Interconnects and Propagation of High Frequency Signals

Abstract

In deep submicron ULSI designs, the overall circuit behavior is significantly determined by the on-chip interconnect structure. Until recently, most interconnect models took only capacitances and resistances into account. Due to the steady increase in device speed, integrated circuits will behave more and more like microwave circuits. With operating frequencies in the GHz regime, the effect of the magnetic field can no longer be neglected. Inductances, the skin effect, and transmission line behavior have to be considered carefully. Therefore, several advanced parameter extraction methods have been established. For complicated interconnect topographies, where lumped or one-dimensional distributed models do not reach the required accuracy, three-dimensional quasistatic or even full-wave models are required. These methods generate huge equation systems that cannot be used directly for circuit simulation. To increase efficiency, model order reduction techniques become necessary. Since the amount of power dissipated in the interconnect structures is increasing, thermal interconnect modeling is also gaining importance, especially for Silicon-On-Insulator chips and low-k materials. We will analyze the impact on circuit design and discuss the requirements for simulation software to keep pace with these demands.