Sensitivity computation using domain-decomposition for boundary element method based capacitance extractors

The on-going reduction of the on-chip feature size goes together with an increase of process variability. While the manufacturer is expected to improve the uniformity of its output, and the designers are expected to enhance circuit adaptability and reliability, the design tools are expected to deliver convenient and fast approaches capable of giving accurate characterizations of manufacturing tolerances. In this paper, we present an algorithm that enables an extension of 3-D capacitance extractors to generate both the nominal capacitances and their sensitivities w.r.t. all geometric parameters with only one extraction. Using the domain-decomposition technique, it is shown that sensitivities can be derived from the intermediate data of the standard capacitance extraction using the Boundary Element Method (BEM). The algorithm has been implemented in a layout-to-circuit extractor. It is shown by experiments that the additional cost for the sensitivity computation is less than 20% of the standard time consumption, essentially independent of the number of parameters.