Electrical modeling of carbon nanotube-based shielded through-silicon vias for three-dimensional integrated circuits

摘要

In this article, two kinds of shielded carbon nanotube (CNT) through-silicon vias (TSV) are proposed and investigated for high-density three-dimensional integrated circuits (3-D ICs). First, vertical aligned CNT array is inserted into a single hole, and two isolated metal pads, that is, the central circular and outer annular pads, are deposited onto the surface to make distinct conduction paths. The shielded CNT TSV, which can also be named as coaxial TSV, is formed, with the semiconducting CNTs utilized to suppress lateral conductance. Based on a similar concept, the shielded differential CNT TSV is developed. By virtue of the proposed shielded CNT TSVs, the chip area can be saved significantly. The equivalent circuit models are established for the proposed shielded CNT TSVs. A passive equalizer is designed to improve the signal quality for shielded differential CNT TSV. Finally, the potential applications of the proposed TSVs in 3-D IC power distribution network design are investigated.