Object table, lithographic apparatus and device manufacturing method

An object table system comprising:

• a support surface configured to support an object;
• and
• a lifting mechanism configured to displace the object from the support surface in a support direction substantially perpendicular to the support surface, the lifting mechanism comprising:
• one or more elongated rods, extending in the support direction, configured to support the object at a distance from the support surface, the one or more elongated rods being displaceable between a first position, wherein the one or more elongated rods are positioned below the support surface, and a second position, wherein the one or more elongated rods protrude from the support surface through one or more apertures of the support surface;
• a housing, at least partly enclosing the one or more elongated rods;
• an actuator configured to displace the one or more elongated rods between the first position and the second position;
• and
• a locking mechanism configured to limit a rotation about a longitudinal axis of the one or more elongated rods, the locking mechanism comprising a self aligning bearing, the self aligning bearing having a first member connected to the elongated rod and a second member, connected to the housing, co-operating with the first member to form the self aligning bearing, the first member comprising a first bearing surface and the second member comprising a second bearing surface;
• the first and second bearing surfaces being constructed and arranged to limit the rotation about the longitudinal axis of the one or more elongated rods, and wherein the first and/or second bearing surfaces is displaceable to provide self-alignment of the first bearing surface relative to the second bearing surface.

A device manufacturing method comprising:

• projecting a beam of radiation onto an object;
• and loading an object
• onto an object table using a lifting mechanism to displace the object relative to a support surface of the object table, the lifting mechanism comprising:
• one or more elongated rods, extending in a support direction substantially perpendicular to the support surface, supporting the object at a distance from the support surface, the one or more elongated rods being displaceable between a first position, wherein the one or more elongated rods are positioned below the support surface, and a second position, wherein the one or more elongated rods protrude from the support surface through one or more apertures of the support surface;
• an actuator displacing the one or more elongated rods between the first position and the second position;
• and
• a locking mechanism configured to limit a rotation about a longitudinal axis of the one or more elongated rods, the locking mechanism comprising an elastic element that is mechanically connected to both the one or more elongated rods and a housing that at least partly encloses the one or more elongated rods, the elastic element configured to have a comparatively low stiffness in the support direction and a comparatively high stiffness in a rotational direction about the longitudinal axis, wherein the elastic element comprises a leaf spring.