The purpose of this study is to investigate the effect of carbon nanotube (CNT) growth parameters on CNT via resistance and examine the transverse motion of electrons in the CNT bundle vias. Single vias of 3.85x3.85 and 2.45x2.45 mu m(2) correspond to 0.35x0.35 mu m(2) 6x6 and 4x4 array vias, respectively. With nickel catalyst, CNTs were grown by microwave plasma-enhanced chemical vapor deposition method. Two-terminal CNT via chains of single via and array vias were fabricated on the tantalum metal electrodes. The increase in pretreatment power or substrate temperature resulted in the decrease in CNT diameters and thus the increase in CNT packing density due to the etching effect of exciting hydrogen. This led to the decrease in CNT via resistance owing to more conducting channels. The increase in growth power or substrate temperature enhanced the CNT graphitization and hence yielded the decrease in CNT resistances as well as CNT via resistances. In the same via area, the CNT via resistance of array vias is lower than that of a single via. This could be ascribed to less tube-tube junctions and thus lower electrical resistance in the array vias. Accordingly, the transverse motion of electrons in the CNT bundle vias was demonstrated. Therefore, the integration of CNT array vias with CNT bundles is proposed for optimizing the conductivity of CNT vias in the global interconnects where the via dimensions are more alleviated.
