Abstract: A method for manufacturing an integrated circuit includes: performing ion implantation on a wafer to make a chip in the wafer have an original doping concentration; dividing the chip into a plurality of regions; and controlling at least one region of plurality of the regions to not have further ion implantation performed thereon, thereby making the region only have single ion implantation performed thereon utilize the original doping concentration as a doping concentration of N-wells or P-wells of transistors in the region. Additionally, the region corresponds to signal output circuits of the integrated circuit.