| 摘要 |
PURPOSE:To contrive to enhance the throughput of an X-ray exposure equipment by a method wherein the equipment is made in such a constitution that both of the real images of the masking patterns and the virtual images of the masking patterns, which are reflected on the mirror surface of the wafer, are focussed by the optical detecting system to be arranged in the oblique upper direction to the masking patterns and the gap between the masking patterns and the wafer can be set at the prescribed value in a state that both thereof are in focus. CONSTITUTION:The design of masking patterns 7a and 7b is kept made in such a way that the mirror part of a wafer 2 is arranged under the masking patterns 7a and 7b. The virtual images 7a' and 7b' of the masking patterns 7a and 7b are formed by the mirror surface of the wafer 2. There when a detecting part 6 is disposed to the wafer in the direction at an angle of theta from the wafer, the plane that links the masking pattern 7a with the virtual image 7b' becomes a focal surface 16 and an imaging surface 17 is formed on the plane parallel to the focal surface 16. In this case, when the focal point is focussed on a plane where the length between the imaging surface 17 and the focal surface 16 becomes a length (l0), the focal point is not focussed on the pattern 7a and the virtual image 7a', which are located at places where the two lengths between the imaging surface 17 and the focal surface 16 respectively become lengths (l1) and (l2). Consequently when the wafer 2 is made to vertically move in such a way that the two points are focalized, the gap between the masking patterns and the wafer can be set correctly and swiftly at an accuracy that is decided by the resolving power of the optical system and the feedback accuracy of a vertically moving mechanism 4. |
