Patent Number: 051503913
Section: claims

1. An exposure apparatus for transferring a pattern of an original onto a workpiece, said apparatus comprising: a blocking member for defining a rectangular exposure region with respect to at least one of the original and the workpiece, wherein the exposure for the pattern transfer can be effected with the exposure region defined by said blocking member;  a plurality of detection systems for detecting a positional deviation between the original and the workpiece, each of said detection systems is disposed so as to be associated with at least one of four sides of the rectangular exposure region;  a plurality of first movable stages each being provided so as to be associated with at least one of the four sides, each of said first movable stages being adapted to carry thereon one of said detection systems disposed to be associated with a corresponding side, and each of said first movable stages comprises a single-axis stage movable in a direction parallel to a corresponding side; and  a plurality of second movable stages each for carrying thereon corresponding one of said first movable stages, each of said second movable stages comprising a single-axis stage movable in a direction perpendicular to a corresponding side and in a direction parallel to the rectangular exposure region, and each of said second movable stages being operable to displace said light blocking member to change the rectangular exposure region. 2. An apparatus according to claim 1, wherein each of said detection systems projects light to at least one of the original and the workpiece, and receives light reflected therefrom to detect the positional deviation. 3. An apparatus according to claim 2, wherein said light blocking member has a portion effective to block illumination light for the pattern transfer but to transmit light to be used for the detection of positional deviation by said detecting systems. 4. An apparatus according to claim 1, wherein said blocking member has a size sufficient for preventing impingement of scattered light, from the original, during the exposure, upon said detection systems. 5. An apparatus according to claim 1, wherein said detection systems, said first stages and said second stages are provided so as to be associated with the four sides, respectively.