Synthesis of Carbon Nanotubes (CNTs) as Thermal Interface Material

Abstract

Carbon nanotubes (CNTs) are promising materials for many potential applications. High electrical conductivity, superior mechanical strength, thermal conductivity, and chemical inertness are some of the properties of CNTs. CNTs can carry high – current densities, and they have been studied as cold – cathode field emitters. Small diameter and relatively long length of CNTs makes them perfect field emitters with high emission currents at low electric fields. In this thesis, electrical and thermal properties of CNTs considered. For this, selective and non – selective multi – wall carbon nanotubes (MWCNTs) are synthesized by Chemical Vapor Deposition (CVD) method. CNTs are synthesized on both Nickel (Ni) and Silicon (Si) substrates. In some cases, SiO2 under layer is employed on silicon wafer. Iron (Fe), Nickel (Ni), and Carbon (C) are used as catalyst types onto Si and SiO2 coated Si substrates. The SEM images, growth conditions and their effects such as catalyst thicknesses, DC/RF sputtering distance, sputtering pressure, gas flow rate, and CVD temperature effects are discussed. The patterned CNT fabrication process is also studied in this thesis.