Computationally Efficient Multiple-Independent-Gate Device Model

Abstract

Abstract-Nanowire Field Effect Transistors (FETs) with multiple independent gates around a silicon channel feature ultimate gate control and are regarded as promising candidates for next generation transistors. Being inherently more complex than conventional gate-all-around nanowire FETs, they require longer simulation times, especially with numerical simulations. We present a new model enabling the efficient computation of voltages and current in modular semiconductor structures with an arbitrary number of independent gate regions. Its validity extends on Gate-All-Around MOSFETs, FinFETs and gate-less channels. It exploits existing models for conventional devices and builds results on top of these. Being completely general, the method is independent from the models used to describe each region, a charge-based model in our case. Applied to a multiindependent-gate nanowire FET structure, extensive comparison of the proposed method with results from physics-based TCAD Atlas software and with numerical exact results show very good agreement with relative errors of less than 1.8% for potentials and less than 4% for currents, under a broad variations of physical parameters as well as biasing conditions. Interpreted language implementation shows a performance advantage in excess of one order of magnitude with respect to standard optimized numerical methods, still providing excellent accuracy, and making it suitable for implementation in circuit simulators.

Drain Current Model of One-Dimensional Ballistic Reconfigurable Transistors

“…The reason is that the analytical expression for the drain current corresponding to the thermionic emission with a shifted Fermi level and including energy-independent transmission can be used at small bias, when the contribution of thermally excited electrons in the total current is large enough [24]. The analytical current calculations on the basis of drift-diffusion model do not properly take into account the effect of SB tunneling and BTBT on the electron transport [25], [26]. The empirical continuous compact dc model based on a set of empirical fitting parameters is reliable in the framework of experimental data [27], but it cannot be used for predictions.…”