Pressure and Temperature Effects on Stoichiometry and Microstructure of Nitrogen‐Rich TiN Thin Films Synthesized via Reactive Magnetron DC‐Sputtering

Abstract

Nitrogen‐rich titanium nitride (TiN) thin films containing excess nitrogen up to 87.0 at.% were produced on (100) Si substrates via the reactive magnetron DC‐sputtering of a commercially available 99.995 at.% pure Ti target within an argon‐nitrogen (Ar‐N 2 ) atmosphere with a 20‐to‐1 gas ratio. The process pressure ( P P ) and substrate temperature ( T S ) at which deposition occurred were varied systematically between 0.26 Pa–1.60 Pa and between 15.0 ∘ C–600 ∘ C, respectively, and their effects on the chemical composition, surface morphology, and preferred orientation were characterized by energy dispersive X‐ray spectroscopy (EDS), field emission scanning electron microscopy (FE‐SEM), and X‐ray diffraction (XRD). The EDS analysis confirms increasing nitrogen content with increasing P P and T S . The SEM images reveal a uniform and crystallized surface morphology as well as a closely packed cross‐sectional morphology for all crystalline films and a loosely packed cross‐sectional morphology for amorphous films. Films produced at lower P P and T S have a pyramidal surface morphology which transitions to a columnar and stratified structure as P P and T S increase. The XRD analysis confirms the existence of only the δ ‐TiN phase and the absence of other nitrides, oxides, and/or sillicides in all cases. It also indicates that at lower P P and T S , the preferred orientation relative to the substrate is along the (111) planes, and that it transitions to a random orientation along the (200), (220), and (311) planes as P P and T S increase and these results correlate with and qualify those observed by SEM.