Environmental system including a transport region for an immersion lithography apparatus

Abstract

An immersion lithography apparatus includes: an optical assembly including a plano-convex lens as a last optical element, the optical assembly configured to project an image onto a substrate through an immersion liquid; a containment member that surrounds a last portion of the optical assembly, the containment member having a channel via which the immersion liquid recovered from a gap between the containment member and the substrate and/or a stage holding the substrate is removed; an outlet above a bottom surface of the last optical element, via which the immersion liquid is released to a space between the optical assembly and the containment member; and an immersion liquid source apparatus from which the immersion liquid is delivered to the outlet, the immersion liquid source apparatus having a flow controller, and a flow sensor that measures a rate of a flow of the immersion liquid to be delivered to the outlet.

What is claimed is: 
     
         1 . An immersion lithography apparatus comprising:
 an optical assembly including a last optical element which is a plano-convex lens, the optical assembly configured to project an image onto a substrate through an immersion liquid;   a containment member arranged to surround a last portion of the optical assembly, the containment member having a channel via which the immersion liquid recovered from a gap between the containment member and the substrate and/or a stage holding the substrate is removed;   an outlet arranged above a bottom surface of the last optical element, via which the immersion liquid is released to a space between the optical assembly and the containment member; and   an immersion liquid source apparatus from which the immersion liquid is delivered to the outlet, the immersion liquid source apparatus having a flow controller, and a flow sensor that measures a rate of a flow of the immersion liquid to be delivered to the outlet.