Abstract: A reticle, for use in a stepper, and a method for using the reticle are provided. The reticle is used in performing the method for inspecting for the leveling of the reticle with respect to a semiconductor wafer being exposed by the stepper. Reticle alignment marks are used to measure reticle leveling by determining the degree of resolution at several sites on the semiconductor workpiece. The reticle can be patterned with a plurality of sets of alignment marks having an array of blocks which are in focus at different focal lengths. The alignment marks include marks located proximate to the corners of the reticle and proximate to the center of the reticle. Microscope measurements are made to determine the focal length at each set of alignment marks. Reticle pitch is determined at each workpiece position from the focal lengths measured at each alignment mark. The leveling can be checked repeatedly to obtain information for producing optimum focus of the reticle image on the workpiece.

Abstract: A reticle, for use in a stepper, and a method for using the reticle are provided. The reticle is used in performing the method for inspecting for the leveling of the reticle with respect to a semiconductor wafer being exposed by the stepper. Reticle alignment marks are used to measure reticle leveling by determining the degree of resolution at several sites on the semiconductor workpiece. The reticle can be patterned with a plurality of sets of alignment marks having an array of blocks which are in focus at different focal lengths. The alignment marks include marks located proximate to the corners of the reticle and proximate to the center of the reticle. Microscope measurements are made to determine the focal length at each set of alignment marks. Reticle pitch is determined at each workpiece position from the focal lengths measured at each alignment mark. The leveling can be checked repeatedly to obtain information for producing optimum focus of the reticle image on the workpiece.