Patent ID: 8243253

Claim:
An apparatus comprising: a support that supports a workpiece; an optical assembly that projects an image onto an upper surface of the workpiece through an immersion liquid filled in a gap between the optical assembly and a part of the upper surface of the workpiece such that the immersion liquid covers only an area smaller than an area of the upper surface of the workpiece; and a stage assembly that is movable relative to the optical assembly, the stage assembly including the support, a drop-down region, a lyophobic region and a collection region, the stage assembly being capable of collecting the immersion liquid through the drop-down region, the lyophobic region and the collection region, wherein the drop-down region continuously encircles the support, the lyophobic region includes a lyophobic surface that continuously encircles the support and a circumference of the workpiece supported by the support, the collection region from which the immersion liquid is collected from the lyophobic region includes an opening that is disposed below a bottom surface of the workpiece supported by the support and radially outward of the circumference of the workpiece, and the collection region encircles both the drop-down region and the lyophobic surface.