Nanoscale FETs Simulation Based on Full-Complex-Band Structure and Self-Consistently Solved Atomic Potential

An improved simulation scheme for investigating the performance of nanoscale FETs is developed in this paper. The total current of the MOSFET consists of two main components: thermionic current above the top of barrier of the channel calculated by ballistic approach and tunneling current computed by Wentzel-Kramer-Brillouoin approximation based on a full-complex-band structure. Furthermore, to get atomic-position-based potential profile in the nanoscale device, we self-consistently solve atomic charges and potentials in the real space along and transverse in the transport direction. The device performance calculated with this model shows excellent agreement with that obtained using non-equilibrium Green's function solver (full quantum mechanism) but by using only one-tenth of the simulation resource. Moreover, special characteristics of insulating materials integrated with advanced device structures can also be incorporated in this Poisson solver. An example based on the negative capacitance MOSFET is examined with this model, and it shows significantly improved performance than conventional MOSFET.