Additive Decomposition Applied to the Semiconductor Drift-Diffusion Model

A new numerical method for semiconductor device simulation is presented. The additivedecomposition method has been successfully applied to Burgers' and Navier-Stokesequations governing turbulent fluid flow by decomposing the equations into large-scaleand small-scale parts without averaging. The additive decomposition (AD) technique iswell suited to problems with a large range of time and/or space scales, for example,thermal-electrical simulation of power semiconductor devices with large physical size.Furthermore, AD adds a level of parallelization for improved computational efficiency.The new numerical technique has been tested on the 1-D drift-diffusion model of a p-i-ndiode for reverse and forward biases. Distributions of φ, n and p have been calculated using the AD method on a coarse large-scale grid and then in parallel small-scale gridsections. The AD results agreed well with the results obtained with a traditional one-gridapproach, while potentially reducing memory requirements with the new method