Fast 3D electrostatic simulations are of increasing importance in the area of VLSI interconnects and MEMS, especially for the current deep submicron semiconductor technology. The parasitic capacitance among the interconnects is usually simulated within a finite domain with the mixed Neumann and Dirichlet boundaries. The boundary element method (BEM) is very suitable for such kind of electrostatic computation. Furthermore, a new technology called quasi-multiple medium (QMM) method has been proposed to accelerate the large-scale BEM computation. The QMM technology has been applied to the 3D finite-domain BEM simulation of the interconnect capacitor, and it greatly reduced the computational time and memory usage. In this paper, an approach is presented to enhance the QMM technology, in which the QMM cutting number is automatically selected before decomposing original medium regions into more fictitious medium blocks. With this approach, a reasonable parameter (m, n) is found to make the QMM technology achieve higher computational speed. Besides, the assembly of the global system of linear equations and a new preconditioner for the GMRES solution of the global linear system are introduced. The enhanced QMM technology makes the 3D finite-domain electrostatic computation much faster, while preserving high accuracy.
