Method of and apparatus for washing photomask and washing solution for photomask
View Patent ↗Organic matter and metal impurities present on the surface of a photomask are removed. Foreign matter still adhering to the surface of the photomask is removed with H 2 gas dissolved water. The photomask is dried. Thus provided is a method of washing a photomask in a manner which permits attaining an effect of removing foreign matter equivalent or superior to that of a conventional method with a small amount of chemical solution and reducing the amounts of chemicals and high purity water.
1. A method of washing a photomask comprising: forming a a phase-shift photomask with MoSiON film
removing organic matter and metal impurities present on the surface of the photomask;
removing foreign matter adhering to said surface of said photomask with H 2 gas dissolved water; and
drying said photomask,
wherein said photomask is a halftone mask, said H 2 gas dissolved water contains ammonia and the concentration of said ammonia is not more than 1%.
2. The method of washing a photomask in accordance with claim 1 , wherein said H 2 gas dissolved water is alkalized.
3. The method of washing a photomask in accordance with claim 2 , wherein said H 2 gas dissolved water is alkalized with ammonia.
4. The method of washing a photomask in accordance with claim 1 , also employing ultrasonics waves in said step of removing foreign matter.
5. The method of washing a photomask in accordance with claim 4 , wherein said step or removing organic matter and metal impurities employs ultrasonics waves.
6. The method of washing a photomask in accordance with claim 4 , wherein said foreign matter is particulate foreign matter.