Patent ID: 7229566
Filing Date: 2007-06-12
Classification: G03F

Abstract:
1. A position detection method for detecting a position of a substrate in a detection direction of a position detection mark substantially parallel to a surface of the substrate upon receiving light from the position detection mark formed in a shot on the surface of the substrate, comprising: an image information acquisition step of obtaining two-dimensional image information of the position detection mark from the light that has been received by an image sensor having a plurality of lines of which a plurality of pixels are arrayed in a detection direction of the position detection mark substantially parallel to the surface of the substrate and in a direction orthogonal to the detection direction; a conversion step of converting the image information to a plurality of light-intensity signals for each line of the plurality of lines, the plurality of light intensity signals being primary image signals obtained from the lights from different areas of a mark area in the shot in the direction of the position detection mark substantially parallel to the surface of the substrate and in the direction orthogonal to the detection direction; a determination step of determining whether the light-intensity signal of each line of the plurality of lines is valid or not; and a position information calculation step of calculating position information of the position detection mark from light-intensity signals of only valid lines other than light-intensity signals of invalid lines.