Patent ID: 7511826
Filing Date: 2009-03-31
Classification: G03F

Abstract:
1. A system for producing an adjusted light beam prior to an interaction between the adjusted light beam and a substrate, comprising: an interferometer configured to receive a light beam, the light beam produced from a light source or from combining beams from a plurality of light sources, to split the received light beam into first and second beams, to rotate the first beam with respect to the second beam about an axis of rotation, such that, when recombined, the first and second beams have 180 degree symmetry about the axis of rotation, and to recombine the first and second beams to form the recombined beam; a compensator configured to adjust path lengths of either the combined light beam or the recombined beam in first and second polarization directions to form the adjusted light beam, such that the path lengths in each of the first and second polarization directions are substantially equal; and an analyzer configured to pass a polarization direction or an amplitude and phase profile of the recombined light beam or a polarization direction or an amplitude and phase profile of the adjusted light beam, wherein the adjusted light beam is directed onto the substrate.