Researchers are currently examining various methods for determining the quantity of acid generated by a photoacid generator (PAG) and for analyzing acid-generating reactions using acid-sensitive dyes that react with acid and generate a color. Adding an acid-sensitive dye to the resist gives a clear grasp of the acid-generating action. The process involves applying a resist containing an acid-sensitive dye to a quartz substrate; exposing the substrate; and measuring and evaluating the absorbance of a chromogenic substance near 530nm using a spectroscope. The method determines the rate constant for acid generation (Dill C parameter) during exposure based on the relationship between transmissivity at 530nm and exposure dose. Using this method, we obtained and compared rate constants for acid generation (C parameters) as part of our study of dependence on the quantity of quencher in the EUV resist. Our results indicate a new model that accounts for the quencher concentration parameter would be useful in analyzing dependence on the quantity of quencher. This paper presents these findings, together with the results of studies of profile simulations using the quencher concentration parameter obtained in the experiments.

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Whole field dark field monitoring system was constructed for observation of UV curable resin filling and detection of bubble defects of UV nanoimprint. Patterns with μm dimensions were observable by the monitoring system and filled/unfilled patterns were easily identified by the observed images. From full-area observations by the system, archipelago-like contact phenomenon was found in the contact front between a mold and UV curable resin on a wafer. The archipelagos were merged each other and were instantaneously banished with proceed of contact in the case of UV nanoimprint in pentafluoropropane (PFP). On the contrary, numerous bubbles were created even at unpatterned areas of a mold by the above phenomenon and were preserved for prolonged time in the case of UV nanoimprint in air. The portions detected by the monitoring system as unfilled were compared to the corresponding those images of UV nanoimprinted sample taken by an optical microscope at high magnifications. It was found that the monitoring system gives very correct evaluation of unfilled portions. The whole field dark field monitoring system is a simple but powerful tool for evaluation of resin filling processes.

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The detection and evaluation of printable defects in extreme ultraviolet lithography (EUV) masks are one of the most critical issues for high-volume manufacturing of next generation semiconductor. The coherent EUV scatterometry microscope is a strong candidate for high-precision inspection of defects. We have developed the high-order harmonics generation system to generate coherent EUV light using the commercial table-top laser system. The low beam divergence was measured to be 0.18mrad for 13.5nm (59th) high-order harmonics. The spatially coherent, 59th harmonics was improved the contrast ratio of diffraction images. Defect signals were observed from the 2-nm width line-defect in the 88-nm line-and-space (L/S) pattern and the 54-nm defect in the 360nm pitch pattern using coherent scatterometry microscope equipped with high-order harmonics generation system as a practical coherent EUV light source.

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Precise micro-coils and mesh pipes with outer and inner diameters of 100 and 60μm were fabricated using laser-scan lithography and electrolytic etching. Non-magnetizable stainless-steel (SUS304) pipes were coated with resist films, and helical patterns were delineated using a laser-scan exposure system. Positive resist PMER P-LA900 was used for fabricating micro-coils, and negative resist PMER N-CA3000 was used for fabricating micro-mesh pipes. Mesh patterns were formed by doubly delineating helical patterns coiled in opposite directions each other. Widths of resist patterns used for fabricating mesh patterns were also controlled by stitching two helical patterns. Because space widths of coils and sizes of mesh holes became larger than space widths and hole sizes of resist patterns caused by undercut in etching process, widths of resist patterns were adjusted by considering the undercut depths. As a result, pipe specimens were suitably etched in a solution of sodium chloride and ammonium chloride in water, and micro-components with homogeneous widths were successfully fabricated.

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We have studied self-absorption effects of a laser-produced plasma (LPP) source at 6.xnm as a function of laser pulse duration and viewing angle. The spectral profiles are shown to have a strong dependence on viewing angle. Absorption effects are less pronounced when a 150-ps pulse duration is used due to reduced opacity resulting from plasma expansion. Conversion efficiencies and ion energies are also measured as a function of laser pulse duration and laser power density. A maximum conversion efficiency of 0.4% within a 0.6% bandwidth was measured, and lower ion kinetic energy was observed. It is concluded that in order to reduce self-absorption effects and ion yields, and increase conversion efficiencies, a short pulse duration should be used.

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Directed self-assembly (DSA) lithography are recently getting in the spotlight as one of the most promising new generation lithography (NGL) candidates, which have a potential to fabricate semiconductor device patterns down to sub-30nm. In this report, latest experimental and simulation results of contact hole shrink process using the DSA are demonstrated.

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Safety standards and guidelines for radio-frequency exposure are being set based on whole-body averaged SARs (WBA-SARs) and localized average SARs. In Japan, the WBA-SAR and 1g localized average SAR are set at 0.4W/kg and at 8W/kg, respectively, except for the arms and legs and surface of body. The safety limits of WBA-SARs were determined from observing the behavior destruction of animals for radio-frequency exposure, but those of localized average SARs were determined under the assumption that a spatial peak SAR value does not exceed 20-fold WBA-SARs without their biological evidences. In this paper, to confirm whether or not the above assumption is valid, we calculated WBA-SARs and voxel SARs in the frequency range from 50MHz to 2GHz in anatomical-based human numerical models for pregnant woman and 3-years child for vertically and horizontally polarized far-field exposures, and derived the histogram and cumulative relative frequency of voxel SARs to obtain the quantitative relationship between WBA-SARs and voxel SARs. As a result, we found that 99.90-percentile voxel SARs are not exceeding 20-fold WBA-SARs, while 99.00-percentile voxel SARs are smaller than 10-fold WBA-SARs in both human models.

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Bow-tie trees(BTTs) generated by contaminants, e.g., metal, amber(over cured resin), carbon, voids in insulators of XLPE cables still remain a factor contributing to the deterioration. In order to examine the influence of contaminants on the behavior of BTT generation, we performed several experiments using XLPE samples containing copper powder, finely divided over cured resin or micro voids as BTT nuclei. As a result of the experiments, in spite of the great difference in the distribution of particle diameter, the shape and permittivity of the nuclei, each sample containing the copper powder or the over cured resin showed a common dependence of the number of BTTs on the mean size of BTT nuclei. Consequently, there is no fundamental difference in these nuclei. We consider that the lower limit of the nuclei size suitable for BTT generation is determined by the local electric field at the tip of the nuclei and the upper limit of them is determined by the extent of the stagnation of ions around the nuclei. Moreover, we consider that the increase in the mean size of BTTs with the initial water content was caused by a relaxation effect on the local electric field due to absorbed water in XLPE samples.

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