A study of high NA EUV pattern stitching using rigorous stochastic lithography simulation

Anamorphic magnification in high NA EUV will reduce the maximum wafer area of a single lithographic exposure field in half compared to current exposure equipment. Large die exceeding this area will require the use of two separate masks which must be stitched together. There is a preference within the industry to stich the fields together "at resolution" using features of the same dimension and pitch as those elsewhere in the design. Stochastic lithography simulation is used to model the effects of field stitching on patterning performance with regards to the defectivity process window as a function of X and Y registration. It is observed that the best defectivity performance conditions may vary significantly from those that produce the optimum CD uniformity.