In-situ gas-phase FTIR monitoring of MOCVD processes: LaF3 films using thesecond generation La(hfac)(3)center dot diglyme precursor

In-situ gas-phase Fourier transform infrared spectroscopy (FTIR) studies of thermally activated processes occurring in the metal-organic chemical vapo r deposition (MOCVD) of La(hfac)(3).diglyme provide evidence that the precu rsor can be evaporated from the melt up to 130 degrees C without side decom position processes. In contrast, under typical operating conditions in hot- wall MOCVD processes, the precursor undergoes different demolition pathways . Under Ar, it is stable up to 300 degrees C. At higher temperatures, decom position involves the beta-diketonate array leaving the glyme coordination intact. Materials thus deposited have greater carbon contamination, Introdu cing O-2 into the stream promotes diglyme dissociation and prevents carbon contamination in the film. Thermally activated processes show close analogi es with those of the free Hhfac ligand. Fluorinated ketones and acylketenes are formed as the main decomposition products. Complementary insights into the factors responsible for the contamination associated with the depositi on processes have been obtained by X-ray photoelectron spectroscopy (XPS) s tudies.