High-frequency interconnect modeling for global signal networks

In this work, a systematic analysis of the transmission line models used for high-frequency global interconnection lines is presented. As part of this analysis, two model implementations are carried out using: i) the technology parameters provided by the manufacturer, and ii) the scattering (S_ij) parameters associated with a transmission line. In order to serve as test vehicles, a chain of inverters and several ring oscillators with lines of width w_i = 2 mum and length l_i = 1.0 to 3.0 mm were implemented using an Austria miscrosystems 0.35 mum process technology and a power supply of 3.3 V. The simulation results using the equivalent model obtained from S-parameters show the lowest average error when they are compared with post layout simulations. In addition, the obtained results show that the total delay in a chain on three inverters is increased up to 120% and the operation frequency of ring oscillator is reduced up to 58.8% when long interconnections (l_i = 3 mm) are used.