Radiative Substrate Heating for High-T(c) Superconducting Thin-Film Deposition:Film-Growth-Induced Temperature Variation. (Reannouncement with New Availability Information)

摘要

We have examined the problem of substrate temperature changes during the growthof YBa2CU307-x (YBCO) thin films on LaA103 when the substrate is radiatively heated. Substrate temperature variations sufficient to degrade film quality occur unless the heater temperature is controlled during growth. At a heater temperature of 900 deg C, the temperature of a LaAlO3 substrate was measured to be only 540 deg C, while a similar substrate with a 2000-A YBCO film reached 640 deg C. The experimental data and calculations indicate that the heater temperature must be as high as 1240 deg C to heat LaAlO3 to 730 deg C, and must be decreased by over 200 deg C during the first 500 A of film deposition to maintain a constant substrate temperature during film growth. This study shows the need for an in situ noncontact substrate temperature measurement technique.... Substrate heating, Superconductivity, Superconducting thin-film.