Coupling computation of the BEM and FDM in 3D capacitance extraction

When using the boundary element method (BEM) to calculate the capacitance of three-dimensional VLSI interconnects with multiple dielectrics, a significant error can occur if some dielectrics do not contain a conductor. We present a new algorithm of coupling computation of BEM and the finite difference method (FDM) to resolve the problem. This algorithm still uses BEM for dielectrics which contain conductors, but employs FDM for those without. Then we couple these equations to calculate the capacitance. The numerical results indicate that this algorithm reduces calculation error greatly.