High order explicit versus quasi-linear implicit finite-difference approximation for semiconductor device time-domain macroscopic modelling on parallel computer

Bipolar semiconductor device 2D FDTD modelling suited to parallel computing is investigated in this paper. The performance of a second order explicit approximation, namely the Nessyahu-Tadmor scheme (NT2) associated with the decomposition domain method, are compared to a classical quasi-linear implicit one based on the Alternating Direction Implicit method (ADI). The comparison is performed both from the numerical stability point of view by means of drift-diffusion and energy-momentum simulations and from the computation efficiency point of view. The test structure is a millimetre-wave IMPATT diode the RF as well as internal operation of which is highly non linear. The results demonstrate that high order explicit approximations compete with implicit approximations and allow the development of efficient models well suited to the parallel computation.