At deep submicron technologies even analog circuit layout must be done by CAD tool in order to meet DFM (design for manufacturing ) rules. These rules (due to i

At deep submicron technologies even analog circuit layout must be done by CAD tool in order to meet DFM (design for manufacturing ) rules. These rules (due to interference effects used in photolitography) are too complex for manual layout of even medium size designs within reasonable schedule. Manual layout results in lingering rule viloations and larger utilized silicone area than CAD tool output.