| 摘要 |
PURPOSE:To accurately and easily align the reticle of an LSI with a wafer with a simple structure in the atmosphere by employing a second harmonic wave of an Ar laser as an aligning light source when an excimer laser is used for an exposure illumination. CONSTITUTION:A reticle 14 is disposed between an Ar laser 11 of a second harmonic wave and a first Fourier conversion lens 15, an image output as a secondary light source from the pattern of a first lattice 10 of the reticle 14 is temporarily condensed by the lens 15, the image of the pattern of the reticle 14 is further projected through a second Fourier conversion lens 17 to a wafer (semiconductor substrate) 18 via a contraction projecting optical system 19. That is, a space filter is disposed for use in an alignment optical system, and the image of a circuit pattern on the reticle is contraction-projected, after the alignment is completed, on the wafer. Thus, the pattern on the reticle is accurately aligned through interference fringes as a medium on the wafer by a through lens system, and the pattern on the reticle is exposed and formed on the wafer. |
