Patent ID: 7049592

Claim:
A lithographic projection apparatus, comprising: a radiation system constructed and arranged to provide a beam of radiation; a support constructed and arranged to support a patterning device, the patterning device constructed and arranged to pattern the beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; a base to which the support and the substrate table are mounted; and a reference frame compliantly mounted to the base, wherein the projection system comprises at least one optical element mounted on a projection frame that is compliantly mounted to the reference frame, wherein the project on system is compliantly mounted to the reference frame by at least one compliant mount, the compliant mount comprising a T-shaped member with one of the projection system and the reference frame attach to both ends of a first elongate member of the T-shaped member and the other of the projection system and the reference frame is attached to an end of a second elongate member of the T-shaped member.