| 摘要 |
PURPOSE:To accurately, quickly and automatically inspect photomasks without individual difference by scanning measuring light simultaneously on a reference mask and a sample with matched degree of parallelism by moving and adjusting the mounting positon, and detecting edge signals and scanning distances, calculating and comparing the values. CONSTITUTION:Holders 2 and 3 with adjustable rotation angles of X and Y directions are put on a table 1 which is movable to X and Y directions. A sample mask 15 and a reference mask 16 are put on the holders 2 and 3 respectively, and starting positons of measurement and degrees of parallelism of these masks are matched each other. Then the light of a laser 4 is divided for both masks, applied and made to scan a pattern by moving the table 1 or the applying light. Reflecting light from the pattern edge is detected as pulse signals by photoelectric elements 9', 9'' for example arranged at the sides of the applying light pass. Measurement of patterns and distances between patterns can be obtained from intervals of the pulses. These detected signals are inputted to calculating devices 11 and 12. Evaluation of accuracy and judgement of propriety are done automatically by comparing these calculated values. In this way, measurement becomes accurate, and measuring time becomes short. |
