氮在化學汽相沉積法成長具方向性奈米碳管中扮演的角色

The role of nitrogen in the formation carbon nanotubes by CVD.

潘嗣文(Ssu-Wen Pan)

指導教授 ： 賴再興

中原大學/理學院/應用物理研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500276

摘要

我們以熱化學汽相沉積法(Thermal CVD)來成長具方向性的奈米碳管(Carbon Nanotubes,CNTs)。我們選用甲烷為碳源，鎳為催化劑，分別以二氧化矽及氮化矽為緩衝層的矽為基板，利用氨氣對基板做前處理(pretreatment )後，在不同的成長參數下，成功地合成出具有良好方向性的奈米碳管。我們利用掃描式電子顯微鏡(SEM)、穿透式電子顯微鏡(TEM)及能量分散式X射線分析儀(EDX)對成長出的奈米碳管做結構和成分分析。我們發現，經前處理後基板上的催化劑顆粒以及所成長的奈米碳管中，均有氮原子的摻雜，所以，氮原子在整個製程中所扮演的角色，不僅在前處理階段對催化劑的蝕刻有影響，更近一步地，摻雜到我們的產物之中，且能幫助CNTs進行具方向性的成長。
我們也整合了奈米球顯影術來處理基板表面，讓基板表面上的催化劑顆粒分的夠開，因而降低了所成長CNTs的密度，然而，相對的CNTs的方向性也變差了。

關鍵字

二氧化矽 ； 氮化矽 ； 奈米碳管 ； 甲烷 ； 化學汽相沉積法 ； 氨

並列摘要

Abstract
Well-aligned carbon nanotubes(CNTs) were synthesized by thermal CVD. CH4 was chosen as our carbon source, Ni as our catalyst and Silicon, with buffer layer SiO2 or Si3N4, as our substrates. After the pretreatment of the substrate proceeded by NH3, CNTs with good alignment were then prepared under optimal growth conditions. The grown CNTs were characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray analysis ( EDX). We observed that nitrogen atom could be found both in the pretreated catalytic particles and in the synthesized CNTs. Therefore, we conclude that nitrogen atom not only plays a role in etching the catalytic particles during the pretreatment, but also, but also plays a role in helping the alignment of our grown CNTs via its doping into the samples.
Finally, in order to reducing the density of CNTs, we applied the nanosphere technique to our substrates to increase the separation between the catalytic particles. We do obtained CNTs with reducing density, but we also pay the price of deteriorating the alignment of the CNTs.

並列關鍵字

NH3 ； SiO2 ； Si3N4 ； CH4 ； carbon nanotubes(CNTs)

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