Accuracy Controlled Direct Integral Equation Solver of Linear Complexity with Change of Basis for Large-Scale Interconnect Extraction

In this paper, we develop a new linear-complexity direct solver for large-scale integral equation based interconnect extraction. The new solver possesses not only explicitly controlled accuracy, but also a change of cluster basis to efficiently account for the updates to the original matrix during the direct solution procedure. Comparisons with state-of-the-art direct solvers have demonstrated a much reduced CPU run time of the new solver as well as a significantly improved accuracy, which is also well controlled. Rapid and accurate direct solutions of millions of unknowns have been obtained on a single CPU core.