Low-temperature MOCVD of Epitaxial CaF2 and SrF2 Films

Abstract

The deposition of epitaxial CaF2 and SrF2 thin films on (00l)SrTiO3 substrates and textured Ni-W-alloy tapes by low-temperature water assisted MOCVD was studied. Complexes Ca(hfa)2(diglyme)(H2O) and Sr(hfa)2(tetraglyme) (Hhfa = 1,1,1,5,5,5-hexafluoroacetylacetone, diglyme = 1-methoxy-2-(2-methoxyethoxy)ethane, tetraglyme = 2,5,8,11,14-pentaoxapentadecane)) were used as single-source precursors. It was observed that the water presence increased the deposition rate and reduced the activation energy of film deposition process at temperature below 500oC. To estimate a role of water in thermal decomposition of Ca(hfa)2(diglyme) vapor on a heated surface, high temperature mass spectrometry in a vacuum was used. The quality of films was analyzed with XRD, AFM, SEM and EBSD methods. The results obtained may be useful for technology development of high temperature superconducting wires, optical and microelectronic devices.