| 摘要 |
PURPOSE:To enable stable and highly accurate alignment of an optical axis of exposure light to be made by reading interference light due to alignment irradiation light in a slant direction through the similar marks of a reticle or a mask and a wafer which are at conjugate positions optically. CONSTITUTION:Two thin light sources La for alignment with different wavelength and phase from light in a slant direction for a light axis AX of exposure light Le through a window Rs of a light-screening body Sh of a reticle R which is at conjugate position optically in reference to a wafer W forms image at a wafer mark WM at the outside near the exposure region of the wafer W. Then, a mark WM is read by interference light from the mark WM. Then, reading a mask mark at a position corresponding to a window Rs of mask while shifting a stage two-dimensionally makes it possible to align a substrate which can be exposed stably and highly accurately with improved resolution reading. |
