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所特有的物种的非线性扩散的控制和利用。在第一年的研究中，证实了金属物种在硅片表面纳米缺陷处的优先电化学沉积，并利用这一点开发了金属纳米结构的制备工艺。用从头算分子轨道计算方法对金属团簇表面还原物种的反应进行了定量分析。此外，还对光照辅助阳极氧化工艺的应用进行了尝试，开发了硅纳米加工工艺，并采用孔型结构控制光照条件，控制空穴向反应部位的非线性扩散，实现了大孔阵列的均匀形成。I…第二年，对硅片表面金属纳米结构的制备工艺进行了改进，以实现对各种金属物种的进一步精确控制。尝试对硅微孔阵列进行改性，制备出可用作微反应器的微升体积玻璃管阵列。开发了一次批量制备孔阵列及其填充形成金属针阵列的工艺。此外，还对制备高性能ULSI的关键材料--应变硅表面的化学性质进行了理论分析，并定量地评价了表面反应性与应变程度之间的关系。最后一年，开发了玻璃管顶端通孔的制造工艺，形成了纳米喷嘴阵列。这一过程是通过控制腐蚀剂物种的非线性扩散来实现的。通过使用该工艺，尝试制造过滤装置和其他系统。此外，利用量子化学计算方法建立了化学沉积过程中还原剂反应性的定量评价方法。如上所述，用于精密纳米制造的新型电化学工艺已经被开发出来，并阐明了反应过程的详细机理。较少

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