| 摘要 |
<p>PURPOSE:To reduce the damage to master mask and to eliminate the error which takes a reference mask for other one by comparing the scale pattern of the reference mask and the pitch pattern of photomask and by measuring the deviation. CONSTITUTION:A chip pattern 4 which forms horizontal and vertical pitch purpose patterns 5, 6 of the same shaped pattern is formed in line on the surface of a photomask 2 to be measured. The same shaped pattern 7 as the patterns 5, 6 is lined up in the horizontal direction at about central line at regular intervals. And a scale pattern is formed. The following is inspection procedurse: Firstly, a pattern 7 is fixed to form a line in accordance with the transverse direction of a table 1. A pattern 5 is fixed in the same way. Secondly, a mask 2 is adjusted so that microscope images 5a' and 7a' may fall on. Thirdly, the table 1 moves by the number of (transverse pitch of a pattern 4)X(transverse pattern 4). Fourthly, the images 7b' and 5b' are superposed each other and the quantity of slight displacement is read. The same measurement is made by changing the direction of the mask 2 by 90 deg. for the table 1.</p> |
