A Frequency-Domain Spectral-Balance Quasi-Two-Dimensional Approach for the Simulation of Nonlinear Devices and Circuits

In this paper a quasi-two-dimensional hydrodynamic physical model of a MOSFET device is presented, for computer-aided numerical simulation. Entirely developed in the frequency domain using the spectral balance technique, the model is based on the numerical solution of one-dimensional Poisson´s equation and of the first three moments of Boltzmann´s semiclassical transport equation in the longitudinal direction along the channel, self-consistently coupled to a vertical charge-control model between gate and channel. The equations are discretised in the space variable, and expanded in Fourier series in the time variable. The completely frequency-domain approach allows easy inclusion of frequency-dependent parameters of the semiconductor, especially important at very high frequencies (e.g. dielectric constant), and easy and straightforward coupling to the passive external environment. The absence of time-frequency domain transformations typical of Harmonic Balance schemes allows easy extension to multitone analysis