Accelerated waveform methods for parallel transient simulation of semiconductor devices

Simulating transients in semiconductor devices involves numerically solving the time-dependent drift-diffusion equations, usually in two or three space dimensions. Because of the computation cost of these simulations, methods that perform careful domain decomposition so as to exploit parallel processing have received much recent attention. In this paper, we describe using accelerated waveform relaxation (WR) to perform parallel device transient simulation using both clusters of workstations and the IBM SP-2. The accelerated WR algorithms are compared to pointwise direct and iterative methods, and it is shown that the accelerated WR method is competitive on a single processor. In addition, it is shown that with a domain decomposition chosen for rapid iterative method convergence rather than parallel efficiency, the pointwise methods parallelize poorly but the WR method achieves near linear speedup (with respect to the number of processors) on the IBM SP-2