Well-aligned Carbon Nanotubes Synthesis on Porous Silicon by Electroless Plated Pd and Microwave Enhanced Chemical Vapor Deposition

• Main Authors: Chi-wei Chao, 趙志偉
• Other Authors: H.C. Shih
• Format: Others
• Language: en_US
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/06302495104609888290

碩士 === 國立清華大學 === 材料科學工程學系 === 87 === We propose a method to synthesize aligned carbon nanotubes on selected-area silicon in one step by microwave plasma ehance chemical vapor deposition (MPECVD) system with a mixture of methane and hydrogen as precursors and applied DC bias.The pretreatment of selected-area substrate: anodizing technology and electroless plating Pd as catalytic particles.The advantages of MPECVD are low deposition temperature and short deposition time comparing to the conventional CVD. Synthesizing carbon nanotubes by MPECVD takes about 12minutes ~ 30 minutes and the deposition temperature are about 500 ~ 650 ℃. The well-aligned carbon nanotubes were analyzed by the following technique: Scanning electron microcopy (SEM), High-resolution transmission microscopy (HRTEM), Raman spectroscopy and X-ray diffraction (XRD). The diameter of carbon nanotubes are about 60nm ~ 100nm. We changed the concentration of hydrogen to synthesize different morphologies of carbon nanotubes and applied DC bias increasing etching rate of random-direction carbon nanotubes. We find that the shapes and nature of catalyst particles are key to control the morphology and structure of carbon nanotubes. We also proposed some growth mechanisms of carbon nanotubes.