CVD of BSCCO

Fuflyigin VN, Kaul AR, Pozigun SA (1993) Effect of CVD process parameters on phase and chemical composition of BSCCO thin film. J Phys IV, 2, C3-361-366... 

Nemoto et al. at Nissan reported the first CVD growth of BSCCO films using fluorocarbon-based chelates [240]. Triphenyl bismuth and the hexafluoroacetylacetonato complexes of Sr, Ca, and Cu were used as precursors in oxygen at a 20 Torr system pressure with a substrate temperature of 600°C to give amorphous, insulating films. After an air anneal at 830°C for 1 h, the films were c-axis oriented Bi-2212 with 7(. = 50 K. Researchers at Advanced Technology Materials deposited amorphous BSCCO(F) films at 500 °C under 2 Torr pressure using the fluorinated complexes Ca(fod)2, Sr(fod)2, and Cu(hfa)2 as well as Bi(ph)3 as precursors [241]. Fluorine was... 

Uppsala and Northwestern University, thermodynamic calculations were performed using Bi(ph)3, Sr(hfa)itet, Ca(hfa)2tet, and Cu(acac)2 as metal-organic precursors [126]. The experimentally observed phase stability of BSCCO for in situ CVD was in agreement with the calculated thermodynamic oxide stability diagrams [126]. These results indicate that thermodynamic modeling can be used as a guide for the optimization of CVD routes to complex metal oxide films. 

Table 2-7. Experimental conditions for and superconducting properties of BSCCO thin films grown by CVD. 

Researchers at the University of Tokyo have reported the low temperature in situ growth of superconducting BSCCO films by CVD [238]. Bi(ph)j, Sr(dpm)2, Ca(dpm)2, and Cu(dpm)2 precursors were employed with oxygen at a substrate temperature of 550 °C and a system pressure of 2Torr, thereby producing Bi-2212 films with 7]. = 65 K. In another report, Bi-2212 phase films were grown at a deposition temperature of 500°C by UV-photo-assisted CVD, however, no superconducting transition was noted down to 15 K [239]. 

The synthesis of fluorinated, volatile bismuth )3-diketonates for MOCVD was reported in a recent submission by Sievers et al. [243]. Bi(fod),i was isolated and characterized to be sufficiently volatile for CVD growth of bismuth films although no BSCCO film growth has yet been demonstrated. This report also provides an excellent survey of volatile bismuth metal-organic and organometallic precursor chemistry. 

Zhang et al. at Northwestern University have reported the successful CVD growth of superconducting BSCCO films on polycrystalline silver substrates [247, 248]. After deposition at 625 °C using N2O as the reactant gas, the BSCCO precursor films were subjected to a flowing oxygen post-anneal at 650°C for 1 h, followed by 865°C for 1 h. Magnetically-derived Tj. values up to 80 K and zero-field values of 3.9 x 10 Acm" at 5.5 K were determined for these Bi-2212 phase films. 

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