Patent ID: 8735181

Claim:
A method for manufacturing a semiconductor device, comprising: forming a plurality of gate electrodes with different widths and different lengths on a wafer; measuring one of a gate width and a gate length of the plurality of gate electrodes formed on the wafer to obtain a distribution of one of the gate width and the gate length having one of a small gate width and a small gate length and having one of a large gate width and a large gate length; calculating data of an ion implantation dosage for making uniform a threshold voltage in a wafer surface on the basis of distribution of one of the measured gate width and the measured gate length in a wafer surface, wherein the data of the ion implantation dosage corresponding to a region of a distribution with the small gate width or the small gate length is larger than a region of a distribution with the large gate width or the large gate length; and implanting ions into the wafer on the basis of the calculated data of the ion implantation dosage, wherein the ion implantation dosage is controlled by changing a scanning speed in accordance with a position of the wafer during a scanning along a scanning line, and wherein the scanning speed corresponding to a region of a distribution with the small gate width or the small gate length is slower than a region of a distribution with the large gate width or the large gate length.