| 摘要 |
PURPOSE:To correct automatically a reducing magnification error, by measuring a mark on a substrate through a reduce-projecting lens and a reticle, operating the reducing magnification error, and moving slightly the reduce-projecting lens in the optical axis direction. CONSTITUTION:A pattern on a reticle 22 being an original picture is illuminated by condensing the illuminating light from a light source by a condensing lens 21, and is reduce-projected onto a substrate 24 through a reducing lens 23. The shaded portion in the figure shows a reference member of an immovable state. The substrate 24 is installed on a moving base constituted of a Z moving base 30 being movable in the optical axis direction and an XY moving base 31 being movable on the plane falling at a right angle with the optical axis, and is provided with an automatic focusing mechanism so that the substrate 24 face is always held at a focal position where an image is formed by the reducing lens 23. A relative position of the substrate 24 can be derived by an operating circuit 35 by measuring a position of the moving base by a laser measuring meter 39. |
