The Photopolymer Science and Technology Award No. 061100, the Outstanding Achievement Award 2006, was presented to Masahiro Tsunooka (Osaka Prefecture University) for his outstanding achievements in photopolymer science and technology, "Development of Photoacid and Photobase Generators and Their Application to Design of Novel Photopolymers".

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The Photopolymer Science and Technology Award No. 062100, the Best Paper Award 2006, was presented to Mireille Maenhoudt, Geert Vandenberghe, Monique Ercken, Shaunee Cheng, Peter Leunissen and Kurt Ronse, all from IMEC, for their outstanding contribution published in Journal of Photopolymer Science and Technology 18(5), 571-577 (2005), entitled "Opportunities and Challenges in Immersion Lithography".

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Relationships between the HOMO energy and σ(p) in ylides 1-14 have been studied. Linear relationships between the HOMO energies obtained by HF/3-21G[^*] and 6-31G^*, BLYP/6-31G^*, and B3LYP/6-31G^* methods and the substituent constant (σ(p)) were found, respectively. Hence, for the electron donation of the ylide, it is noted that the HOMO energy can be used as a new parameter for predicting the basicity of SN ylides. By comparing the results obtained by these calculations, the best method is found to be B3LYP/6-31G^*. The results of bond lengths and torsion angles obtained by DFT calculations correspond with that of X-ray structure determinations.

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Confused hexaphyrin derivatives were excited by femtosecond pulsed laser to study transient responses. An extended ?-conjugated system showed characteristic absorption changes with relatively weak power of laser irradiation. Recovery of transient bleaching was observed with time constants less than 100ps by both 400nm and 800nm excitation. Copper complex derivative showed the fastest response of 21 ps. Optical responses in the visible region and its mechanism are discussed.

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We have reported the spectroscopic behaviors of polymeric pyridine derivatives, poly(vinylpyridines) (PVPys), using excitation emission matrix (EEM). As PVPys show complicated fluorescence spectra, EEM would be an effective tool to make the details of the photochemical reaction of PVPys clear. In this study, we apply EEM to polarized fluorescence measurement, and show 2-D mapping of emission anisotropy. We also show a new attempt of analyzing transition moment-distribution of the fluorophore in thin films using polarized fluorescence.

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Novel photoresponsive and liquid crystalline conjugated polymer was synthesized by introducing the dithienylethene moiety into the side chain of poly-para-phenylenevinylene (PPV). Observation of polarizing optical microscope demonstrated that the polymer exhibits a main-chain type liquid crystallinity. Reversible photochemical isomerization of the dithienylethene moiety was observed in both in CHCl3 solution and in cast film. Fluorescence of the polymer was drastically quenched when the photochromic moiety changed from an open form to a closed one upon irradiation of ultraviolet. The quenched fluorescence was well recovered through the reverse photoisomerization from the closed to open form.

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The waveguide was fabricated by dispersal of a compound with a higher refractive index into poly(methyl methacrylate). Preparation of the waveguide was performed by the vacuum process. The doped region showing the higher refractive index acted as a core, and non-doped matrix PMMA surrounding the core acted as a cladding layer. The refractive index of core was controlled by the treatment temperature. As the waveguide prepared in the present study possessed a large core size, it was favorable for the short-range optical network.

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Infrared-to-visible upconversion emission was used for photocuring of a pentaerythritol tetraacrylate (PETA) by infrared laser irradiation to achieve local polymerization on an upconversion phosphor. Submillimeter-sized, cone-shaped and solid poly (PETA) was successfully formed on a Y₂O₃ compact doped with 5 mol% Er under 985 nm diode laser irradiation with about 900 mW power. By changing the irradiation time, it was found that the formation of the cone starts in seconds and takes minutes to form a millimeter-sized cone. The correlation between the irradiation time and the cone volume was linear in the seconds-to-minutes time region with 800-900 mW irradiation powers.

