Fundamental technology for nano-device fabrication utilizing nanocomposite substrates

本研究的最终目标是开发利用精确控制的纳米复合材料衬底和微等离子体技术制造纳米器件的基础技术。我们将这些技术应用于碳纳米管（CNT）的制备，并研究了无机纳米部件的低温加工技术，旨在实现未来纳米器件中的部件与部件的接触。（1）纳米复合薄膜基底上碳纳米管阵列的制备我们采用等离子体增强化学气相沉积法，以镍金属作为碳纳米管生长的催化剂，添加Mo、TiO_2和SiO_2等惰性物质，成功地制备了森林状的碳纳米管阵列。这种CNT阵列具有比简单的CNT阵列高两倍的场发射电流，这表明了自维持和长寿命场发射装置的可能性。纳米复合基板也适用于有机分子排列的基板。(2)利用微等离子体进行纳米布线的基础技术我们尝试了在大气压下，使用受限于小空间的微等离子体在低温下制备碳纳米管。以CH_4为原料，含Fe物质为催化剂，在直径小于100 μ m的玻璃毛细管中，通过微等离子体反应，在常压下不加热衬底，成功地制备了碳纳米管。在此阶段，碳纳米管形成在插入毛细管中用于点火的金属丝上或玻璃毛细管的内表面上。我们正计划改进这项技术，使之能够在任意位置存款碳纳米管。我们还开发了一种新的技术，在液体介质中的激光烧蚀，高品质的纳米颗粒的制备。

Final goal of this study is to develop fundamental technology for nano-device fabrication utilizing precisely controlled nanocomposite substrates and microplasma technology. We applied these techniques to carbon nanotube (CNT) fabrication and studied low-temperature processing technique for inorganic nano-parts aiming for future part-to-part contact in nanodevice.(1)Carbon nanotube array fabrication on nanocomposite thin film substratesWe succeeded in fabrication of forest-like CNT al-rays by plasma-enhanced chemical vapor deposition method using nanocomposite substrate composed of nickel metal as a catalyst for CNT growth and inert substances such as Mo, TiO_2 and SiO_2. Such CNT arrays have twice higher field emission current compared to simple CNT arrays, suggesting the possibility of a self-sustainable and long-life field emission device. Nanocomposite substrate is also applied for a substrate organic molecular arrangement.(2) Basic technology for nano-wiring utilizing microplasmaWe tried to fabricate CNTs at low temperature under atmospheric pressure using a microplasma confined in small space. CNTs were successfully formed under the atmospheric pressure without substrate heating by introducing CH_4 as a raw material and Fe-containing substance as a catalyst into a microplasma in a glass capillary whose diameter is less than 100 micron. At this stage, CNTs were formed on metal wire inserted into the capillary for ignition or on inner surface of glass capillary. We are planning to improve this technique to be able to deposit CNT at any arbitrary position.We also developed a new technique, laser ablation in liquid media, for high quality nanoparticle preparation.