Modeling And Characterization Of Novel Interconnects For3-D ICs

"Moore’s Law" has been highly recognized as one rule for the development of integrated circuits (ICs) for many years.With the scaling down of feature size, the delay of interconnect has exceeded the gate delay and moved to the forefront as the limiting factor in IC performance, which implies that ICs have entered the "interconnect-era". Therefore, the interconnect design for next-generation ICs has attracted much attention in recent years. In this dissertation, several types of novel interconnects, i.e. carbon-based nano-interconnect and through-silicon via (TSV), etc., are modeled and investigated in detail. The main academic contribution of this dissertation is summarized as follows.1) The energy band structure of graphene is analyzed, and the number of conducting channels and mean free path (MFP) of graphene nanoribbon (GNR) are calculated. Further, the numbers of conducting channels for different GNRs are obtained and expressed by a set of analytical equations, with the quantum contact and scattering resistances calculated.2) The multi-conductor transmission line model for multilayer graphene nanoribbon (MLGNR) is simplified to an equivalent single-conductor (ESC) one. The analytical equations for quantum capacitance and kinetic inductance are presented, and compared with those of multi-walled carbon nanotubes (MWCNT). Based on the ESC model, the equivalent resistivity, time delay, and crosstalk of MLGNR are characterized in detail.3) The equivalent circuit model of through-silicon via (TSV) is established, with its frequency, temperature, and MOS effects taken into account. Also, the impacts of physical and geometrical parameters on its transmission performance are studied.4) The electromagnetic couplings in high-density TSV arrays are investigated, with one typical3-TSV array taken for example. Considering the inductive, capacitive couplings and screening effect, its effective conductance and capacitance are examined analytically.5) The model of coaxial TSV is proposed and studied so as to solve the electromagnetic couplings in the TSV arrays. Its equivalent circuit model is simplified, with the MOS capacitance considered. It is found that with the implementation of BCB material, the transmission performance of coaxial TSV can be improved greatly, but the power handling capability (PHC) will be degraded.6) Utilizing the CNT bundle, both electrical and thermal performances of TSVs can be improved significantly. Further, the transmission-line method (TLM) is employed to study the CNT-based TSVs, and the noise voltage responses can be captured accurately. In addition, the model of MWCNT-based on-chip capacitors are studied, with the impacts of geometrical parameters examined in detail. Finally, a novel thermal management structure, i.e. CNT-based thermal TSV and giaphene layer, is proposed to conduct the heat to the bottom heat sink. It is believed that this structure is an efficient solution for thermal management of3-D ICs.