Abstract: A method of forming a substantially defect-free mask for optical and phase-shift lithography. The method involves depositing a transfer layer on a mask layer deposited on a transmissive substrate, forming in the transfer layer a mask image to be defined in the mask layer, inspecting the image formed in the transfer layer, repairing the image formed in the transfer image, and transferring the corrected image from the transfer layer into the mask layer. The repair of the transfer layer is accomplished by removing unwanted portions of the transfer layer followed by filling any unwanted voids therein with a selected material. Preferably, the fill material has the same desirable etching and/or optical characteristics as the surrounding transfer layer. However, any material that is substantially opaque to the radiation used to transfer the image from the transfer layer to the mask layer can be successfully employed.