Summary: ALIGNMENT ERRORS IN XY STAGE METROLOGY
Shorya Awtar, Alexander H. Slocum
Precision Engineering Research Group, Massachusetts Institute of Technology
77 Massachusetts Avenue, 3-445, Cambridge MA 02139
This paper discusses a fundamental question in the characterization of XY stages: Is the orthogonality
error of the stage distinguishable from a target block alignment error without explicitly measuring the
target block misalignment? The conclusion reached here is that, in general, this is not possible using any
metrology setup or any number of measurements.
Keywords: XY Stage Characterization, Metrology Alignment Errors
In the error mapping of an XY stage, one of the primary objectives is to measure the cross-axis and yaw
motion errors of the stage . Several deviations from ideal behavior can occur in this characterization.
Some of these are attributed to the stage itself while others arise from the metrology setup. It is important
to design a metrology setup and scheme that explicitly determine the former discard the latter.