| 摘要 |
A heterodyne reflectometer system and method for obtaining phase shift information from heterodyned optical signals, from which film depths can be calculated A linearly polarized light comprised of two linearly polarized components that are orthogonal to each other, with split optical frequencies, is directed toward a film causing one of the optical polarization components to lag behind the other due to an increase in the optical path in the film for that component A pair of detectors receives the beam reflected from the film layer and produces a measurement signal, and the beam prior to incidence on the film layer and generates a reference signal, respectively The measurement signal and reference signal are analyzed by a phase detector for phase shift The detected phase shift is then fed into a thickness calculator for film thickness results A grating interferometer may be included with the heterodyne reflectometer system with a grating, which diffracts the reflected beam into zeroth- and first-order bands.
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