nanoparticles with average size of 45-55 nm over the entire range of the compositions of the mixtures including stoichiometric electroneutral complexes. The DOX@PNP described here would be promising nanocarrier for anti-cancer drug delivery.

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We have recently developed protein encapsulated nanoparticle that can be photocleaved with ultraviolet (UV) light. Biological activities of protein restricted by nanoparticle encapsulation were recovered by applying external light to the nanoparticle. We succeeded in control the cell function and fate by changing the local protein activity within cell using the protein encapsulated nanoparticle and focusing light. The positively charged nanoparticles were internalized within cell by means of the cellular uptake mechanism.

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All-polymer solar cells are expected as one of next generation photovoltaics. This paper presents two kinds of polymer/polymer blend solar cells to exemplify the potential advantages compared with conventional organic solar cells. The large difference in the HOMO/LUMO levels of donor/acceptor polymers results in a high voltage, and the large absorptivity up to near-infrared wavelengths allows to increase the photocurrent density. These characteristics are brought by development of a variety of low bandgap polymers. For the further improvement of conversion efficiency, it is a crucial issue to control the phase-separation structure on a nanometer scale.

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New thiadiazole-containing π-conjugated polymers have been successfully synthesized by the Stille coupling reaction of 2,5-bis(5’-bromo-3’,4’-dihexylthien-2’-yl)-1,3,4-thiadiazole (1) with various distannyl compounds as acceptor and donor monomer units, respectively. Most of polymers showed lower highest occupied molecular orbital (HOMO) energy level than poly(3-hexylthiophene) (P3HT). It was found that the bulky side chains of donor units tend to prevent the arrangements of main chains. The polymer comprised of thienothiophene donor units without side chains displayed relatively high solar cell performance with a power conversion efficiency (PCE) of 2.8% under the illumination of AM 1.5, 100 mW/cm².

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The single particle nanofabrication technique (SPNT) provides a facile and universal method to afford homogeneous, stiff, and semiconducting nanowires composed of fullerene derivatives. Following our previous success in methanofullerene (PCBM) nanowires hybridized with bulk heterojunction organic photovoltaics (OPV) of poly(3-hexylthiophene) (P3HT) and PCBM, we extended the research to indene C60 bis-adduct (ICBA). The power conversion efficiency of P3HT:ICBA OPV incorporating optimized length of ICBA nanowires was improved from 2.36% to 2.92%, alongside the increase of short circuit current density. We also discuss the interaction between substrate and unexposed fullerenes by examining immersing time to isolate such a short (50 nm) and thin (11 nm in radius) ICBA nanowire.

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Laser sintering of Au nanoparticles on a Cu substrate was studied toward an alternative to gold plating. The laser sintering by laser direct writing method required much higher laser power density in comparison with that on a glass substrate. The laser-induced heat accumulation method is proposed as a new laser sintering method which can be applied to a metal substrate with a high thermal diffusion coefficient such as a Cu substrate. In the sintering process, the dissipation through the Cu with a high thermal diffusion coefficient was reduced by using a thermally isolated Cu substrate, where the heat accumulation in the Cu micropattern was caused sintering of whole area by laser pulse irradiation at a small spot without laser beam scanning. The SIMS profile showed that the diffusion of the Cu atom through the gold layer was reduced remarkably by the laser sintering compared to the conventional heat treatment. The reduction of Cu diffusion into gold layer is due to the extremely short sintering time of the laser-induced heat accumulation method.

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Langmuir-Blodgett (LB) film of tetra-t-butyl-Zn-phthalocyanine (Pc), dicitratodiperoxotitanate complex (TAS) and ditetradecylviologen (V) triad was fabricated on thin glass waveguide as a cascade electron transfer model. The arrangement of the layer as Pc-TAS-V was successfully controlled by LB process. Monolayer of Pc or V was stabilized with TAS layer due to a multiple electrostatic interaction at air-water interface. Photoinduced electron transfer from the Pc to V through the TAS layer in Pc-TAS-V triad system was measured directly using waveguide spectroscopy. Electron transfer in the opposite layering sequence, V-TAS-Pc, was negligible. According to these results, direction of the electron transfer can be controlled in the triad by controlling the layering sequence using the hybrid LB procedure.

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The new low-band gap copolymers containing electron-accepting thienoisoindigo (TIDG) exhibit the low-lying lowest unoccupied molecular orbital (LUMO) at -3.8 eV. This envisions their use as n-type polymer in combination with typical p-type regioregular poly(3-hexylthiophene) (P3HT) towards all-polymer organic photovoltaics (OPV). The alternating fluorene and TIDG copolymer, PFTIDG, shows the electronic absorption maximum at 744 nm in the film states, of which spectrum is complementary to that of P3HT and thus advantageous for covering the wide solar spectrum. The laser and Xe-flash time-resolved microwave conductivity (TRMC) evaluations were performed for screening the effects of p/n blend ratio and thermal annealing in bulk heterojunction framework. The power conversion efficiency of 0.06% was obtained for pre-annealed P3HT:PFTIDG = 1:1 together with a high open circuit voltage of 0.92 V, which is suggestive of ambipolar characteristics of PFTIDG.

