CPC G03F 7/70341 (2013.01) [G03F 7/70725 (2013.01)] | 20 Claims |
1. An immersion lithography apparatus comprising:
a support table configured to support an object having at least one target portion;
a projection system configured to project a patterned beam onto the object;
a positioner configured to move the support table relative to the projection system;
a liquid confinement structure configured to confine a liquid to an immersion space between the projection system and a surface of the object and/or of the support table, using a fluid flow into and/or out of the liquid confinement structure through a series of openings formed in the liquid confinement structure; and
a controller configured to control the positioner to move the support table to follow a route comprised of a series of motions and to control the liquid confinement structure wherein each motion involves the support table moving relative to the liquid confinement structure such that a portion of the support table which moves from being not under the liquid confinement structure to being under the liquid confinement structure passes under a leading edge of the liquid confinement structure and a portion of the support table which moves from being under the liquid confinement structure to being not under the liquid confinement structure passes under a trailing edge of the liquid confinement structure, the controller configured to:
predict whether the liquid will be lost from the immersion space during at least one motion of the series of motions in which an edge of the object passes under an edge of the immersion space, and
if liquid loss from the immersion space is predicted, to modify the fluid flow such that a first fluid flow rate into or out of an opening of the series of openings at the leading edge of the liquid confinement structure is different to a second fluid flow rate into or out of an opening of the series of openings at the trailing edge of the liquid confinement structure during the motion of predicted liquid loss or a motion of the series of motions subsequent to the motion of predicted liquid loss.
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