Atomic layer deposition of lanthana thin films using high-purity lanthanum amino precursors

Lanthana (La2O3) thin films were grown by atomic layer deposition using the homoleptic amino precursor La[N(TMS)2]3. This volatile metal-organic was synthesized on a large scale using commercially available lanthanum triflate (La(OTf)3) and the amino was recovered in excellent yields and high analytical purity. La2O3 thin films (∼25 nm) were grown on p-type (1 0 0) silicon substrates using a hot-wall ALD reactor at 300 °C and exhibit smooth, featureless surfaces with rms roughnesses of 2.5 nm. PXRD indicates that the existing lanthana crystallites can be indexed in the hexagonal system.