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This paper describes a study of a cross-linking reaction model for chemically amplified negative-type thick-film resists. Profile simulation is a major technique used to acquire experimental indicators. For this reason, numerous reports address simulation techniques, and many studies have focused in particular on chemically amplified positive-type resists, due to their role as mainstream resist materials used in the production of ICs. However, virtually no research has been performed on the profile simulation of chemically amplified negative-type thick-film resists.
We measured the cross-linking reaction of a chemically amplified negative-type thick-film resist and created a new cross-linking reaction model. Our study demonstrates that this new model is more effective for thick-film resists than conventional models.

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The permanent film photoresist is a versatile material in the MEMS field. The formation technology of the minute tunnel structure with the permanent photoresist is watched with keen interest. The encasing of the semiconductor device with the minute tunnel structure to be used as a SAW (Surface Acoustic Wave) and BAW (Bulk Acoustic Wave) Filter, application as a ink jet head nozzle or micro channel for the semiconductor as a radiator are some of it potential applications.
We have established a unique technology named Tenting by using a liquid resist and a dry film resist. This paper will present the Tenting method in detail.

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Novel photoacid and photobase generators for photopolymers developed in our laboratory are reviewed. Oxime sulfonates derived from 9-fluorenone and thioxanthone and imidosulfonates with thioxanthone skeleton or thianthrene moiety were developed as the i-line sensitive photoacid generators. Their photochemistry at i-line irradiation and their use in the photocrosslinking of polymers with pendant epoxy groups were investigated. The novel photosensitive polymers which are crosslinked photochemically in the presence of photoacid generators and the resulting crosslinked one can be degraded by the acids were developed. Carbamoyloximes, carbamates with imido structure, and quaternary ammonium salts were investigated as photobase generators. Copolymers with pendant carbamoyloxime moiety were proved to be very effectively crosslinked with photo-irradiation followed by baking, because amino and isocyanato groups, which were generated photochemically and thermochemically, respectively, promoted the formation of urea linkages. Thermal stability on latter two photobase generators is discussed. Copolymers with pendant acyloxime units in the block in both ends were found to be more effective crosslinkers for poly(glycidyl methacrylate) than those with random pendant groups. Novel photopolymers using photobase generators, which were photochemically crosslinked and followed by thermal degradation, were developed.

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We evaluated the resolution and sensitivity of a resist with and without hexamethyldisilazane (HMDS), which improves resist adhesion to substrates, by using profilometry. HMDS was spin-coated onto a Si wafer by using a spin coater. The resist with HMDS was always thicker than that without HMDS for the same exposure dose. The resist pattern profile (resolution) with HMDS was better than that without HMDS. We found that UV absorbance of the resist with HMDS was greater than without HMDS. The resist was mixed with HMDS, and the phenolic hydroxyl groups of the resist were silylated by HMDS. The light through the resist was absorbed in the mixed layer. Also, the mixed layer weakened the reflected light from the Si substrate. We demonstrated that the mixed layer generated by resist with HMDS works as an antireflection coating for the resist.

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The binary hologram master for hologram color filter were developed and evaluated in their characteristics. The chirped diffraction grating was fabricated by electron-beam lithography. EB direct-writing has an excellent lateral accuracy and uses only one exposure step. This effect leads to undesired exposure of the resist in regions adjacent to those actually addressed by electron beams. The authors design binary surface-relief gratings, optimization of groove profiles of the EB master hologram, thereby efficiently coupling light was achieved into the first diffracted order. The authors have produced grating that have 1st-order diffraction efficiencies greater than 90 %. This manufacturing process was consisting from a volume hologram master and contact print process. The mass production of such HOEs (Hologram Optical Elements) would be possible by the development of a precise replication technology from EB lithographed elements.

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The novel electron beam (EB)-induced color imaging system, consisting of polymer films with acid-responsive chromic molecules (chromic dyes) and EB-acid generators (EBAGs) was proposed. EB irradiation of the acid-chromic polymer films induced acid generation from EBAG, resulting in color formation of the acid-chromic molecules (protonated forms). Nanoscale color imaging on the acid- chromic polymer films was carried out using EB scanning direct drawing. Clear color imaging of 200 nm square and 100 nm line/space patterns could be observed with a dose of only 50 μC cm^-2. Furthermore, the large EB-induced refractive index change of these films (∼0.013 at 632.8 nm) was observed in both TE and TM modes by an m-line method, which is sufficient to create an optical circuit.

