Accurate interconnect modeling for high frequency LSI/VLSI circuits and systems

Criteria and methods for accurately modeling LSI/VLSI interconnect lines at various high-frequency ranges are discussed. The Elmore-Sakurai RC model for delay time is verified for frequencies of tens to low hundreds of MHz. The inductance effect is then analyzed for frequencies from high tens to low hundreds of MHz to 50 GHz. General and special transfer functions are analyzed and plotted. The skin-effect-caused frequency dependence of line resistance and inductance are considered. Finally, the impulse response function is derived from inverting the transfer function, and simplified for efficient computerisation of the transient response of an interconnect line at very high frequencies. The models are verified to the exact fit using a network analyzer and digitizing oscilloscope in a magnetically and electrically shielded environment, measuring the S-parameters (amplitude of transfer function), phase, and transient responses.<>