||The dramatic scaling of the integrated circuit technology leads to significant challenges for Cu interconnects. The increasing Cu resistivity due to the size effect causes the unacceptable signal transmission delay. The increasing current density further aggravates the electromigration (EM) of the Cu interconnect. Carbon nanotube (CNT) is considered an alternative material to Cu interconnect, in terms of bottom-up growth process, high electrical and thermal conductivity and high EM resistance. Using a PECVD system, we studied the effects of catalyst thickness, barrier layer, gas composition and built-in electric-field in plasma to control the location, diameter, density, structure, composition and orientation of the CNTs. We demonstrated a low temperature transfer of the vertically aligned CNT film using liftoff technique to avoid the high temperature during the CNT growth process. We fabricated Cu/CNT composite by combining CNT growth and Cu electroplating to solve some engineering problems of the CNT fabrication. We demonstrated the integration of CNT as the contact plug to the silicon MOSFET. The silicide-rooted and open-ended CNT contact plug exhibited better electrical conductivity and thermal stability than the conventional W contact plug. We also demonstrated Cu/CNT composite for via filling to connect two metal layers, exhibiting comparable resistivity to Cu via. We studied the current carrying capacity and the electrical breakdown of the CNT. We investigated the EM properties of Cu/CNT composite via using Kelvin structure, exhibiting much longer EM lifetime than Cu via only. We also studied the EM properties of Cu/CNT composite using the conventional Blech structure. The results suggest that Cu/CNT composite is a potentially good candidate for advanced interconnect applications where high current density and good EM resistance are required.