IN-SITU SUBSTRATE-TEMPERATURE MEASUREMENT IN HIGH-TC SUPERCONDUCTING FILM DEPOSITION

An adaptively calibrated Pyrometer (ACP) is employed to measure the substrate surface temperature during the YBa2Cu3O7-delta film growth process. The film-thickness-dependent emittance of the film-substrate composite is determined from thin-film optics for instantaneous calibration of the pyrometer. The optical constants of the LaAlO3 substrate and the YBa2Cu3O7-delta film are measured at high temperatures using a Fourier transform infrared spectrometer with a special sample holder that controls the sample temperature and oxygen pressure. The accuracy and precision of the ACP are demonstrated through both in situ and ex situ measurements. The present study facilitates exact and reproducible temperature control in high-T(c) superconducting film growth processes.