Coupled EM & Circuit Simulation Flow for Integrated Spiral Inductor

Abstract

At present, a practicable way to design IC custom inductors involves EM simulators that are able, for frequencies below 10GHz, to reproduce quite faithfully the behaviour of RF IC structures. The extracted model is based on lumped elements in a SPICE subcircuit format or S-parameter representation and requires no adjustment after fabrication and measurement. To help designers developing their projects, an automatic simulation flow has been implemented for the modelling of planar and multi-layer polygonal integrated inductors on silicon substrates based on the Cadence (Virtuoso)-Agilent (Momentum) environment. A computer program which extracts a physical-based model of inductor components that is suitable for circuit (ELDO) simulation has been used to evaluate the effect of variations in metallization, layout geometry, and substrate parameters upon monolithic inductor performance. Planar (2.5-D) numerical simulations (MOMENTUM) have been used to extract the S-Parameter based model. Square, octagonal, hexagonal and circular inductors could be designed and simulated. Experimental results confirm the accuracy of the flow. This flow is based on HSB3 technology developed by ST Microelectronics.