The present disclosure provides one embodiment of an integrated circuit (IC) method. The method includes receiving an IC design layout having a plurality of IC regions each including an IC pattern; performing a dissection process to the IC design layout; and performing a correction process to the IC design layout using a correction model that includes proximity effect and location effect. The correction process includes performing a first correction step to a first IC region of the IC regions, resulting in a first corrected IC pattern in the first IC region; and performing a second correction step to a second IC region of the IC regions, starting with the first corrected IC pattern, resulting in a second corrected IC pattern.