Fabrication of high-temperature superconducting thin films (Y-Ba-Cu-0, Bi-Sr-Ca-Cu-0, TI-Ba-Ca-CbO systems) by chemical vapour deposition (CVD) is reviewed. The key to the use of the CVD method is to find volatile compounds for the metallic constituents of superconductors. /?diketonate complexes such as acetylacetonates and dipivaloyimethanates have been successfully used as source materials. The quality of the films grown is affected by the deposition temperature, substrate material and postdeposition annealing procedure. Considerable progress has recently been made and the critical properties of cvD-grown films are now equal to those of physical vapour-deposited films.

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Yttrium oxide thin films were deposited in a flow‐type ALE reactor from Y(thd)3 (Hthd  2,2,6,6‐tetramethyl‐3,5‐heptanedione) and either ozone or oxygen. The influence of the substrate and source temperatures, pressure and pulse durations on the film growth on soda‐lime and silicon substrates was studied. Films were also grown on Corning glass, sapphire and Si/CeO2 substrates to study the effect of the substrate on the growth rate and crystallinity of the films. Spectrophotometry, XRD and AFM were used to determine the optical properties, thickness, crystallinity and surface morphology of the films. All the films deposited with ozone were crystalline, but differences in preferential orientation depending on the substrate were observed. The growth rate with ozone was about 0.8 Å cycle−1 on all substrates except sapphire where it was higher. The films deposited with oxygen were less crystalline and the growth rate was significantly lower than in depositions with ozone under the same growth conditions.

CeO 2 overlayers up to 360 nm thick were deposited on Si(100) substrates in a flowtype ALE reactor from Ce(thd) 4 (thd = 2,2,6,6-tetramethyl-3,5-heptanedione) precursor and ozone. The growth rate was studied as a function of deposition and source temperatures, reactor pressure and pulse durations. The films were characterized for crystallinity, thickness and composition by using XRD, profilometry, XRF, RBS, XPS and SIMS techniques. Films deposited at 375 OC showed a preferential (110) orientation while at 425 1C they were (111) preferentially oriented. Due to the steric hindrance caused by the bulky precursor the growth rate was only 0.4 A/cycle.