Embodiments of the present disclosure relate to methods for positioning masks in a propagation direction of a light source. The masks correspond to a pattern to be written into a photoresist layer of a substrate. The masks are positioned by stitching a first mask and a second mask. The first mask includes a set of first features having first feature extensions extending therefrom at first feature interfaces. The second mask includes a set of second features having second feature extensions extending therefrom at second feature interfaces. Each first feature extension stitches with each corresponding second feature extension to form each stitched portion of a first stitched portion of the first pair of masks. The stitched portion of the first pair of masks defines a portion of the pattern to be written into the photoresist layer.