| 摘要 |
A method and apparatus precisely adjust the image focusing characteristics of a projecting optical system of a scanning exposure apparatus. When the image focusing characteristics of the projecting optical system are measured, e.g., a fly eye lens for use in a normal scanning exposure process is switched to a fly eye lens composed of square-shaped lens elements thereby changing the slit-shaped illumination area of a reticle to a square-shaped illumination area. The positions and contrast of projected images of test marks in the square-shaped area are measured, thereby measuring the image focusing characteristics of the projecting optical system. According to the result of the measurement, e.g., an image focusing correction mechanism corrects the image focusing characteristics. After completion of adjusting the image focusing characteristics, the illumination area is returned to the normal illumination area and the image focusing characteristics are evaluated for confirmation. A further correction is made if the evaluation result indicates that further correction is required.
|
