Morphological Characterization of Nanointerconnects Formed at the Interface of Sn Coated Multiwalled Carbon Nanotubes on an Etching Mask Patterned on a Si Substrate

Abstract

Tin-coated multiwalled carbon nanotube (SnO2/MWCNT) composites were synthesized by precipitation of SnCl2 within a CNT suspension in the first stage. An efficient dispersion technique using trifluroacetic acid (TFA) has been employed for the homogenous dispersion of Sn coated multiwalled carbon nanotubes (MWCNT) on an etching mask patterned on Si wafer using AZ 1500 as a photoresist. The MWCNT suspension was dispersed homogenously on the patterned Si wafer and the formation of nano-interconnects or nanojoints were clearly established by high-resolution transmission electron spectroscopy (HRTEM). High Resolution Transmission Electron Microscopy (HRTEM) images demonstrated that nano-interconnects formed between two MWCNTs consisted of both tetragonal Sn and orthorhombic SnO2 phase. .Elemental Sn was observed at the interface of two multiwalled carbon nanotubes by reduction of SnO2/MWCNTs under a reflow atmosphere. The interfacial interaction between the graphene layers in the carbon nanotubes and metallic Sn/oxides were also investigated. Raman spectroscopy studies established the interfacial interaction between MWCNT and the metallic Sn. The results revealed that the strong interaction between MWCNT and Sn lowered the ID/IG ratio in MWCNTs. The multiwalled carbon nanotubes were found to be well connected to each other on the patterned mask and this phenomenon could throw new light on the conductivity of carbon nanotubes in electronic circuits.