Apparatus and methods for keeping immersion fluid adjacent to an optical assembly during wafer exchange in an immersion lithography machine

A device manufacturing method in which a substrate is exposed with an exposure beam from a final optical element of a projection optical assembly and through an immersion liquid while the substrate is supported by a substrate table of a stage assembly, a confinement member encircling a portion of a path of the exposure beam and the confinement member having an aperture through which the exposure beam is projected, the method comprising:

• moving a movable member in a space between the confinement member and the substrate, the substrate table, or both, such that the space is divided into a first portion located between the confinement member and a first surface of the movable member, and into a second portion located between a second surface of the movable member and the substrate, the substrate table, or both,
• wherein the movable member is moved to a position at which a portion of the first surface of the movable member is located closer to an optical axis of the projection optical assembly than is an edge of the aperture.

A device manufacturing method in which a substrate is exposed with an exposure beam from a final optical element of a projection optical assembly and through an immersion liquid while the substrate is supported by a substrate table of a stage assembly, a confinement member encircling a portion of a path of the exposure beam and the confinement member having an aperture through which the exposure beam is projected, the confinement member having a lower surface that surrounds the aperture, the lower surface of the confinement member extending between an inner edge and an outer edge, the inner edge of the lower surface defining the aperture, the method comprising:

• moving a movable member in a space between the confinement member and the substrate, the substrate table, or both, such that the space is divided into a first portion located between the confinement member and a first surface of the movable member, and into a second portion located between a second surface of the movable member and the substrate, the substrate table, or both,
• wherein the movable member is moved to a position in which a portion of the first surface of the movable member is located farther from an optical axis of the projection optical assembly than is the outer edge of the lower surface of the confinement member.

A device manufacturing method in which a substrate is exposed with an exposure beam from a final optical element of a projection optical assembly and through an immersion liquid while the substrate is supported by a substrate table of a stage assembly, a confinement member encircling a portion of a path of the exposure beam and the confinement member having an aperture through which the exposure beam is projected, the confinement member having a lower surface that surrounds the aperture, the lower surface of the confinement member extending between an inner edge and an outer edge, the inner edge of the lower surface defining the aperture, the method comprising:

• moving a movable member in a space between the confinement member and the substrate, the substrate table, or both, such that the space is divided into a first portion located between the confinement member and a first surface of the movable member, and into a second portion located between a second surface of the movable member and the substrate, the substrate table, or both,
• wherein the movable member is moved to a position in which a portion of the second surface of the movable member is located farther from an optical axis of the projection optical assembly than is the outer edge of the lower surface of the confinement member.