Software and method for via spacing in a semiconductor device

A computer-readable software product for executing a method of determining the location of a plurality of power rail vias in a semiconductor device, wherein the semiconductor device includes an active region and a power rail, wherein the power rail includes the power rail vias, the method comprising:

• assigning a location of a first power rail via along the power rail;
• assigning a location of a second power rail via along the power rail, wherein a spacing between the location of the first power rail via and the location of the second power rail via is a minimum spacing allowable;
• determining the spacing between the location of the second power rail via and the locations of structures in the active region which may electrically interfere with the second power rail via;
• and
• changing the location of the second power rail via in response to the spacing between the location of the second power rail via and the location of one of the structures in the active region being less than a predetermined distance.

A method of fabricating a semiconductor device, comprising

• forming a plurality of transistors in an active region of a substrate;
• determining a location of a power rail to supply electrical power;
• determining locations of a plurality of power rail vias to couple the power rail to the transistors, wherein determining the locations of the power rail vias includes:
• assigning a location of a first power rail via along the power rail,
• assigning a location of a second power rail via along the power rail, wherein a spacing between the location of the first power rail via and the location of the second power rail via is a minimum spacing allowable,
• determining the spacing between the location of the second power rail via and the locations of structures in the active region which may electrically interfere with the second power rail via, and
• changing the location of the second power rail via in response to the spacing between the location of the second power rail via and the location of one of the structures in the active region being less than a predetermined distance;
• and
• disposing the power rail and the power rail vias at the determined locations on the substrate.