Patent ID: 9632431
Date: 2017-04-25
CPC Classifications: G03F,Y10T

Claim:
1. A positioning apparatus for use in an immersion lithographic apparatus that projects a patterned beam of radiation onto a substrate via an optical member and via a liquid under the optical member, the positioning apparatus comprising: a first table connected to a first positioning system configured to displace the first table into and out of a path of the patterned beam of radiation, the first table being arranged facing a base member and configured to hold the substrate; a second table connected to a second positioning system configured to position the second table into the path of the patterned beam of radiation when the first table is displaced out of the path of the patterned beam of radiation, the second table being arranged facing the base member and not being configured to hold any substrate and including a top surface in which a surface of a sensor configured to sense a property of the patterned beam of radiation via the liquid is arranged, the second table, at least during the projection of the patterned beam of radiation via the optical member and via the liquid onto the substrate held on the first table, being away from the first table and being independently movable relative to the first table; and a controller connected to the first and second positioning systems, which controls the first and second positioning systems such that the first table and the second table are moved relative to the optical member while the first table and the second table are close to each other and while the first table and the second table are facing the base member during a replacing operation of the first and second tables to move the first table out of the path of the patterned beam of radiation and move the second table into the path of the patterned beam of radiation while the first table and the second table are supported above an upper surface of the base member, wherein