Patent ID: 7193722

Claim:
A lithographic projection apparatus, comprising: a first exposure system having at least one movable part, said at least one movable part being located within a housing, said housing including an additional movable part that is movable by a second control unit, said first exposure system including: (i) a radiation system configured to provide a beam of radiation; (ii) a support structure configured to support a patterning device that serves to impart the beam of radiation with a pattern in its cross-section; (iii) a first substrate holder for holding a substrate; (iv) a projection system configured to project the patterned beam onto a target portion of said substrate; (v) a positioning device configured to position said first substrate holder relative to said projection system; (vi) a first control unit configured to control said positioning device; and (vii) a position disturbance correction system constructed to counteract a disturbance of a position of said first substrate holder, wherein the disturbance is caused by gas movements induced by movement of said at least one movable part, wherein, when a distance between said first substrate holder and said additional movable part is less than a predetermined minimum distance value, said position disturbance correction system being configured to reduce a speed and/or an acceleration of said additional movable part to a respective speed value and/or acceleration value, in which the respective speed value and/or acceleration value is less than a predetermined maximum speed value and/or maximum acceleration value.