Simulation of semiconductor transport using coupled and decoupled solution techniques

Abstract Two dimensional mobile carrier transport in a semiconductor is simulated using the finite element method. Two algorithms are compared for computational efficiency and accuracy in modeling an IGFET transistor. With the first, the non-linear partial differential equations are decoupled and solved sequentially using a minor and a major iterative cycle. In the second, Newton's method is used to linearize the equations, and they are solved simultaneously using only a major loop. Results show the decoupled approach to be faster and require less storage than the coupled Newton approach for simulation of device operation where the mobile carrier densities are equal to or less than the fixed charge density. The coupled approach is more efficient for highly non-linear problems where the mobile carrier densities exceed the fixed charge density but requires far more storage (2.5x) and set up time (100x).