IN-SITU OPTICAL MONITORING OF PULSED-LASER DEPOSITION OF YBA2CU3OX

In situ optical reflectometry at 670 nm has been used as a thickness monitor during the growth of YBa2Cu3Ox thin films. During deposition, the reflected signal showed damped oscillations due to interference and absorption in the growing film. The complex refractive index of the oxygen-depleted tetragonal phase, which exists at the high-temperature deposition conditions, was derived by fitting thickness variation of reflectivity to a three-layer calculation of the reflectivity. After deposition, as the film was cooled in oxygen, a further change of reflectivity was observed, which arises from the dependence of the refractive index on both the state of oxidation and temperature.