| 摘要 |
PURPOSE: To realize more accurate alignment by detecting a light region transmitted through a substrate as an accurate slit edge of a light projected through an aligning slit in a reticle. CONSTITUTION: A reticle slit 3 disposed above a reticle 2 is projected onto the upper surface 6 of a transparent substrate 11 and the image 4 of the slit is focused. When the image 4 of the reticle slit is located closely to a plate slit 15, a part of the light passes through the plate slit 15 and arrives at a sensor 17 in a stage. When the substrate 11 is shifted through relative movement of a stage 14 to the slit image 4, a larger or smaller quantity of light arrives at the sensor 17 from the image. More specifically, accurate alignment can be attained in both X and Y directions using the sensor 17 comprising two pairs of reticle slit 3 intersecting perpendicularly with each other, two pairs of plate slit 15 and four cells. |