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The organic polymers, polyimide thin films and PMMA plate, were photo-catalytically machined by use of the porous Ti0₂ micro wire which was prepared by the phase separation-selective-leaching method. The photocatalytic decomposition of a nanometer range in depth occurred in all the polymer surfaces. The photo decomposition rate was different among the samples. This difference was attributed to that of the chemical bond strength of the polymers, and this mechanism of the photo decomposition by Ti0₂ micro wire was discussed from the results of the IR-ATR spectroscopy measurements.

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Refractive index change was induced by electron beam irradiation to transparent polyimides as large as 10^-2. Active intermediates during the electron beam irradiation were determined by electron beam pulse radiolysis of several model imide compounds. Strong electron affinity of the transparent polyimides was one of the key factors for the reaction.

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The fabrication of polytetrafluoroethylene (PTFE) and polyimide (PI) layered films has been demonstrated by high temperature soft electron beam (soft-EB) irradiation techniques. The PTFE dispersion has been coated by wire-bar coating equipment on PI thin film. The PI/PTFE layered films were irradiated by EB at 330°C± 3° C in nitrogen gas atmosphere. Characterization of soft-EB irradiated PI/PTFE films have been performed by X-ray photoelectron spectroscopy (XPS), thermal analysis (DSC and TGA), and so on. According to XPS analysis on PTFE coated side, the atom ratio of F/C, H/C and N/C were 2.44, 0.04 and 0.06, respectively. Thus, it was found the fluorine coated on PI surface, that is, PTFE molecule has been reacted with PI polymer chains by high temperature soft-EB irradiation. Moreover, the obtained hybrid films showed the good adhesive properties and lower crystallinity.

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When 18-crown-6(18C6) was added top p-substituted benzene diazo compounds (SBD) in methanol, λmax of SBD shifted to shorter wavelength, but did not shift in an aqueous solution. Degree of the shift with electron-withdrawing substituent (WSBD) was larger than that with electron-donating substituent (DSBD). WSBD with poor electron density was coordinated by six oxygen atoms of 18C6 more tightly than DSBD. Photo decomposition of SBD with 18C6 in methanol were suppressed through the coordination. Photo decomposition of WSBD were slightly suppressed with polyethylene glycol 300 (PEG), while did not change with β-cyclodextrin (CD). Thermal decomposition of DSBD with 18C6 in methanol and an aqueous solution were suppressed similarly to that of photodecomposition in methanol. Thermal decomposition rate of SBD can be suppressed through the complex formation by adding PEG or CD, and the rate may be accelerated with the coexistence of hydroxy groups. These results indicate that; when DSBD with 18C6 are used for information recording materials, thermal stability will be improved. DSBD with CD will be improved in thermal stability without decreasing sensitivity. When WSBD with CD or PEG were used for acid generators for polymerization, the rate will increase.

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Under UV light irradiation at 313 nm, a gaseous mixture of cobalt tricarbonyl nitrosyl (Co(CO)₃NO) and carbon disulfide (CS₂) produced sedimentary aerosol particles involving organometal compounds. From measurements of monitor (He-Ne laser) light intensity scattered by the aerosol particles and FT-IR band intensity change of the gaseous molecules, it was shown that the nucleation process of the aerosol particles was accelerated with increasing partial pressure of CS₂. Chemical structure of the sedimentary particles was analyzed by FT-IR and X-ray photoelectron spectra (XPS). The results showed that excited Co(CO)₃NO molecules reacted with CS₂ molecules to initiate the nucleation reaction of particle formation and NO group in Co(CO)₃NO was removed during the particle formation. With the application of a magnetic field, CS₂ molecules were found to be incorporated into the aerosol particles in a greater amount. Chemical reactions between Co(CO)₃NO and CS₂ that were responsive to the magnetic field were briefly discussed.

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