11. The method of claim 10 , wherein the forming the IC features in a material layer includes: patterning a first photoresist layer on the material layer using the first photomask; etching the material layer through openings of the first photoresist layer; removing the first photoresist layer; patterning a second photoresist layer on the material layer using the second and third photomasks; etching the material layer through openings of the second photoresist layer; and removing the second photoresist layer.
12. The method of claim 11 , wherein the patterning the second photoresist layer includes: coating the second photoresist layer on the material layer; exposing the second photoresist layer using the second photomask; exposing the second photoresist layer using the third photomask; and thereafter, developing the second photoresist layer.