Lateral interactions between standard cells using pattern matching

This paper proposes a novel method of identifying interactions between neighboring standard cells via fast-CAD pattern matching. Studies of cell-to-cell interactions for both metal 1 and poly layouts are made for selected samples from libraries for 130 and 90 nm generations provided under an NDA agreement by ST Microelectronics. Both simulation and pattern matching are utilized to identify and quantify hot-spots. The physical basis for pattern matching is described. In validating pattern matching compared to full simulation, changes in linewidth for a fixed defocus setting varied quadratically with pattern match factor and can be modeled by a parabolic equation with an r-squared value of 0.77. Results demonstrate that there is a considerable best-to-worst variation of 4-7% in the linewidth among neighbors, which is produced through a focus swing of 0.58 Rayleigh Units (RU). The focus swing is oscillatory with cell separation distance, and a slight shift in spacing on the order of 0.5 λ /NA can mitigate lateral interaction effects.