The first atomic layer deposition process for FexN films†
An efficient process for ALD FexN films was reported in this study for the first time. Bis(N,N′-di-tert-butylacetamidinato)iron(II) (Fe(tBu-amd)2) and anhydrous hydrazine (N2H4) were used as reactants. Ideal self-limiting growth behavior was confirmed through the effect of the reactant dose and deposition cycle number on the growth rate (film thickness). Besides, these pure FexN films were able to grow into trench substrates with an aspect ratio of 2.5 : 1 conformally and uniformly, highlighting the potential of this ALD process for complex 3D or porous structures. The possible mechanism was proposed by investigating the reaction between Fe(tBu-amd)2 and N2H4 in toluene, and performing first-principles calculations. Our ALD process is expected to promote the development of FexN-based nanoengineering for its broad applications.