An analytical-model generator for interconnect capacitances

A tool for automatically generating analytical models of interconnect capacitances is presented. It uses a partial knowledge of the flux components associated with a configuration to choose a suitable form of analytical expression, and then uses curve-fitting techniques to obtain the analytical models. For each coupled configuration, the form for the coupling capacitance is chosen based on a decomposition of the mutual flux associated with the two lines. The form for the correction capacitance of each line is decided based on a decomposition of its flux intercepted by the other line. A design-parameter-based modeling is pursued, since often it is desired to perform a large number of evaluations of a capacitance in a layout, with a fixed set of process parameters, but for varying values of design parameters. The configurations which are currently considered by this model generator are a single line, crossing lines, parallel lines on the same layer, and parallel lines on different layers (both overlapping and nonoverlapping)