Growth of High Quality Carbon Nanotubes on Free Standing Diamond Substrates

摘要

Carbon nanotubes (CNTs) were grown on diamond-coated Si substrates and free-standing diamond wafers to develop efficient thermal interface materials for thermal management applications. High quality, translucent, free- standing diamond substrates were processed in a 5 kW microwave plasma chemical vapor deposition (CVD) system using CH4 as precursor. Ni and Ni-9%W-1.5% Fe catalyst islands were deposited to nucleate CNTs directly onto the diamond substrates. Randomly-oriented multi-walled CNTs forming a mat of tilde 5 micrometers thickness and consisting of tilde 20 nm diameter tubes were observed to grow in a thermal CVD system using C(2)H(2) as precursor. Transmission electron microscopy and Raman analyses confirmed the presence of high quality CNTs on diamond showing a D/G peak ratio of 0.2-0.3 in Raman spectra.