A technique for electrically measuring alignment errors is described and employed to characterize a GCA 4800 DSW stepper. The experimental accuracy was determined to be +I~ 0.05 microns for all line-width measurements. The GCA 4800 stepper’s day - to - day performance was determined to fluctuate between 0 and -1 micron in X and between 0 and +2 microns in Y. Average alignment ranges of +/- 0.74 and +/-0.95 microns in X and Y were ob served across four samples during the wafer-to-wafer variation testing within one run. These errors were directly related to the accuracy of the “pass-shift” values used by the stepper’s control software.
Kosa, Jeffrey D.
"Alignment Error Characterization Using Electrical Probing Techniques,"
Journal of the Microelectronic Engineering Conference: Vol. 5
, Article 12.
Available at: http://scholarworks.rit.edu/ritamec/vol5/iss1/12