Impact of within-die parameter fluctuations on future maximum clock frequency distributions

The impact of parameter fluctuations on future circuit performance is evaluated by employing rigorously derived device and circuit models to calculate the critical path delay distributions resulting from die-to-die and within-die fluctuations. Utilizing these distributions with a recently derived FMAX distribution model validated by measured data, the effect of within-die fluctuations on the FMAX mean is forecast for the 180, 130, 100, 70 and 50 nm technology generations. Systematic within-die fluctuations impose the largest performance degradation resulting from parameter fluctuations. Assuming a 3σ channel length deviation of 20%, projections for the 50 nm technology generation indicate that essentially a generation of performance gain can be lost due to systematic within-die fluctuations. This analysis should encourage efforts toward tightening within-die process controls and developing circuit design methodologies that suppress the impact of within-die parameter fluctuations on circuit performance