Carbon nanotube–carbon nanotube contacts as an alternative towards low resistance horizontal interconnects

Abstract

We propose to use carbon nanotube (CNT)–CNT contacts instead of CNT–metal contacts as a route towards low resistance CNT horizontal interconnects. We characterize by electrical transport measurements and Kelvin probe force microscopy the contacts present in CNT horizontal interconnects grown by chemical vapor deposition between titanium nitride electrodes. When two CNTs with diameter around 30 nm grow from opposing electrodes and touch each other with their outermost shells, typical contact resistances around 16 kΩ are obtained. The corresponding contact resistivity of about 14 Ω μm 2 is one order of magnitude smaller than the contact resistivity of a CNT touching the TiN surface with its outermost shell. On the other hand, the contact resistance of a CNT grown from a nickel catalyst particle deposited on a TiN electrode is negligibly small when compared to the above mentioned contact resistances. Our results demonstrate that we are able to grow from opposing electrodes CNTs that touch each other with a corresponding high density (up to 10 11 cm −2) of CNT–CNT contacts. This may offer an effective solution towards the growth of low resistance CNT horizontal interconnects.