Abstract
Carbon nanotube (CNT) is expected to use as the materials of nano-scale components of electronic devices. In this study, we investigated the damage mechanism of Multi-walled (MW) CNT structures used as nano-component of electronic devices. An acceleration testing system of direct current loading was designed and the test structures collected MWCNT at the gap of Pt thin-film electrodes were treated in the system. The damage mechanisms of MWCNT are regarded as the effects of oxidation by Joule heating and/or the electromigration (EM) by high-density electron flows. Therefore the tests were conducted under the two kinds of current density and temperature conditions, and furthermore in both of air and low oxygen conditions. Lifetime of the specimen was determined by voltage measurements during the acceleration tests under the constant current condition. Their fracture phenomena were evaluated by means of microscopic observations. As the results, the amounts of lifetime of MWCNT were longer in the lower oxygen concentrations than in the air condition. In the microscopic studies, it was confirmed that the disconnections of MWCNT were occurred at the cathode side of the MWCNT structures under low current density, and the center area of MWCNT under high current density. Both types of damage morphologies induced by oxidation and EM were observed at the damaged MWCNT.
