Elaboration of Ta2O5 Thin Films Using Electrostatic Spray Deposition for Microelectronic Applications

The deposition of tantalum oxide thin films on SiO x N y /Si substrates using electrostatic spray deposition was investigated. Different microstructures (dense, reticulated, porous) depending on the process parameters such as the nature of the precursor solution, substrate temperature, nozzle-to-substrate distance, and precursor solution flow rate were obtained. The evolution of film thickness and morphology versus deposition time was discussed. The films deposited at temperatures ranging from 100 to 210 °C were found amorphous. A pure pseudo hexagonal δ-Ta2O5 single phase was identified by X-ray diffraction and Raman spectrocopy after annealing from 650 °C and above.