Effect of Oxygen Concentration on Damage Mechanism of Carbon Nanotubes Under High Current Density

Abstract

Multi-walled Carbon nanotube (MWCNT) has a great tolerance to electromigration (EM). Therefore, MWCNT is expected to be applied to via-material of electronic devices. But, the damage mechanism of MWCNT has not yet been revealed though oxidation by Joule heating and the EM by high density electron flow are proposed as causes of the MWCNT damage under high current density. In this study, we performed acceleration tests of MWCNT to reveal the damage mechanism of MWCNT under high current density. As a result of the acceleration test, lifetime in low vacuum condition with a low oxygen concentration was longer than that in the air. And, local evaporation of carbon due to oxidation appeared near the cathode end of CNT under both conditions. We confirmed presence of two mechanisms of CNT damage; oxidation and EM. It was shown that the oxidation mechanism at the damage site due to EM was enhanced under oxygen rich condition.