An apparatus of manufacturing a semiconductor device is provided. The apparatus including a controller configured to: expose a first region of a photoresist layer with a light pattern, expose a second region of the photoresist layer with at least in part the same light pattern, wherein the second region and the first region overlap in an overlap region of the photoresist layer, and wherein light pattern is configured to form, in exposing the first region, a first portion of individual markings in the overlap region of the photoresist layer, and to form, in exposing the second region, a second portion of individual markings in the overlap region of the photoresist layer. By measuring the composite pattern formed in photoresist by overlapping the first exposure with the second exposure, the relative position of the two exposures can be determined and controlled.