| 摘要 |
PURPOSE:To obtain higher resolution with a thin resist layer by mounting a special stop which has higher transmissivity at the center part than at the peripheral part instead of a uniform stop which determines the size of a secondary light source. CONSTITUTION:When resist is thin, light from the center part of the secondary light source is not used so as to improve the resolution and only light from the peripheral part of the secondary light source is used for exposure. Consequently, the special stop is, for example, a stop having a annular passing area. In another way, a stop having a distribution of transmissivity is used instead thereof. Its transmissivity is so distributed that the transmissivity is higher toward the periphery and lowest or zero at the center. This special stop is only mounted instead of the aperture stop of the exit of an optical integrator. When a thin resist layer is used, the resolution is higher and higher as a pattern in use is thinner and thinner toward the outside of the secondary light source. For the purpose, only the light from the peripheral part of the secondary light source is used to obtain higher resolution. |
