Simulation of a carbon nanotube field effect transistorwith two dierent gate insulators

In this paper, a novel structure for MOSFET like CNTFETs (MOSCNTs) is proposed, combining the advantages of both high and low dielectrics to improve output characteristics. In this structure, the gate dielectric at the drain side is selected from a material with low dielectric constant to form smaller capacitances, while a material with high dielectric constant is selected at the source side to improve on current and reduce leakage current. The new structure is simulated based on the Schrodinger-Poisson formulation. Obtained results show that the proposed conguration has lower o and higher on current in comparison with low-k MOSCNTs. Also, using a two-dimensional model, a wide range of new structure performance parameters is studied. It is found that transconductance, intrinsic cut-o frequency and quantum capacitance parameters are improved compared to MOSCNTs with low dielectric constant. It is clear that the proposed structure can provide DIBL and subthreshold swing near its theoretical limit, while it also prots from smaller capacitances in gate, drain and source in comparison with high-k MOSCNTs.