A stack of a second photoresist having a second photosensitivity and a first photoresist having a first photosensitivity, which is greater than second photosensitivity, is formed on a substrate. A first pattern is formed in the first photoresist by a first exposure and a first development, while the second photoresist underneath remains intact. A second pattern comprising an array of lines is formed in the second photoresist. An exposed portion of the second photoresist underneath a remaining portion of the first photoresist forms a narrow portion of a line pattern, while an exposed portion of the second photoresist outside the area of the remaining portions of the photoresist forms a wide portion of the line pattern. Each wide portion of the line pattern forms a bulge in the second pattern, which increases overlay tolerance between the second pattern and the pattern of conductive vias.