| 摘要 |
PROBLEM TO BE SOLVED: To obtain mutual position of a substrate with high accuracy and in a stable manner, relative to a reference point that faces the principal plane of the substrate. SOLUTION: A belt-shaped irradiation region on the principal plane 91 of a substrate 9, on which a linear pattern is formed is irradiated with light from a direction inclined to the direction of the normal line of the substrate 9. An imaging portion 42 receives reflection light and acquires an image containing the irradiation region on the principal plane 91. At pattern drawing, drawing light beam is emitted from a head portion 31 along with the movement of the substrate 9, and a summed image is acquired, by summing a plurality of images acquired at a plurality of positions on the principal plane 91. Average intensity distribution is acquired, by summing a plurality of pixel values in line the longitudinal direction at each position of the width direction of the irradiation region in the summed image. A light receiving position for the reflection light on an image taking surface 420, in a direction corresponding to the width direction of the irradiation region is specified, based on the average intensity distribution. As a result, the mutual position of the substrate 9, relative to a reference point can be obtained with high accuracy and stably by a trigonometrical survey method. COPYRIGHT: (C)2009,JPO&INPIT
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