| 摘要 |
PURPOSE:To remove the error component of a moire signal, and to make it possible to conduct a highly precise matching operation by a method wherein a first sensor which detects two moire signals separately, a second sensor which detects the two light quantities of coherent light separately, and an arithmetic operational processing circuit which is operated to extract a moire displacement signal based on the output of both sensors. CONSTITUTION:A first alignment mark 6, consisting of first and second diffraction gratings K1 and K2, is formed on a first substrate 1, a second alignment mark 7 consisting of a diffraction lattice K3 is formed on a second substrate 4, two moire signals having different phases are detected by superposing the image of refracted light of the second alignment mark 7, and the alignment operation of both substrates 1 and 4 is conducted based on the moire displacement signal in accordance with the difference of both moire signals. On the above-mentioned device, a first sensor 11 which detects both moire signals separately, a second sensor 14 with which each light quantity of the coherent light corresponding to the irradiation to the refraction lattices K1 and K2 regions generating moire signals having different phases, and an arithmetic processing circuit 15 which is arithmetically operated in order to abstract a moire displacement signal based on the output of both sensors 11 and 14 are provided. |
