| 摘要 |
PURPOSE:To enable highly accurate positioning of objects by a simple structure even in the case where the wavelength of exposure light and that of alignment light are different by interposing a projection lens between objects arrange so as to face each other, forming a first and a second marks on each of the objects, and arranging two diffraction points spaced at a specified interval on each of the marks. CONSTITUTION:Two mask marks 41-1, 41-2 composed of diffraction grating are formed as a mask 11 on a first object, and the marks 41-1, 41-2 are spaced at a specified interval 2r. A second mark as a wafer mark 42 composed of a diffraction grating is formed on a wafer 12 as a second object. From a point (a) of the mask 11, exposure light is focused on a wafer 12 via a projection lens 13; alignment light from a laser 43 is divided into two beams by mirrors 44-1, 44-2 as transferring means, transferred by the mark 41-1, 42-2, subjected to transmission diffraction by each of the mask marks, and two diffraction lights are realized, thereby enabling highly accurate positioning of objects. |
