Patent ID: 7177059
Filing Date: 2007-02-13
Classification: G03F

Abstract:
1. A lithographic apparatus, comprising: an interferometric system including a radiation source that generates a metrology beam; a first optical wedge; a second optical wedge, said first and second optical wedges having a relative position with respect to each other, wherein the first and second optical wedges are configured to rotate around a rotation axis that is perpendicular to an optical axis; wherein at least a portion of said metrology beam propagates along an incoming optical axis at a first major surface of said first optical wedge, passes through said first and second optical wedges, and exits at a second major surface of said second optical wedge, and wherein said first and second optical wedges are configured to perform at least one of a rotation and a translation of at least the portion of said metrology beam relative to said incoming optical axis by changing said relative position of said first and second optical wedges.