A CW CO2-LASER SUBSTRATE HEATER FOR SUPERCONDUCTING THIN-FILM DEPOSITION

Single-crystal MgO and SrTiO3 substrates have been raised to temperatures suitable for deposition and in situ annealing of high-Tc superconducting thin films by the absorption of 10.6 mu m laser radiation. Steady-state temperature control in vacuum and low-pressure oxygen was achieved by varying the mark-space ratio of the RF-excited CO2 laser heater source. This approach allows high temperatures (>or=950 K) to be achieved with relatively low power input (or=30 W) and maintains deposition chamber cleanliness. © 1990 IOP Publishing Ltd.