Patent ID: 9329492
Filing Date: 2016-05-03
CPC Classification: G03B,G03F

Claim Text:
1. An immersion liquid confinement apparatus for confining an immersion liquid in an immersion area that includes a gap between a projection system and an object in an immersion lithography system, the apparatus also recovering the immersion liquid from the immersion area, the apparatus comprising: an aperture through which a patterned image is projected; an outlet that faces downwardly so that the outlet faces the object, the outlet located radially outward of an outer circumference of the aperture relative to an optical axis of the projection system; a first chamber into which the immersion liquid is recovered through the outlet; and a second chamber into which the immersion liquid is recovered through a porous member from the first chamber, wherein: the porous member has a first surface contacting the first chamber and a second surface contacting the second chamber, and a vertical position of a first portion of the first surface is different from a vertical position of a second portion of the first surface.