Calculation of multiterminal resistances in integrated circuits

A method has been developed for calculating the node admittance matrix of integrated resistors. It is based on a discretization of the conductor through a nonuniform rectangular grid of cells, that can be adjusted precisely to the boundary of any conductor with orthogonal edges. These cells are modeled by a number of lumped resistors, for which expressions have been obtained from the finite-difference approximation of Laplace´s equation. The solution of the resistive network generated in the discretization stage is carried out through a special algorithm that performs a partial step by step construction of the admittance matrix ´of the network by eliminating an internal node in each step and obtaining the equivalent network. Comparing the results of this method with those of other commonly used methods for solving this problem, the advantageous features of our method are made clear.