Hetero-junction carbon nanotube FET with lightly doped drain and source regions

In this paper, a new structure was introduced for carbon nanotube (CNT) MOSFET transistors. The proposed structure was composed of two different nanotubes for the source/drain and channel regions. Electrical characteristics of this structure were investigated using nonequilibrium Green's function approach. Results of the simulations demonstrated that the proposed hetero-structure had almost the same ON-current and much less OFF-current and as a result higher I-ON/I-OFF ratio than the conventional homo-structure. Results of the comparison between switching behavior in equal I-ON/I-OFF ratio showed that, although the proposed structure had longer delay, its power dissipation for every switching event was less than that of the conventional structure. A further comparison of the switching characteristic in equal ON-current values showed that the proposed structure enjoys from shorter delay and also consumes less power-delay product (PDP) when compared to the LDDS structure.