Patent ID: 6900879

Claim:
A scanning exposure apparatus which transfers a pattern in a rectangular area defined by a light shielding border on a first object onto a photosensitive second object through a projection system by synchronously moving the first and second objects, comprising: an illumination system, including an optical integrator and an optical system provided on an optical axis common to said projection system, which illuminates a region perpendicular to the optical axis with a radiation from the optical integrator through the optical system so that the radiation is generated on said first object moved in a scan direction during a scanning exposure of said second object with the radiation from said first object through said projection system by said synchronous movement; and a masking blade provided between said optical integrator and said optical system to be movable in a predetermined direction on a plane perpendicular to said optical axis, which has a pair of edges substantially parallel to each other and perpendicular to the predetermined direction in the plane, and is moved so that the pair of edges are respectively imaged at a beginning and an end of said scanning exposure onto said light shielding border by said optical system to change a width of said illuminated region with respect to said scan direction at both the beginning and the end of said scanning exposure.