Abstract
To investigate the feasibility of nanocarbon interconnects for future LSIs, the electrical resistance of exfoliated multilayer graphene (MLG) wirings has been studied with accurate measurements of the number of layers. We employed transmission electron microscopy (TEM) as an exact number determination method, atomic force microscopy (AFM) as a simple method, and an extended optical contrast method as an easy distinction method, which we proposed for determining the number of layers. The sheet resistance of MLG wirings, including TEM determined 3-, 54-, and 341-layer MLGs, has been measured using the four-probe method and the layer number dependence of sheet resistance was discussed on the basis of a ladder circuit model simulation. It is shown that the dependence agrees well with the simulations, suggesting parallel conduction in MLG wirings, even if the probe electrodes are deposited just on the top layer of MLG.