Method to mitigate resist pattern critical dimension variation in a double-exposure process

A photolithography method comprising:

• forming a photoresist layer over a substrate;
• forming a first topcoat layer over the photoresist layer;
• exposing the first topcoat layer and the photoresist layer to a first radiation;
• developing the photoresist layer to remove the first topcoat layer and to form a first pattern in the photoresist layer;
• forming a second topcoat layer on the patterned photoresist layer;
• exposing the second topcoat layer and the patterned photoresist layer to a second radiation;
• removing the second topcoat layer with an organic solvent, wherein the organic solvent does not dissolve the photoresist layer;
• and
• developing the patterned photoresist layer to form a second pattern in the photoresist layer.