| 摘要 |
PURPOSE:To prevent the reflection of unnecessary light by mounting on the surface of a wall to be irradiated a foam so that a very fine foreign substance such as kneaded compounds does not appear to reduce light intensity with the bubble of the foam and the like. CONSTITUTION:Light is directly or indirectly incident upon a foam 3 mounted on the surface of the wall of a pellicle frame 2 to irradiate. The radiated light enters into the bubble of the foam 3 to make irregular reflection, and the irregularly reflected light is finally brought into the absorbed state to reach such a state as not to exert a bad influence upon externals. That is, the foam 3 absorbs light and does not reflect light by itself. Then, a pellicle 4 is applied on the reticle pattern surface of a reticle 1 for the prevention of sticking very fine foreign substances and however when a laser beam enters into the inner wall surface of the pellicle frame 2, it is irregularly reflected in the case of the foam 3 being not provided there. Therefore, the foam 3 is stuck by a bonding agent in a particular position to absorb light, thereby eliminating erronous detection. |
