| 摘要 |
PURPOSE:To measure the position of a substrate stage to a mask placed on a carriage accurately at all times without being affected by the positional factor of the carriage by mounting a laser interference generating section for detecting displacement in at least two directions onto a scanning means scanning an original plate and a body to be exposed to an exposure means. CONSTITUTION:A laser interference generating section 16 for detecting displacement in at least two directions of an original plate 1 or a body to be exposed 3 is set up onto a scanning means relatively scanning the original plate 1 and the body to be exposed 1 to an exposure means. Beams from a laser tube 14 are reflected by a mirror 33, and divided by a half mirror 22a, and reflected beams are directed toward an interference section 16a for detecting displacement in the X direction. Transmitting beams are divided by a half mirror 22b through a mirror 23a, and reflected beams are directed toward an interference section 16b for detecting displacement in the Y direction. Transmitting beams are projected to an interference section 16c for detecting displacement in the thetadirection through a mirror 23b. A detector 20 detects the change of intensity of beams, and displacement in each direction and a current position are computed by CPU 30. |
