A mask fabrication and repair technique including multiple exposures is provided. In this multiple exposure technique, the first exposure can define the critical dimensions (CDs) of the shapes for the mask. A subsequent exposure can eliminate isolated defects and significantly reduce the size of defects proximate to the desired shapes on the mask. Because similar processes (i.e. forming, exposing, and developing a photoresist layer) are used for creating and repairing the mask, certain repair-related defects, such as phase and transmission defects, can be minimized. Wafer repair can also be performed using the same multiple exposure technique.

A multilayer film is used as a buffer layer to minimize the size of defects on a reticle substrate prior to deposition of a reflective coating on the substrate. The multilayer buffer layer deposited intermediate the reticle substrate and the reflective coating produces a smoothing of small particles and other defects on the reticle substrate. The reduction in defect size is controlled by surface relaxation during the buffer layer growth process and by the degree of intermixing and volume contraction of the materials at the multilayer interfaces. The buffer layers are deposited at near-normal incidence via a low particulate ion beam sputtering process. The growth surface of the buffer layer may also be heated by a secondary ion source to increase the degree of intermixing and improve the mitigation of defects.

A buffer-layer to minimize the size of defects on a reticle substrate prior to deposition of a reflective coating on the substrate. The buffer-layer is formed by either a multilayer deposited on the substrate or by a plurality of sequentially deposited and annealed coatings deposited on the substrate. The plurality of sequentially deposited and annealed coating may comprise multilayer and single layer coatings. The multilayer deposited and annealed buffer layer coatings may be of the same or different material than the reflecting coating thereafter deposited on the buffer-layer.

A system and method for optimizing the production of lithography reticles involves identifying "proximity effect halos" around tight tolerance features in an IC layout data file. Features and defects outside the halos will not have a significant effect on the printing of the tight tolerance features. During reticle formation, the tight tolerance features and associated halos can be carefully written and inspected to ensure accuracy while the other portions of the reticle can be written/inspected less stringently for efficiency. The halo width can be determined empirically or can be estimated by process modeling. If an electron beam tool is used to write the reticle, a small spot size can be used to expose the tight tolerance features and the halos, whereas a large spot size can be used to expose the remainder of the reticle. A reticle production system can include a computer to read an IC layout data file, identify tight tolerance features, and define proximity effect halos. Tight tolerance features can be individually selected or automatically flagged according to user specifications. A graphical user interface can be provided to enable user input and control. The reticle production system can be coupled to a remote IC layout database through a LAN or a WAN. The reticle production system can be coupled to directly send a reticle data file to a reticle-writing tool.

A lithography reticle advantageously includes "proximity effect halos" around tight tolerance features. During reticle formation, the tight tolerance features and associated halos can be carefully written and inspected to ensure accuracy while the other portions of the reticle can be written/inspected less stringently for efficiency. A system for creating a reticle data file from an IC layout data file can include a processing module and a graphical display. The processing module can read the IC layout data file, identify critical features and define a halo region around each of the critical features. The graphical user interface can facilitate user input and control. The system can be coupled to a remote IC layout database through a LAN or a WAN.