Abstract: A method for suppressing the optical proximity effect bias within a wafer by compensating the optical proximity effect within the wafer includes the steps of: Firstly, performing a first exposure step with a first exposure parameter setup to transfer a pattern from a photomask to a first die of the wafer. Secondly, performing a second exposure step with a second exposure parameter setup to transfer the pattern from the photomask to a second die of the wafer, wherein the first and second exposure parameter setups are adjusted according to the local optical proximity effect bias of the dies within the wafer. The exposure parameter setup can be numerical aperture setup, partial coherence setup, exposure energy setup, exposure time setup, exposure light intensity setup, or best focus setup. The light source used in the exposure steps can be an I-line, G-line, KrF laser, ArF laser, X-ray, or e-beam.