SUBTRACT: a program for the efficient evaluation of substrate parasitics in integrated circuits

Algorithms for the efficient evaluation of substrate parasitics in mixed-signal integrated circuits have been developed and incorporated in an extraction tool for substrate parasitics, SUBTRACT. Using a preprocessed, polynomial-based boundary element method, SUBTRACT enables the parasitic extraction process to be completely technology independent, allowing for fast evaluation. Additionally, techniques to accelerate the iterative solution of the resulting impedance matrix have been developed and employed to further improve the speed advantages that this method offers. The preprocessed boundary element method is more efficient than finite-difference schemes and orders of magnitude faster than general boundary element methods using a direct evaluation of Green´s function. Results of employing SUBTRACT to the design and verification of a mixed-signal A/D converter IC are described.