Metal zero power ground stub route to reduce cell area and improve cell placement at the chip level

Abstract

A system and method for laying out power grid connections for standard cells are described. In various embodiments, a standard cell includes power post and ground posts in metal zero. The metal zero posts include no vias to any upper metal layers. Some variations of the standard cell have the power and ground posts routed in metal zero to a boundary edge of the standard cell. Layout rules are changed to allow this type of routing. The power and ground posts in metal zero are connected to power and ground posts in metal zero of a neighboring cell by abutment. The place-and-route tool doesn't need to perform a further routing step after placing the cells. For other variations, the power and ground posts are not routed to the boundary edge and the place-and-route tool routes power and ground connections in metal zero between the standard cell and the neighbor cell.

Dependencies are inferred from the claim text.