METHOD FOR CLEANING PHOTOMASK

摘要

PURPOSE:To make it possible to remove even extraneous matter unremovable only by irradiation with laser light as well as to selectively remove extraneous matter by irradiating the extraneous matter sticking on a photomask with laser light in an oxidizing atmosphere. CONSTITUTION:Residue of a photoresist as extraneous matter 3 sticks on a photomask 8 composed of a glass substrate 1 and Cr 2. Laser light 4 emitted from laser is condensed with a lens 5 and the matter 3 is irradiated with the condensed light 4. At this time, the atmosphere around the matter 3 is enclosed with a box 6 and gaseous oxygen is blown into the box 6 to maintain an oxygen atmosphere 7. The extraneous matter is selectively removed and even extraneous matter (stain) unremovable only by irradiation with laser light can be removed.