3-D perpendicular assembly of SWNTs for CMOS interconnects

Due to their superior electrical properties such as high current density and ballistic transport, carbon nanotubes (CNT) are considered as a potential candidate for future very large scale integration (VLSI) interconnects. However, direct incorporation of CNTs into a complimentary metal oxide semiconductor (CMOS) architecture by the conventional chemical vapor deposition (CVD) growth method is problematic because it requires high temperatures that might damage insulators and doped semiconductors in the underlying CMOS circuits. In this paper, we present a directed assembly method to assemble aligned CNTs into pre-patterned vias perpendicular to the substrate. A dynamic electric field with a static offset is applied to provide the force needed for directing the SWNT assembly. It is also shown that by adjusting assembly parameters the density of the assembled CNTs can be significantly enhanced. This highly scalable directed assembly method is conducted at room temperature and pressure and is accomplished in a few minutes. I-V characterization of the assembled CNTs was conducted using a Zyvex nanomanipulator in a scanning electron microscope (SEM) and the measured value of the resistance was 270 k Omega s.