Hexaphenylbisimidazoles with methoxy and nitro substituent in 2-phenyl ring were synthesized and evaluated by UV-vis absorption spectrum, photo-dilatometer and photoresist dry film. Both methoxy and nitro group shift the UV-vis absorption spectra of HABIs to a longer wavelength by comparison with the parent HABIs. The UV-vis absorption spectrum of B1-HABI exhibits a 13nm redshift than TCTM. Photo-dilatometer experiments indicate that their photoinitiating efficiencies are higher except B3-HABI. The dry film photosensitivity of B1-HABI at 365nm and 405nm are much better than traditional HABIs.

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The substituent effect of fluorine-containing polyimides with 4,4-(hexafluoro-isopropylidene) diphthalic anhydride (6FDA) group on the photo alignment of the liquid crystal (LC) molecule and the effect of 254 nm linearly polarized ultraviolet (LPUV) irradiation on the chemical structure were systematically investigated. 6FDA-2,3,5,6-tetramethyl-1,4-phenylene diamine (TeMPD) showed the photo alignment characteristic of the LC molecule. Based on the infrared and ultraviolet absorption spectra, the photo-scission reaction of LPUV irradiation was not observed, though photoreaction between polymer segments was observed. The photo alignment characteristic of LPUV-irradiated 6FDA-TeMPD strongly depended on the photoreaction between the C=O group of the imide ring and the CH₃ group for phenyl-group π-π^* transitions. The chemical structure changed with the excitation of C=O double bonds and C-H bonds and the formation of hydroperoxide O-H between the intermolecular polymer segment through the LPUV irradiation mechanism. The electron-donating benzene ring and the electron-accepting imide ring then formed charge transfer complexes (CTCs) between the two sides of polymer chains; the combination with the alternation sequence to both cross sides was clearly formed. In one direction of the photoreaction in the CTC structure, 6FDA-TeMPD showed the photo alignment of the LC molecule.

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Negative photopolymerizing photoresists can be cured in a short time, as compared to thermosetting photoresists, and have advantages in reducing the energy, cost and volatile organic compound (VOC) generated therefore. They are utilized as a curing system for large-size liquid crystal panels, of which sizes are lengths more than 2 m. Therefore, novel photo polymerization initiators, which generate radicals more efficiently, have been investigated. However, compounds which substitute phenyl group in the oxime end have promptly occurred to E/Z-isomerization around C=N bonds. This isomerization remarkably decreases quantum yield of radical production in N-O bond cleavage. The authors investigate the influence to photolithography by the isomeric structure of O-acyloxime ester compounds and the selective synthetic process of isomeric structure. Consequently, a selective isomer synthesis method for E and Z isomers has been established by controlling the reaction temperature. Furthermore, evaluations of the pattern formation using these isomers areperformed. The evaluations have revealed that patterns are formed by using the E isomer with lower energy than that required by using the Z isomer.

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We synthesized a cross-linker incorporated tetra-c-methyl-calix[4]resorcinarene (C4RA) derivatives. Molecular glass resists based on the C4RA derivatives showed a high sensitivity (20 mJ/cm²), making it possible to fabricate a 4-μm line-and-space pattern under a 365-nm light (i-line) exposure. Furthermore, an 80-nm L/S pattern could be observed by electron-beam exposure.

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As extreme ultraviolet (EUV) lithography enters the commercialization phase with potential introduction at the 3x nm half-pitch node in 2013, the attention of advanced EUV resist research has turned to addressing patterning at 16-nm half pitch and below. Whereas line-edge roughness is the primary concern at 2x half pitch and larger, research at the 16-nm half pitch level is uncovering broader.

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This paper aims to investigate the residual film thickness of negative photoresist with varied exposure dose after developmemt, namely, the contrast curve, affected by the photoinitiators. Three kinds of photoinitiators (Irgacure 369, Irgacure 907, and Irgacure OXE-02) were used as studied materials, blending with carboxylated cresol acrylic resin and trimethylolpropane triacrylate in co-solvent of propyleneglycol monomethyl ether acetate and cyclohexanone. As shown in the results, the photoinitiator grouped with oxime ester, such as Irgacure OXE-02, can be used to increase the contrast of negative-work photo-resist in the photolithography, and reduce the exposure dose needed for cross-linking reaction due to the more free radicals produced by the photoinitiator with a wider spectral absorption range. This suggests that the contrast curve method may be employed to optimize and integrate the photosensitive polymer in the photolithography process.

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A micro polymer capsule of 6.5mm length and 4.0mm diameter is fabricated by multi laminating method. The micro polymer capsule has 56 micro pillars for generating a turbulent liquid flow in the inside of capsule. As a fabrication process, the SU-8 resist film based on epoxy resin is coated on a glass substrate. A ring shape image is exposed on the resist film. After pattern development, the ring patterns are peeled from the glass substrate by dipping into HF aqueous solution. The SU-8 ring patterns are stacked in 18 layers by using the micro tweezers under the alignment accuracy of ±0.3mm. In order to adhere the SU-8 ring layers each other, an i-line resist material is pasted into SU-8 ring patterns, then baked on a hotplate at 200°C for 10min. These functional capsule structures can contribute to develop various biological and medical MEMS(Micro Mechanical electronic system) devices.

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In two-photon lithography a high repetition rate laser scans through calculated trajectories in order to induce polymerization in the resin which give rise to complex microstructures. When there are sharp angles within trajectories, the polymerized resin at angles receives more energy from the laser. The polymerized structure becomes larger, and the produced shape gets over-exposure defects. Here we have modeled over exposure defects using numerical simulations and suggested an analytical expression to calculate the correcting coefficients for adjusting laser power. We have demonstrated over exposure defect of free angular structures using this laser power correction.

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A series of resolution enhancement materials (REMs) for 193-nm resist employing poly(vinyl alcohol), 2-hydroxybenzyl alcohol (2HBA), and a non-ionic surfactant have been prepared and evaluated. The resolution enhancement has been achieved by resist pattern thickening (pattern space shrinkage) that is caused by the interaction between REMs and 193-nm resists. The key component, 2HBA, demonstrated the capability of shrinkage of the printed spaces or holes on 193-nm resists without a cross-linking reaction. This system expanded the process margin and minimized the dependence of resist pattern sizes, pitches, and shapes in the shrinkage reaction that had been one of the critical issues in the cross-linking-type chemically shrinking materials. The optimized REM afforded about 10 to 15-nm shrinkage for hole, trench, and lines and spaces (L/S) patterns with various pitches that was suitable for advanced Logic LSI application.

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