Novel selective process via self-assembled monolayers for pattern growth of carbon nanotubes by MP-CVD

• Main Authors: De-Shan Kuo, 郭得山
• Other Authors: Cheng-Tzu Kuo
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/69594151918195813470

碩士 === 國立交通大學 === 材料科學與工程系 === 91 === The well controllable selective growth of carbon nanotubes (CNTs) on the desired area is an important issue for their future applications. In this study, a novel method for selective growth of CNTs was proposed by using the technologies of self-assembled monolayers (SAMs) and the Fe-assisted CNTs growth. The Si wafers with the a:Si/Si3N4 layer patterns were first prepared by low pressure chemical vapor deposition (LPCVD) and lithography techniques to act as the substrates for selective deposition of SAMs. The selectivity of SAMs from APTMS solution (N-(2-aminoethyl)-3-aminopropyltrimethoxsilane) is based on its greater reactivity of head group on a:Si than Si3N4 films. The areas of pattern with SAMs will first chelate the Fe3+ ions by their diamine-terminated group. The Fe3+ ions were then consolidated to become Fe-hydroxides in sodium boron hydride solution to form the Fe-hydroxides pattern. Finally, the Fe-hydroxides pattern was pretreated in H plasma to become a well-distributed Fe nano-particles on the surface, and followed by CNTs deposition using Fe as catalyst in a microwave plasma-chemical vapor deposition (MP-CVD) system to become the CNTs pattern. The products in each processing step, including SAMs, Fe-hydroxides and CNTs, were characterized by contact angle measurements, scanning electron microscopy (SEM), Raman, XPS, Auger spectroscopy, transmission electron microscopy (TEM) and high resolution TEM (HRTEM). The results show that the main process parameters include the surface activation process and its atmosphere, consolidation time and temperature, H plasma pretreatment. The function of each processing step will be discussed.