6. Conclusions

The aim of this comparison was to assess the situation in France with regard to the calibration and accuracy of AFM and SEM measurements. To this end, six arrays were circulated among the 26 participants. Three gratings were VLSI standards with a nominal pitch of 1.8 µm and a step height of 40 nm, while the other three were gratings whose pitch and step height were unknown and yet to be determined (nominal grating pitch 900 nm, step height 60 nm). The aim was for each participant to measure the dimensional properties of these two gratings before and after calibration of their instrument.

The comparison showed that the vast majority of instruments were not calibrated and that users were, for the most part, unfamiliar with calibration procedures. By following the protocol provided, participants reduced overall measurement discrepancies by a factor of 2 to 3 for network...