Patent attributes
Exposure position marks are reliably recognized and the displacement of an exposure position is correctly and efficiently detected based on measurement results produced by recognizing the marks. The exposure position marks are constructed of a first pattern made up of an inner quadrangular pattern and an outer quadrangular pattern and a second pattern shaped as a rectangular frame whose inner edge and outer edge are formed as quadrangular patterns. The first pattern and the second pattern are formed with an intention of making center positions of the first pattern and the second pattern match and of having the second pattern disposed inside a region between an inner quadrangular pattern and an outer quadrangular pattern of the first pattern. The displacement of the exposure position is found by calculating an average of a measurement produced by detecting a displacement between the center positions of the inner quadrangular pattern of the first pattern and the quadrangular pattern that is the inner edge of the second pattern and a measurement produced by detecting a displacement between the center positions of the outer quadrangular pattern of the first pattern and the quadrangular pattern that is the outer edge of the second pattern.
