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

An adaptively calibrated Pyrometer (ACP) is employed to measure the su bstrate surface temperature during the YBa2Cu3O7-delta film growth pro cess. The film-thickness-dependent emittance of the film-substrate com posite is determined from thin-film optics for instantaneous calibrati on of the pyrometer. The optical constants of the LaAlO3 substrate and the YBa2Cu3O7-delta film are measured at high temperatures using a Fo urier transform infrared spectrometer with a special sample holder tha t controls the sample temperature and oxygen pressure. The accuracy an d precision of the ACP are demonstrated through both in situ and ex si tu measurements. The present study facilitates exact and reproducible temperature control in high-T(c) superconducting film growth processes .