| 摘要 |
PURPOSE:To obtain a photomask whose substrate is free from invisible scratches and has small roughness on one principal surface on which the light shielding film is not present by using a specified soln. when a light shielding film on a substrate is selectively etched. CONSTITUTION:One principal surface of a transparent substrate of quartz glass or the like is coated with a light shielding film to form a photomask substrate. A resist is applied to the light shielding film, exposed and developed to form a resist pattern on the film and this film is selectively etched with a mixed aqueous soln. contg. one or more among ammonium hydrogenfluoride, ammonium fluoride, hydrosilicofluoric acid and fluoboric acid and hydrogen peroxide and/or nitric acid. The resist pattern is then stripped off to obtain a desired photomask. |
