Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 01 processing: Difference between revisions

<br/>Unfortunately, the centering does not compensate for major or minor flats. The center position will therefore typically be displaced several hundred µm from the center of the substrate along the Y-axis due to the major flat, and possibly also shifted due to any minor flats. These shifts have successfully been compensated during file conversion, which yielded a centering accuracy of ±200µm. The table below lists the correction needed during file conversion in order to compensate for major and minor flat, dependent on the position of the minor flat. Keep in mind that the tolerances of substrate diameter and flat lengths in the SEMI wafer standard introduce uncertainties to these numbers in the order of 0.5-1mm. Accurate positioning of the design relative to the substrate center would require measurement of diameter and flat lengths of the individual substrate, and subsequent recalculation of the correction values.