Patent ID: 7084961

Claim:
A lithographic apparatus comprising: an illumination system for providing a beam of radiation; a support structure for supporting a patterning device that serves to impart said beam of radiation with a pattern in its cross-section; a substrate holder for holding a substrate having a plurality of target portions; a projection system for projecting said patterned beam onto said substrate target portions; a positioning system for positioning said patterning device relative to said support structure; a connector for securing said patterning device relative to said support structure; a safety mechanism configured to contain displacement of said patterning device in case of failure of said connector; and a lithographic operational cycle, comprising: a projection phase in which, while said patterned beam is projected onto a target portion of the substrate, said patterning device is secured to said support structure by said connector, and an exchange phase, in which said patterning device is exchanged, said positioning system positions said patterning device relative to said support structure, and at least a part of said positioning system is withdrawn after said patterning device has been positioned, wherein said safety mechanism is configured to contain said patterning device in case of failure of said connector at least during the projection phase.