What are DRC and LVS checks?

DRC (Design Rule Check) verifies that layout geometry meets manufacturing constraints: minimum width, spacing, enclosure, and area rules. Violations cause manufacturing defects. LVS (Layout Versus Schematic) verifies that layout correctly implements the intended circuit by extracting devices and connections from layout and comparing to schematic netlist. Both are essential sign-off checks before tape-out. Tools: Calibre, IC Validator, PVS. Clean DRC and LVS are mandatory for fabrication.