Patent ID: 7728956

Claim:
A device manufacturing method, comprising: modulating a beam of radiation using an array of individually controllable elements, wherein a control system is used to provide control signals to the array of individually controllable elements; storing pattern data in a first buffer, wherein the pattern data corresponds to a first device to be exposed on the substrate; providing the control signals to the array of individually controllable elements, such that the beam of radiation is modulated by the pattern data; projecting the modulated beam of radiation onto a substrate to expose the first device on the substrate; storing in a second data buffer pattern variation data corresponding to at least one change to a part of the pattern data stored in the first data buffer; modifying the pattern data of the first data buffer using the pattern variation data of the second data buffer to generate modified pattern data, which corresponds to a second pattern of a second device to be exposed on the substrate; providing the control signals to the array of individually controllable elements, such that the beam of radiation is modulated by; projecting the modulated beam of radiation onto the substrate to expose the second device on the substrate; and testing the first and the second devices to determine an optimal pattern for a device.