Magnetically Opposed, Iron Core Linear Motor Based Motion Stages For Semiconductor Wafer Positioning

Methods and systems for realizing a high throughput wafer positioning system with high positioning accuracy are presented herein. The high throughput, high accuracy wafer positioning system is employed to measure structural and material characteristics (e.g., material composition, dimensional characteristics of structures and films, etc.) associated with different semiconductor fabrication processes. In one aspect, iron core linear motor assemblies are arranged in a magnetically opposed configuration such that the magnetic attraction forces inherent to each opposing iron core linear motor assembly largely cancel one another. The reduced force applied to sensitive stage frame elements, in turn, reduces induced deformations and stage positioning errors. In some embodiments, a wafer positioning system includes stacked magnetically opposed long stroke stages. In some of these embodiments, both magnetically opposed long stroke stages employ magnet tracks mechanically coupled to the intermediate frame of the stacked stage assembly.