Standard cells having transistors annotated for gate-length biasing

Abstract

Methods, layouts and chip design layouts that use annotations for communicating gate-length biasing amounts to post-layout tools are disclosed. One method includes receiving a chip design layout designed to includes select ones of a plurality of nominal cell layouts and an annotated cell layout. The chip design layout is defined by a plurality of layers and the plurality of nominal cell layouts define transistors, wherein each of the plurality of nominal cell layouts define nominal length transistors, and the annotated cell layout also defines transistors. The annotated cell layout is associated with an annotation layer that identifies a gate-length biasing to be applied to at least one transistor of the annotated cell layout. The gate-length biasing identifies an amount of change for a gate length and not width-sizing of a gate width of the at least one transistor of the annotated cell layout. The annotation layer is used to communicate design-specific directives that require implementation. The method uses a processor to process the chip design layout, with reference to the annotation layer, to apply the gate-length biasing to the annotated cell of the chip design layout.