Development of Novel electrochemical Nanofabrication Processes through Controlling Non-linear Diffusion

本研究的目的是通过电化学方法开发金属纳米结构的新型纳米加工工艺。特别强调了电化学过程中所特有的物质非线性扩散的控制和利用。在第一年的研究中，确定了金属在硅片表面纳米缺陷位置的优先电化学沉积，并利用这一点开发了金属纳米结构的制造工艺。同时，利用ab-initio分子轨道计算方法对还原剂在金属簇表面的反应进行了定量分析。此外，还尝试将照明辅助阳极氧化工艺应用于硅纳米加工工艺的开发，并利用类孔径结构控制光照条件，控制孔洞向反应位点的非线性扩散，实现了宏观孔洞阵列的均匀形成。在第二年，改进了硅晶片表面金属纳米结构的制造工艺，实现了对各种金属种类的进一步精确控制。尝试对硅宏观孔阵列进行改性，制备适用于微反应器的微升体积玻璃管阵列。开发了单批制备孔阵列及其填充形成金属针阵列的工艺。此外，对制备高性能ULSI的关键材料——应变Si表面的化学性质进行了理论分析，并定量评价了表面反应性与“应变程度”的相关性。在最后一年，开发了玻璃管尖端通孔的制造工艺，形成“纳米喷嘴”阵列。这个过程是通过控制蚀刻剂的非线性扩散来实现的。利用这一工艺，尝试了滤波装置和其他系统的制造。此外，利用量子化学计算方法建立了化学沉积还原剂反应性的定量评价方法。如上所述，开发了用于精密纳米加工的新型电化学工艺，并详细阐明了反应过程的机理。少

The objective of this research was to develop novel nanofabrication processes of metal nanostructures trough electrochemical approaches. Especially, control and utilization of the nonlinear diffusion of the species, which is unique to the electrochemical processes, were emphasized. In the first year of the research, preferential electrochemical deposition of metal species at the nano-defect sites on Si wafer surface was confirmed, and by utilizing this, fabrication process of metal nanostructure was developed. Also, quantitative analysis was made for the reaction of reductant species at the surface of metal cluster using ab-initio molecular orbital calculation. In addition, attempt on the application of illumination-assisted anodization process was made to develop Si nanofabrication process, and by controlling the illumination condition using aperture-like structure, which controls nonlinear diffusion of holes to the reaction sites, uniform formation of macro pore array was achieved. I … More n the second year, the fabrication process of metal nanostructure onto Si wafer surface was improved to achieve further precision control for various metal species. The modification of the Si macro pore array was attempted to fabricate pico-liter volume glass tube array which is applicable as microreactors. The single-batch process to fabricate the pore array and its filling to form metal-needle array was also developed. In addition, theoretical analysis on the chemical properties of strained Si surface, which is key material for fabricating high-performance ULSI, was also attempted and the correlation between the surface reactivity and "degree of strain" was quantitatively evaluated. In the final year, fabrication process for through-hole to the tip of the glass tube was developed to form "nano-nozzle" array. This process was achieved by controlling the nonlinear diffusion of etchant species. By using this process, fabrication of filter devices and other systems was attempted. In addition, quantitative evaluation procedure of the reactivity of reductant for electroless deposition process was established using quantum chemical calculation approaches. As described, novel electrochemical processes for precision nanofabrication have been developed and detailed mechanism of the reaction processes has elucidated. Less