Patent ID: 6680151
Filing Date: 2004-01-20
Classification: G03F

Abstract:
An alternating phase mask for an exposure of a photosensitive layer in a photolithography process, the alternating phase mask comprising:at least one T pattern structure having at least one first opaque segment with a longitudinal side and at least one second opaque segment, said second opaque segment joining said longitudinal side of said first opaque segment at a joining point and subdividing said first opaque segment into two opaque partial segments on both sides of said joining point; and transparent area segments, including first transparent area segments and second transparent area segments, disposed in an alternating sequence on both sides of said two opaque partial segments of said first opaque segment and of said second opaque segment, said transparent area segments imparting a mutual phase shift by 180Â° on exposure radiation passing through said transparent area segments; said T pattern structure having corners and at one of said corners where said second opaque segment meets said first opaque segment, one of said first transparent area segments and one of said second transparent area segments disposed such that the exposure radiation passing through them experiences a phase jump by 180Â° there, a point producing the phase jump forming an angle with each of two affected sections of said first and second opaque area segments, and said angle substantially bisecting a corner angle of said T pattern structure; said two affected sections of said first and second transparent area segments being spaced apart from one another by a slot formed therebetween being significantly smaller than a width of each of said two affected sections of said first and second transparent area segments, and said slot separating said two affected sections of said first and second transparent area segments and forming said angle with respect to said corner of said T pattern structure.