o Variability Management: Use advanced modeling (AOCV/POCV) and variation-aware design techniques. Statistical timing and yield analysis become crucial.
o Complex Design Rules: multi-patterning rules (coloring, masks), pitch restrictions, via rules, and DFM (Design for Manufacturability) requirements like dummy fill, via ladders, etc.
o Power Integrity: Aggressive power grid design (dense mesh), extensive use of decap cells, careful IR drop and EM analysis (static and dynamic) are mandatory. Lower voltage margins make designs very sensitive.
o Signal Integrity (SI):
o Placement Density:
o Lithography: Account for litho hotspots and limitations (e.g., tip-to-tip spacing, EOL rules).