Development of Electrochemical Microfabrication Techniques and its Application

本研究项目旨在发展电化学法沉积导电层的电化学微细加工技术，并将其应用于电化学分子器件。目前电化学金属沉积技术中最重要的技术之一是电路板的制造，而驱动技术的强烈要求是小型化、高通孔比和具有良好机械性能的高质量镀层。在这方面，有一部分工作致力于与一个行业合作，研究激光辅助电镀和有机添加剂效应，以改善机械性能。激光辅助金属沉积及电镀微细加工技术研究(1)激光辅助电镀对无掩膜高速电镀有一定的应用价值，但镀层质量不佳。(2)在工业化学镀铜中，添加2，2‘-联吡啶是生产…的有效方法更多高质量的铜膜。我们利用表面增强拉曼光谱、原位红外光谱和电化学阻抗谱等多种技术来揭示吸附分子的结构，并获得了有趣的结果。除了上述微观研究外，还引入了一种新的技术，即小角度入射原位X射线衍射法，以确定在添加和不添加添加剂的情况下生长的沉积层的晶体尺寸。2，2‘-联吡啶存在下Cu2O杂质的形成和曝气分解的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)发展了各种类型的铂、金和ITO微阵列电极的制备技术，即交指阵列电极和独立电极阵列电极，其间距和电极宽度为4-20微米。还制备了亚微米尺寸的圆盘型超微电极。对于圆盘型电极，已经集中精力将尖端直径减小到几个微米，包括绝缘体护套，并利用化学镀银的方法研制了超微环电极。利用微阵列电极系统，我们尝试构建了具有氧化还原循环电化学放大功能和多功能流出时间和电极电位显示的高效液相检测器等电化学器件。在这项工作中注意到的另一个有趣的应用是开发响应化学信号的电化学数字设备。我们发现，与电聚合法沉积的聚吡咯薄膜相互连接的电极阵列对pH的变化非常敏感，相邻带阵列之间的电导率变化很大，这与FFT器件的行为相似。在此基础上，发展了聚吡咯与酶的集成体系--pH开关和酶开关。较少

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