Patent ID: 8830443

Claim:
A liquid immersion lithography apparatus comprising: a projection system having a final optical member; a liquid containment member that surrounds the final optical member of the projection system, a wafer being provided under the final optical member and under the liquid containment member, and the wafer being exposed through an immersion liquid in a first gap between the final optical member and the wafer, the liquid containment member including an open aperture through which the immersion liquid is allowed to move between a lower surface of the final optical member and an upper surface of the wafer, the final optical member is spaced from a portion of the liquid containment member having the open aperture such that a second gap exists between the portion of the liquid containment member having the open aperture and the final optical member; a porous member attached to the liquid containment member, through which the immersion liquid on a first side of the porous member is collected; and a space formed in the liquid containment member, the space being formed on a second side of the porous member which is opposite the first side of the porous member.