A new optical measurement method for verifying the exact change of thin films on the QZ blanks with ellipsometer

摘要

The information of the chromium top layer is important in photomask fabrication. Resist coating process and optical transmittance change of chromium after mask cleaning process depend on the surface morphology and thickness. In this paper, we present that ellipsometry, the nondestructive optical measurement method, is an effective and convenient method for the inspection of chromium oxide on the quartz blank. We checked data obtained by ellipsometry for chromium surface morphology with atomic force microscope, for surface energy with contact angle measurement, and for optical density change with optical transmittance measurement. It turns out that ellipsometry gives successfully the information of chromium oxide on the quartz blank.