Development of Electrochemical Microfabrication Techniques and its Application

本研究旨在发展电解及化学沉积导电层之电化学微细加工技术，并将其应用于电化学分子装置。目前电化学金属沉积技术中最重要的技术之一是PC板制造，并且驱动技术的强烈需求是小型化，更高的通孔电镀和具有良好机械性能的高质量沉积物。在这方面，一部分工作致力于与工业界合作，研究激光辅助电镀和有机添加剂的作用，以改善机械性能。激光辅助金属沉积及电镀技术电化学微细加工的研究（1）激光辅助电镀是一种无掩模高速电镀技术，但镀层质量不高。(2)在工业化学镀铜中，添加2，2'-联吡啶在生产中是相当有效的 关于我们 高质量的Cu膜。我们应用各种技术，如表面增强拉曼光谱，原位红外光谱和电化学阻抗谱来揭示吸附分子的结构，并获得了有趣的结果。除了上述的微观研究，一种新的技术，低角度入射原位X射线衍射，已被引入到确定的晶体尺寸的沉积物生长和没有添加剂。晶体尺寸与添加剂浓度之间的相关性以及2，2'-联吡啶存在下杂质Cu_2O的生成和曝气分解的研究结果将为改进现有的电镀工艺提供有用的信息.微电极的制备及其在电化学分子器件中的应用（1）Pt、Au和ITO等不同类型微阵列电极的制备技术。例如，已经开发了叉指阵列和独立电极阵列电极，其间隙和电极宽度尺寸为4-20 μ m。还制备了亚微米尺寸的圆盘型超微电极。对于盘形电极，已经集中精力将尖端直径减小到几微米，包括绝缘体护套，并且使用Ag的无电沉积开发了超微环电极。铂涂层的银环电极用于在单个原生质体细胞中的电流型胞间伏安法。(2)使用微阵列电极系统，我们已经尝试构建电化学装置，如HPLC检测器，其通过氧化还原循环提供电化学放大，并具有流出时间和电极电位的多功能显示。在这项工作中注意到的另一个有趣的应用是响应化学信号的电化学数字设备的开发。我们发现，与薄聚吡咯膜电聚合沉积互连的电极阵列显示出敏感的响应pH值的变化，给相邻的带阵列之间的电导率变化，类似于FFT器件的行为。基于这一发现，已经开发了聚吡咯和酶的集成系统的pH开关和酶开关。少

This research project aimed at developing the electrochemical microfabrication technology in electrolytic and electroless deposition of conducting layers and at applying it to electrochemical molecular devices. One of the most important technology in electrochemical metal deposition at present is PC board manufacturing and strong demands driving technology are miniaturization, higher aspect ratio through hole plating and high quality deposits with good mechanical properties. In this connection a part of work was devoted to collaborate with an industry to study laser-assisted electroplating and organic additive effects to improve the mechanical properties.1. Studies on laser-assisted metal deposition and electrochemical microfabrication by plating techiques(1) Laser-assisted electroplating seems to be useful for maskless high speed plating, but the quality of deposits was not good.(2) In industrial electroless Cu plating, the addition of 2, 2' bipyridyl is quite effective in production … More of high quality Cu film. We applied various techniques such as surface enhanced Raman spectroscopy, in situ IR spectroscopy and electrochemical impedance spectroscopy to reveal the structure of adsorbed molecules and obtained interesting results. In addition to the above microscopic studies, a new technique, low angle incident insitu X ray diffraction, has been introduced to determine the crystal size of deposits growing with and without the additive. Results of correlation between the crystal size and the concentration of additive, and of the formation of Cu_2O as impurity in the presence of 2, 2' bipyridyl and its decomposition by aeration will provide useful information to refine the existing plating processes.2. Fabrication of microelectrodes and its application to electrochemical molecular devices(1) Fabrication techniques for various types of microarray electrodes of Pt, Au and ITO, i. e., interdigitated array and independent electrode array electrodes, has been developed, of which dimension are 4-20 mum in gap and electrode widths. Sub-micron size disk type ultra-microelectrodes were also fabricated. As to the disk type electrode concentrated effort has been done to reduce the tip diameter to few microns including an insulator sheath, and ultra-micro ring electrodes were developed using electroless deposition of Ag. Platinum coated Ag ring electrodes were used for amperometric intercelluar voltammetry in a single protoplast cell.(2) Using microarray electrode systems, we have tried to construct electrochemical devices such as HPLC detectors provided with electrochemical amplification by redox cycling and with a multi-functional display of effluent time and electrode potential. Another interesting application noticed in this work is development of electrochemical digital devices responding chemical signals. We found that the electrode array interconnected with thin polypyrrole films deposited by electropolymerization shows a sensitive response to pH change, giving large conductivity change between adjacent band arrays, similar behavior to FFT device. Based on this finding, pH switchs and enzyme switches which are integrated systems of polypyrrole and enzymes have been developed. Less