METHOD OF COLLECTING PHOTOMASK

摘要

A laser beam with a pulse width of 3-16 ps is used to correct a photomask consisting of chromium film (2) and chromium oxide film (3) formed on a substrate (1). Preferably the laser beam has a wavelength of 600-1100 nm. The laser beam of 3-16 ps pulse width selectively cuts the chromium film (2) and the chromium oxide film (3) without damage to the substrate (1), and the photomask is corrected with accuracy better than 1 mu m. As a result, the mask can have sharp edges without opaque defects.