Growth of the Initial Atomic Layers of Ta‐N Films During Atomic Layer Deposition on Silicon‐Based Substrates

Abstract

Abstract The growth of ultra‐thin Ta‐N films using atomic layer deposition (ALD) is investigated by in‐situ X‐ray photoelectron spectroscopy (XPS) starting from the first precursor pulse, as precursor substances tert ‐butylimido‐tris(diethylamido)tantalum (TBTDET) and tert ‐butylimido‐bis(diethylamido)cyclopentadienyl)tantalum (TBDETCp) are applied mainly on SiOH and SiH surfaces. The chemical composition, the growth mode, and the film thickness are derived as functions of the cycle number and the substrate chemistry. The growth rates are significantly higher on SiOH than on SiH substrates, which is related to the oxygen surface concentration. The film composition changes with the cycle number but stabilizes at an approximate stoichiometry of Ta 2 N 2 O for both precursors.