Investigation of Channel Impurity Impacts on Carbon Nanotube Field Effect Transistors by Self-Consistent Solution Between Poisson and Schrodinger Equations with Open Boundary Conditions

摘要

We present a study of carbon nanotube field-effect transistors (CNTFETs) at different channel impurities using a (2-D) full quantum simulation by self-consistent solution between Poisson and Schrodinger equations with open boundary conditions, within the nonequilibrium Green's function (NEGF) framework. In this paper by changing the channel impurity concentration abruptly and linearly, we have investigated some of the principal device characteristics. The simulation results show that the current ratio reduces dramatically in higher channel impurities. Threshold voltage is lower at lower channel impurities and drainconductance has a semi-quadratic behavior through variation in channel impurity. Subthreshold swing gets its minimum value at a certain value of channel concentration and drain induced barrier lowering plot has a negative slope and decreases by increasing the channel impurity. The results show that in linear channel impurity the variations in device characteristics are milder than abrupt channel impurity.