| 摘要 |
<p>Nondestructive characterization of each of the layers (dn of a multilayer thin film structure (25) is obtained by directing a first beam of radiation (40) into an optical coupler (37) having a base (38) in contact with the surface of the structure (25). The angle of the beam entering the coupler is such that the beam is reflected from the base with an evanescent wave component passing from the coupler and coupling into the multilayer thin film structure as a real beam. The real beam is reflected from the layers of the thin film structure (25) back in the coupler (37) where it combines with the beam (51) reflected from the base and exits the coupler with an intensity related to the characteristics of the structure layers. A servo motor (46) rotates the coupler to scan the first beam therein and a detector (50) detects the intensity of the combined beams exiting the coupler during the scanning thereof by the first beam. A computer (60) compares the detected reflectance intensity sensed by the detector with the reflectance intensity of structures having known characteristics to determine the characteristics of the multilayer thin film structure (25).</p> |
