ANGLED-WEDGE CHROME-FACE WALL FOR INTENSITY BALANCE OF ALTERNATING PHASE SHIFT MASK

摘要

A method and structure for a phase shift mask having a light reducing layer with sloped sidewalls. In some embodiments, the sloped sidewalls can help improve the image imbalance. The mask comprising: a substrate having a first region, a second region and a third region; the third region position between the first region and the second regions; an light reducing layer over the substrate having a first opening over the first region and a second opening over the second region; the first opening and the second opening defined by light reducing layer sidewalls; the sidewalls of the opaque layer are slanted at an angle less than 90 degrees with the plane of the top surface of the substrate.