| 摘要 |
PURPOSE:To reduce the reflection of light between an exposure optical system and a reticle and to suppress an irregularity in the illuminance of an exposure area by using the reticle where a reflection preventive film is formed. CONSTITUTION:The reticle 1 is interposed between the condenser lens 3 and reduction projection lens 4 which form the exposure optical system and light 6 is transmitted to expose resist on a semiconductor wafer 5. At this time, the reticle 1 which has the reflection preventive film 2 formed on the surface is used and reflected light which travels to the reticle 1 is transmitted like light 7. Then the film 2 is formed such a material that n1<n2<n3, where n1 is the refractive index of air, n2 is the refractive index of the material of the film 2, and the n3 is the refractive index of the reticle 1. Further, the film thickness (d) of the film 2 is set preferably satisfying n2Xd aXlambda/4 (where (a) is an odd number and lambda is the wavelength of light used for the exposure). |
