Calcium copper titanate, CaCu3Ti4O12 (CCTO), thin films have been fabricated by Metal Organic Chemical Vapor Deposition on silicon substrates buffered with two different low-k interlayers, namely SiO2 and Si3N4. Depositions have been carried out from a molten mixture consisting of the Ca(hfa)2 • tetraglyme, Ti(tmhd)2(O-iPr)2, and Cu(tmhd)2 [Hhfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; tetraglyme = 2,5,8,11,14-pentaoxapentadecane; Htmhd = 2,2,6,6-tetramethyl-3,5-heptandione; O-iPr = iso-propoxide] precursors. The chemical stability of CCTO films on both the SiO2 and Si3N4 low-k layers has been investigated by transmission electron microscopy in the perspective of their implementation in capacitor devices.