奈米碳管(Carbon nanotubes, CNTs)具有直徑小、高長徑比(aspect ratio)與極佳的機械及電學性質，因此成為奈米科技領域中的重要材料並引起世界各國學術界的注意與進行研究。由於具有這些優異的性質，CNTs被預期有非常廣泛的應用範圍，如冷陰極場發射電子源、原子力顯微鏡(atomic force microscope, AFM)之探針、積體電路晶片中的interconnections等。為了使CNTs達到真正實用的目的，發展一簡單可有效控制CNTs形狀與型貌的製造方式是必需的，也是學術界與產業界研究的重點。成長vertical alignment之單一CNT與CNT陣列的技術已有多個實驗室開發成功，然而在有效控制CNT成長方向與成長複雜形狀CNT的技術卻沒有太多的進展。本計畫擬發展兩種方法控制奈米碳管的形狀與型貌，第一種方式：在CNTs成長完成後，利用電漿處理改變奈米碳管的形狀。藉由電漿轟擊與CNTs反應而改變碳管的應力狀態，進而造成碳管形狀的改變。第二種方式：在CNTs成長的過程中，利用改變施加電壓的大小與電場方向分別控制碳管的型態與成長方向。藉由改變陰極的形狀可調整電漿中的電場方向進而以其控制CNTs之生長方向。在本研究中，將會針對不同的成長參數(如：施加電壓的大小、氣體流量比例與壓力等)對CNTs型態的影響做探討與研究。此外，我們會嘗試結合上述所開發的製程來製作AFM之CNT探針，並展示其量測的結果。在AFM之CNT探針製作上，將發展並使用一簡易的製程來製作直徑小、高長徑比的CNT探針，預期此製程可簡化現今碳管探針繁雜的製程並可用於大量生產製作與提高良率，期能對奈米科技的提昇有所貢獻。 ; Due to its high aspect ratio geometry, excellent mechanical and electrical properties, the carbon nanotube (CNT) has been drawing significant attention worldwide as a core material for nanotechnology and expected to have various applications, such as cold field emitters, atomic force microscope (AFM) probes and the interconnection for integrated circuits. In order to make these applications practicable, simple and reliable growth techniques for the control of CNT geometries and morphologies are desired. For example, AFM probes need sharp tips and bending geometries are required for some special imaging purposes. Vertical alignment of individual CNTs and CNT arrays during their growth has been demonstrated; however, there has been much less progress towards more complicated morphologies. In this project, we will try to develop two methods to control the morphology and geometry of CNTs. The first approach is to use the post-growth plasma treatments to change the orientation of as-grown CNTs. By controlling the plasma-induced stresses and damages, the orientation of CNTs is expected to be changed. The second method is to develop an in-situ process to control the morphology and geometry of CNTs during the CNT growth stage. By engineering of the cathode geometry and control of the electric field directions within the cathode plasma sheath, the CNTs are expected to grow along the customized field lines. The effects of operational growth parameters, such as applied voltage during the PECVD growth, on morphology of CNTs will also be discussed. Besides, we expect to demonstrate the AFM images using CNT-based probes fabricated by improved methods described above. ; 研究期間 9801 ~ 9810
