FOCUSING PERFORMANCE MEASURING DEVICE FOR FOCUSING OPTICAL SYSTEM

摘要

PURPOSE:To accurately measure a distortion aberration projecting magnification, performance of focusing optical system, such as a curved surface of an image by employing an original picture on which a plurality of marks are arranged, providing a mask on which a reference mark is disposed at a position to be focused at the mark by a projecting optical system, and measuring the relative position of the image of the mask and the focused mark. CONSTITUTION:A mask 5 on which a reference mark 4 is arranged is disposed at the focusing position of a projecting optical system 3. The array of the marks 4 correspond by one by one to the marks 2 on an original picture (reticle) 1 to be projected. An XYZ stage 8 is moved through an XYZ stage control system 17 by a control system 16, and the relative position data of the mark 4 is obtained for the mark 2 of a predetermined position by a mark detector 7. Then, it is compared with the position data of the mark measured in advance accurately, and the displacement from an ideal position of a projected mark is calculated. Thus, the performance of a focusing optical system, such as a distortion aberration or the like including the magnification error of the projected image can be accurately measured.