CVD of Lanthanum Oxyfluoride-Based Thin Films from a Lanthanum β-Diketonate Diglyme Precursor

Abstract

Lanthanum oxyfluoride-based thin films were grown on SiO2 and Si(100) by CVD from La(hfa)3·diglyme (Hhfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; diglyme = bis(2-metoxyethyl)ether), acting as the source for both lanthanum and fluorine. Film syntheses were performed in an atmosphere of nitrogen + wet oxygen, with particular attention paid to the structural and compositional evolution as a function of the deposition temperature (200–500 °C). To this aim, specimens were subjected to a multi-technique characterization by means of glancing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and atomic force microscopy (AFM). The formation of nanophasic (crystallite size < 30 nm) films containing LaOF, with a cleaner precursor conversion at the highest deposition temperatures, is evidenced and discussed, highlighting the most critical parameters for obtaining lanthanum oxyfluoride coatings with controlled properties.