A
photolithography and etch process sequence includes a
photomask having a pattern with compensation features that alleviate patterning variations due to the proximity effect and
depth of focus concerns during
photolithography. The compensation features may be disposed near isolated or outermost lines of a device pattern. A
photoresist pattern is formed to include the compensation features and the pattern etched to form a corresponding etched pattern including the compensation features. After
etching, a protection material is formed over the layer and a trim
mask is used to form a further
photoresist pattern over the protection material. A subsequent
etching pattern etches the protection material and removes the compensation features and results in the device lines being formed unaffected by proximity effects.
Flare dummies may additionally be added to the
mask pattern to increase pattern density and assist in endpoint detection.
Flare dummies, like the compensation features, are subsequently removed by a
photolithography and
etching process sequence.