System and method for calibrating mirrors of a stage assembly

Abstract

A stage assembly () for moving and positioning a device () is provided herein. The stage assembly () includes a stage base (), a device table (), a stage mover assembly (), a measurement system (), and a control system (). The stage mover assembly () moves the device table () along an X axis, along a Y axis, and about a Z axis relative to the stage base (). The measurement system () includes a first X mirror (A) for monitoring the position of the device table () in an alignment position (A) and a second X mirror (B) for monitoring the position of the device table () in an operational position (B). In one embodiment, the stage assembly () includes a first fiducial mark () and a second fiducial mark () that are secured to the device table () to determine the relative position of the X mirrors (A)(B). Alternately, in another embodiment, the stage assembly additionally includes a third fiducial mark () secured to the device table () for determining the relative positions of the X mirrors (A)(B). In both embodiments, the control system () utilizes the measured position of the fiducial marks relative to the first X mirror (A) and the second X mirror (B) to determine the position of the first X mirror (A) relative to the second X mirror (B). These features allow for more accurate positioning of the device () by the stage assembly () and better performance of the stage assembly ().