Abstract: Differently-sized features of an integrated circuit are formed by etching a substrate using a mask which is formed by combining two separately formed patterns. Pitch multiplication is used to form the relatively small features of the first pattern and conventional photolithography used to form the relatively large features of the second pattern. Pitch multiplication is accomplished by patterning a photoresist and then etching that pattern into an amorphous carbon layer. Sidewall spacers are then formed on the sidewalls of the amorphous carbon. The amorphous carbon is removed, leaving behind the sidewall spacers, which define the first mask pattern. A bottom anti-reflective coating (BARC) is then deposited around the spacers to form a planar surface and a photoresist layer is formed over the BARC. The photoresist is next patterned by conventional photolithography to form the second pattern, which is then is transferred to the BARC.