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Sung Jin KIM Jong Hoon CHOI Hyung Tae KIM Hee Nam CHAE Sung Min CHO
Amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistor (TFT) was fabricated by an advanced self-aligned imprint lithography (ASAIL) method with a hybrid etching process. The SAIL is a top-down method to fabricate a TFT using a three-dimensional multilayer etch mask having all pattern information for the TFT. The hybrid etching process was newly applied in the original SAIL process for the purpose of reducing plasma damage of a-IGZO channel layer during plasma etching in the ASAIL process. This research demonstrated that the a-IGZO TFT could be successfully fabricated by the ASAIL process. In particular, the hybrid etching process applied in this paper can be utilized for the back-channel-etch type a-IGZO TFT and further extended for the roll-to-roll backplane process.
For the future medical diagnostics, high-sensitive, rapid, and cost effective biosensors to detect the biomarkers have been desired. In this study, the polymer-based two-dimensional photonic crystal (2D-PC) was fabricated using nanoimprint lithography (NIL) for biosensing application. In addition, for biosensing application, label-free detection of fibrinogen which is a biomarker to diagnose the chronic obstructive pulmonary disease (COPD) could be achieved using antigen-antibody reaction high-sensitively (detection limit: pg/ml order) and rapidly. Using this polymer-based 2D-PC, optical biosensor can be developed cost effectively. Furthermore, by using polymer as a base material for fabrication of 2D-PC, label-free detection of antigen-antibody reaction can be performed in visible region.
Wei-Chiun LIU Bin-Da LIU Chia-Ling WEI
A modularized, low-cost, and non-invasive electrochemical examination platform is proposed in this work. Melatonin has been found to be a possible significant indicator molecule in the detection of breast cancer. 3-hydroxyanthranilic acid and nuclear matrix protein 22 can be used as a significant index for potential bladder cancer risks. The proposed system was verified by measuring the melatonin, 3-hydroxyanthranilic acid and nuclear matrix protein 22. Cyclic voltammetry and molecularly imprinted polymers were used in the experiments. Screen-printed electrodes were coated with a film imprinted with target molecules. The measurement results of the proposed system were compared with those of a commercial potentiostat. The two sets of results were very similar. Moreover, the proposed system can be expanded to a four-channel system, which can perform four measurements simultaneously. The proposed system also provides convenient graphical user interface for real-time monitoring and records the information of the redox reactions.
The individual steps of UV imprint lithography have been explained in detail from the points of manufacturing nano-structures. The applications to photonic devices have been also introduced.
Nobuya HIROSHIBA Wataru YANO Ryuji OKUMURA Yo ICHIKAWA
We demonstrated a novel technique to fabricate nanosized structures on a Nafion membrane, using thermal nanoimprinting with alinebreak $5 imes 5$,$mu $m$^{mathrm{2}}$ square pattern Si mold without any polymer damage. A 24,MPa thermal imprinting pressure was used for 10,min. We observed high aspect ratio ($sim$1:10) pillars on the surface after imprinting at 200$^{circ}$C. Finally, we used a novel quartz mold with a 200,nm resolution dot pattern.
Young Min KANG Seaung Suk LEE Beelyong YANG Choong Heui CHUNG Hun Woo KYE Suk Kyoung HONG Nam Soo KANG
Effects of imprint on signal margin in FeRAM with Pt/SrBi2Ta2O9/Pt capacitors have been investigated. Imprint, induced during high temperature storage, significantly reduced the signal margin and hence determines lifetime of FeRAM. Initial signal margin of 470 mV is reduced to 290 mV after storage at 175C for 96 hours. From the reduction rate of the signal margin, it is estimated that imprint lifetime of the FeRAM is more than 10 years even though the storage temperature is 175C.
Naoki IZUMI Yoshikazu FUJIMORI Takashi NAKAMURA Akira KAMISAWA
Pb(ZrxTi1-x)O3 (PZT) thin films were prepared on various electrodes. When Ir system materials were used as electrodes, fatigue properties of PZT thin films were improved. Moreover, in the case of the PZT thin film on an Ir/IrO2 electrode, not only fatigue but imprint properties were clearly improved. We could find these improvements were caused by good barrier effect of IrO2 from secondary ion mass spectroscopy (SIMS) analysis. By applying these Ir system electrodes, we fabricated stacked capacitors on polycrystalline silicon (poly-Si) plugs. In spite of high temperature thermal processing, we found poly-Si plugs were ohmically connected with the bottom electrodes of the capacitors from hysteresis measurements and I-V characteristics, and could greatly expect them for practical use.
An annoying problem encountered in automatic seal imprint verification is that for seal imprints may have a lot of variations, even if they are all produced from a single seal. This paper proposes a new automatic seal imprint verification system which adds an imprint quality assessment function to our previous system in order to solve this problem, and also examines the verification performance of this system experimentally. This system consists of an imprint quality assessment process and a verification process. In the imprint quality assessment process, an examined imprint is first divided into partial regions. Each partial region is classified into one of three quality classes (good quality region, poor quality region, and background) on the basis of characteristics of its gray level histogram. In the verification process, only good quality partial regions of an examined imprint are verified with registered one. Finally, the examined imprint is classified as one of two types: a genuine and a forgery. However, as a result of quality assessment, if the partial regions classified as poor quality are too many, the examined imprint is classified as ambiguous" without verification processing. A major advantage of this verification system is that this system can verify seal imprints of various qualities efficiently and accurately. Computer experiments with real seal imprints were performed by using this system, previous system (without image quality assessment function) and document examiners of a bank. The results of these experiments show that this system is superior in the verification performance to our previous system, and has a similar verification performance to that of document examiners (i.e., the experimental results show the effectiveness of adding the image quality assessment function to a seal imprint verification system).