| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method to obtain a phase error of phase shift mask with good accuracy and to provide a method to produce a phase shift mask with improved phase accuracy. SOLUTION: This measuring device of phase difference is composed of an optical detecting means to irradiate a phase shift mask 5 with detecting light to catch enlarged images of the mask pattern in various defocused positions, a simulator part 13 to assume various phase differences and to numerically predict the abovementioned enlarged images, and a comparing and judging part 12 to determine the phase difference of the mask by comparing the detected optical images and the results of numerical calculation. A table showing the dependence of image dimensions on focuses corresponding to various defocused positions is prepared, and this table is compared with the image dimensions by the aforementioned signal process to measure the phase of the mask. Further, the measurement result is used as a feedback in the production process of the mask to decrease a phase error in the mask.</p> |
