Method and mask for enhancing the resolution of patterning 2-row holes

Abstract

A photolithography mask including a plurality of mask features. Adjacent mask features are separated by a gap and are offset from each other such that individual mask features have one-side dense portions and two-side dense portions. Also a photolithography method that includes a step of providing a substantially opaque mask having N stepped rows of offset, substantially transparent, rectangular mask features, where N is an integer and N≧2. The method also includes illuminating a photoresist layer located over an underlying material with dipole illumination through the substantially transparent, rectangular mask features in the substantially opaque mask to form 2N rows of exposed regions in the photoresist layer. The exposed regions have a substantially elliptical or substantially circular shape when viewed from above the photoresist layer.

Dependencies are inferred from the claim text.