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Today ArF immersion processes are widely applied for advanced device manufacturing. ArF immersion lithography enables 4x nm half-pitch (hp) lithography. The use of double patterning extends immersion to 2x nm hp lithography. New materials for such 193nm lithography extensions are widely needed, especially for post-193nm immersion lithography technology. In this paper, we report a slimming material that makes line patterns smaller and it succeeds in forming 20nm lines.
In another study, we examined a new hydrophilic lactone to improve line width roughness (LWR) and defectivity. First, we studied the lactone reactivity with developer and its behavior during development. Then we verified its line width LWR performance and defectivity. When the hydrophilic new lactone is used in a photoresist, an improvement in LWR and defectivity photoresist was observed. This is very useful progress, especially in combination with processes such as multiple patterning to extend ArF immersion to sub-20nm hp dimensions.

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Hard masks play an important role in pattern transfer to the desired substrate in the semiconductor lithography processes. Organic and inorganic type hard masks are used. While most organic hard masks such as carbon and siloxane type are solution spin coated, inorganic type hard masks such as SiON and SiN are either chemical vapor deposited (CVD) or atomic layer deposited (ALD). Future generation of lithography processes require hard masks with higher resistance to fluorinated plasma and materials that can be easily wet stripped after pattern transfer process to prevent dry etch damage to the substrate underneath.
The present paper describes formation and functional properties of novel metal oxide hard masks by simple solution spin coating process. These novel metal oxide hard masks offer good etch selectivity and can easily be partially or fully wet strippable using commonly used chemicals in the FABs. The spin coatable composition has good long-term shelf life and pot life stability based on solution LPC analysis and wafer defect studies. The hard mask material absorbs DUV wavelengths and can be used as a spin-on inorganic or hybrid antireflective coating to control substrate reflectivity under DUV exposure of photoresist. At the same time they are transparent at 500-700nm for alignment mark identification and can be spin coatable up to 450nm thickness with good film quality. Some of these metal-containing materials can be used as an underlayer in EUV lithography to significantly enhance sensitivity of the photoresist. Specific metal hard masks are also developed for via or trench filling applications in IRT processes. The materials have shown good coating and lithography performance with a film thicknesses as low as 10 nm under ArF dry or immersion conditions.

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High-molecular-weight and functional acrylic block copolymers containing both the reactive and polar repeating units were synthesized using organotellurium-mediated living radical polymerization (TERP) technique. The block copolymers consisted of poly(tert-butyl acrylate) as the reactive segment and the random copolymer sequence containing n-butyl, 2-ethylhexyl, and 2-hydroxyethyl acrylate repeating units as the adhesive segment. The block copolymers exhibited high performance for the dismantlable adhesion responsible to dual external stimuli consisting of photoirradiation and the postbaking in the presence of a photo acid generator.

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A highly sensitive photopolymerization system by using violet laser, 405nm, was investigated. The photopolymerization composition which contained an initiator and a high fluorescent dye showed efficient sensitization of the system. The photosensitization mechanism seemed to have a singlet energy transfer process. A key molecular design of the dye getting the higher photosensitization efficiency is a repression of thermal relaxation from the excitation state. The photopolymerization system was applied to the computer to plate (CTP) technology, a digital printing plate, to develop our i-Presso P-NV for the violet laser. As compared with a system using a conventional FD-YAG laser, the P-NV system revealed the advantage of high productivity on plate making and also handling under a brighter safelight.

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Three series of alkyl methacrylate based copolymers having photo-reactive side chains (C=C double bond) were synthesized and examined their performances as photopolymer in the presence of suitable oxime ester or triazine type radical photo-initiators for 365 nm light. Along to our previous report showed that correlation was observed between photochemical reactivity and chain length of the side chain/density of reactive side chain in the cyclohexyl methacrylate main chain. Our proposed mechanism is that sterically stacked nonpolar cyclohexyl groups may push out the polar reactive side chains, and length and density of the side chain controls cross linking between two reactive sites in the single main chain or two different main chains. Now we have examined structural effect of the alkyl groups on the efficiency of photocrosslinking. We have examined 5 series and totally 15 polymers. As a result, cyclohexyl methacrylate based copolymer showed excellent performance for polymerization.

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Hydroxycinnamate derivatives which are polymerizable phenolic acids show two-types photoreactions such as intramolecular E-Z isomerization and intermolecular [2 + 2] cycloaddition. Although five derivatives of hydroxycinnamic acid were tried to polymerize by a conventional one-bottle method, only two polymers of poly(3-hydroxycinnamic acid) (P3HCA) and poly(3,4-dihydroxycinnamic acid) (PDHCA) were successfully prepared. Because these polymers had cinnamoyl moiety in every main-chain unit, the polymers should show efficient photoreactions by the UV irradiation. The hard-film of these polymers showed a photo-bending behavior. Furthermore, the photo-bending showed generation of high-power (170μN).

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Graft polymerization is one of the surface modification methods for organic solid. When organic solids are irradiated by electron beam (EB), activation sites can be generated in the polypropylene and monomer reacts at the active site to grafted chains. First-step polymerization proceeded during EB irradiation. And then, the fiber was heated at high pressure to promote second step grafting with high propagation rate. The generated chains have bimodal distribution in molecular weight and high molecular weight component gradually increased with polymerization pressure for second grafting. The molecular weight of grafted chains and their distribution are evaluated from those for the extracted solution polymers. Temperature dependence of grafting efficiency gave us thermodynamic parameters for the grafting polymerization.

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