MOCVD of Ni and Ni3C films from Ni(dmen)2(tfa)2

Abstract

In this study results are reported on the transport and decomposition behavior of a trifluoroacetato complex of formula Ni(dmen) 2 (tfa) 2 , in view of its use as a precursor for the MOCVD of Ni. It is shown that Ni(dmen) 2 (tfa) 2 can be sublimed up to 190 °C without decomposition with, however, a relatively low partial pressure MOCVD of Ni films from this precursor on silicon and on silica are also reported, performed at temperatures varying between 275°C and 350°C. It was found that the process is kinetically controlled. Films are crystalline, present a granular morphology and, depending on operating conditions, are composed of Ni, of metastable nickel carbide Ni 3 C or of mixtures thereof. The carbon content decreases with decreasing deposition temperature and with increasing hydrogen flow rate. It is also higher in the first deposited layers, revealing a different decomposition mechanism of the precursor on an inert relatively to a metallic surface. Although processing conditions have not been optimized, MOCVD of Ni films from this family of complexes appears promising, However, modifications of the structure of Ni(dmen) 2 (tfa) 2 are necessary to increase its volatility and consequently the growth rate of the films.