| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a phase shift mask used for an optical lithographic system, accurately positioning features formed on a workpiece, and having little light leak. SOLUTION: Phase shift features 11 and positioning marks 13 are provided in sets, and the respective marks 13 have the same thickness and material. The material is a chromium nitride/oxide, for example, and it has slight permeability for the light used in an optical lithographic system. Each set is located on a slab of a crystal 10. Positioning shutter layers 12 are located between the positioning marks 13 and the phase shift features 11 to suppress the leak of the light from the phase shift features 11 to positioning areas. The partial surfaces of the positioning shutter layers 12 and the whole faces of the reinforcing positioning marks are reinforced by opaque layers 32, 33 made of chromium respectively, for example. Reinforced chip shutter layers 14, 34 may be longitudinally provided at the end sections of the reinforced positioning marks to suppress the light leak between chip areas in the other step and repeat processes.</p> |
