A system and method for controlling a dosage profile is disclosed. An embodiment comprises separating a wafer into components of a grid array and assigning each of the grid components a desired dosage profile based upon a test to compensate for topology differences between different regions of the wafer. The desired dosages are decomposed into directional dosage components and the directional dosage components are translated into scanning velocities of the ion beam for an ion implanter. The velocities may be fed into an ion implanter to control the wafer-to-beam velocities and, thereby, control the implantation.