US Patent 7767471 Auto routing for optimal uniformity control

A method for improving within-wafer uniformity is provided. The method includes forming an electrical component by a first process step and a second process step, wherein the electrical component has a target electrical parameter. The method includes providing a first plurality of production tools for performing the first process step; providing a second plurality of production tools for performing the second process step; providing a wafer; performing the first process step on the wafer using one of the first plurality of production tools; and selecting a first route including a first production tool from the second plurality of production tools. A within-wafer uniformity of the target electrical parameter on the wafer manufactured by the first route is greater than a second route including a second production tool in the second plurality of production tools.