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

摘要

A method for forming a semiconductor device is presented. The method includes providing a substrate having a photoresist thereon and transmitting a light source through a mask having a pattern onto the photoresist. The mask comprises a mask substrate having first, second and third regions, the third region is disposed between the first and second regions. The mask also includes a light reducing layer over the mask substrate having a first opening over the first region and a second opening over the second region. The first and second openings have layer sidewalls. The sidewalls of the light reducing layer are slanted at an angle less than 90 degrees with the plane of a top surface of the mask substrate. The method also includes developing the photoresist to transfer the pattern of the mask to the photoresist.