The AVI Photomask Metrology System

Accuracy & Repeatability

Linewidth Accuracy  Repeatability  Defect Accuracy   Print in Landscape mode for all graphs and text to appear.

Linewidth Accuracy view full size graph view full size graph Data courtesy of TSMC Measurements of a CD test pattern, isolated lines. KMS and AVI data taken with a KMS-400 with white light. The AVI computer digitized images from the KMS display. KMS measurements were calibrated with the existing calibration on the KMS. AVI measurements are total flux divided by intensity range and pixel size. Pixel size is determined from pitch measurement. Conclusions:     AVI measurements are linear down to the smallest lines that will print.     AVI flux-area measurements can accurately measure subwavelength lines with a linear, single point calibration.     "Transmission linewidth" measurements based on flux-area size define a linewidth which can be duplicated on any optical system. Accuracy is limited by the printed line pitch and repeatability is limited by the illumination level control. [back to top]

Defect Accuracy view full size graph AVI measurements are within 40 nm of SEM measurements for defects from 0.05 µ to 0.5 µ (after 100 nm diffraction offset). [back to top]

Repeatability AVI repeatability is better than 3 nm, or 1% of the defect size. [back to top]

The AVI Photomask Metrology System     How does it work?   What can I measure? Why do I need it? Accuracy and repeatability? Can I save money?   System Specs