A PARALLEL-IN-TIME METHOD FOR THE TRANSIENT SIMULATION OF SOI DEVICESWITH DRAIN CURRENT OVERSHOOTS

This paper presents a new parallel-in-time algorithm for the two-dimen sional transient simulation of SOI devices. With this approach, simula tion in both space and time domains is performed in parallel. As a res ult, the CPU time is reduced significantly from the conventional seria l-in-time method. This new approach fully exploits the inherent parall elism of the finite-difference formulation of the basic semiconductor device equations and the massively parallel architecture of SIMD compu ters. The space domain computations are inherently parallel due to the nature of our technique of solving the finite-difference equations. T ime domain parallelism is achieved by shifting the potentials from pre vious time points to subsequent points one-step forward along the time axis with each Gummel iteration. This algorithm employs a fixed-point iteration technique, therefore a direct solution of matrix equations is avoided. The algorithm is especially suitable for the transient sim ulation of SOI devices that exhibit transient drain current overshoot. Numerical experiments show that the new parallel-in-time method is up to eight times faster than the conventional serial-in-time method in SOI transient simulations. The program is coded in CM Fortran for the Connection Machine.