column together with a first wafer chucking means and a second wafer chucking means the primary imaging column functions to image a mask pattern on the wafer while the second imaging column irradiates an energy beam on a defect on the wafer to repair the mask pattern the invention provides a solution for the mask repair problem in difficult cases of mask repair instead of repairing the defect at the mask the defect is repaired at the resist image as long as the mask is capable of being imaged to the photoresist the defect is reproduced in the resist either in the form of additional unwanted resist or missing resist before the resist is developed the defect exhibits itself as an exposed or unexposed latent image the unexposed resist latent image can be repaired by further exposure to radiation to create an exposed image at the missing part on the other hand the exposed resist latent image can sometimes be repaired by further exposure to radiation to cross link the exposed photoresist material to render it non developable in order to correct the defect the present invention provides a novel apparatus for replicating a mask image and for repairing the subsequent resist latent image after a mask pattern is written and etched on the substrate an inspection identifies the type size and location of the.