Research On Crosstalk Problems Of Carbon Nanotube Interconnects

ITRS forecasted that, with feature size of integrated circuit decreases gradually, theresistivity of copper wire will increase rapidly due to scattering by electron surface and grainboundary, which will bring a range of issues such as delay and crosstalk problems, carbonnanotube is considered one of the ideal interconnect material to replace copper in future. Sofar, the preparation of carbon nanotube has made great progress, however, carbon nanotubeinterconnect integration technology is not successful breakthrough, some researchers aredoing the research about modeling, especially the crosstalk problems of carbon nanotubeinterconnect is one of the hot spots in the current study. In order to achieve carbon nanotubefor integrated circuit interconnect in the future, it is a very important issue to study crosstalkproblems of signal integrity by modeling carbon nanotube interconnect.Based on distributed parameter transmission line model, the main parameters such asresister, capacitance and inductance of single-walled carbon nanotube (SWCNT) interconnectand double-walled carbon nanotube (DWCNT) interconnect are extracted first. In order topredict crosstalk characteristics of carbon nanotube interconnect under high frequency moreaccurately, we extract the magnetic inductance of carbon nanotube bundle by usingelectromagnetic analysis software, the existing model of carbon nanotube is improved.On the basis of accurately extracting the magnetic inductance of carbon nanotube bundle,crosstalk voltage is used as the main evaluation index, then single-walled carbon nanotubeinterconnect and double-walled carbon nanotube interconnect are discussed separately fromchange of the length, spacing, frequency, and discussed the change in relative position ofinterconnect for the first time. From the results of the simulation, it is observed that thecrosstalk can be reduced by decreasing the length of carbon nanotube, increasing the linespacing, choosing the suitable relative position or appropriate signal frequency. In addition,comparison of performance is made between carbon nanotube and Cu, we find that theperformances of SWCNT bundle interconnect and DWCNT bundle interconnect improveobviously in the intermediate level and the global level.The work has discussed about the circuit performance of carbon nanotube as futureinterconnect, especially about crosstalk characteristics. The results obtained have somesignificance to carbon nanotube interconnects design and analysis for future, and also providesome guidance to the growth of carbon nanotube interconnect and carbon nanotubeapplication.