| 摘要 |
PURPOSE:To reduce the concentration of light on the central part of a surface on which the light is projected as well as to reduce the reflection of the light and to increase transmissivity by forming an antireflection film fit for the wavelength of light from the light source of an exposer on the surface of the transparent substrate of mask forming an original pattern. CONSTITUTION:The substrate 1 of a mask is made of quartz or low expansion glass, a Cr pattern 2 and a chromium oxide film 3 are successively formed on the substrate 1 and the entire substrate 1 is coated with an antireflection film 4 by vapor deposition with electron beams. In the case of an exposer with a light source emitting light having wavelength of G line (wavelength lambda=435 nm), a three-layered film consisting of a magnesium fluoride layer (109 nm=lambda/4), a zirconium oxide-tantalum pentoxide mixed layer (218 nm=lambda/2) and an aluminum oxide layer (109 nm=lambda/4) is formed as the antireflection film 4 on the quartz substrate 1. The distribution rate of illuminance is improved from + or -1.5% to + or -0.6% by forming the film 4 and >=99.5% transmissivity is attained. |
