| 摘要 |
PURPOSE:To improve accuracy of alignment, by providing a reflector for transmitting a main exposure wavelength light and reflecting alignment light above a reticle. CONSTITUTION:The alignment illumination light emitted from a He-Ne laser source passes through M5, L13, and M4 and a reticle R, and is reflected by a dichroic mirror M2 installed at the position located by dl/2 above the reticle R, is passed through a projection objective lens L10, and illuminates a wafer W. There is a key mark Wa formed at the first exposure on the wafer W, and the light is reflected by W, is passed through L10, is reflected by M3, and an image is formed on the pattern face Rp of R. An alignment mark Ra is provided on Rp, the light passes through M4, L13, L14 and forms double images of Wa and Ra at the image position. W and R are relatively moved for positioning, and the exposure main wavelength light 10 is cast from above M3. |
