| 摘要 |
PROBLEM TO BE SOLVED: To measure the phase difference of a phase shift film and the uniformity of the phase shift film at high speed. SOLUTION: A DUV(deep ultraviolet) laser beam is made into two-frequency orthogonal linearly polarized light R by a frequency shifter 14. This two- frequency orthogonal linearly polarized light R is separated by every polarized light component by a second polarization beam splitter 23. One of the light beams is transmitted through the entire surface of a photomask 10 and the other is passed through respective mirrors 25, 26 and again these light rays are synthesized again by a third polarization beam splitter 27. The interference light generated at this time is converted to an interference signal Q by a photodetector 29. The phase difference of the phase shift film 2 is determined from the phase difference between this interference signal Q and the reference signal (s). |
