| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a photomask enabling high precision focus measurement by decreasing load on mask manufacturing. <P>SOLUTION: The photomask PM1 includes a shading part shielding light, and first and second transmission parts transmitting light. The photomask comprises an asymmetric diffraction grating pattern 2 substantially satisfying that θ and n are 163°≤360°/(n+2)≤197°, and a reference pattern 3 for obtaining images that is a reference when measuring shift of the image of the asymmetric diffraction grating, when an absolute value of a difference between a light phase of the first transmission part and the light phase of the second transmission part is θ(≠90°) and the ratio of width of the shading part, the width of the first transmission part and the width of the second transmission part is n:1:1 (n: positive real number, other than 2). <P>COPYRIGHT: (C)2006,JPO&NCIPI |
