Deposition and characterization of NiAl and Ni–Al–N thin films from a NiAl compound target

NiAl and Ni–Al–N thin films have been deposited from a dense and homogeneous NiAl compound target onto various substrates, including stainless steel, glass, and Si100 wafer, by using RF magnetron sputtering. The films have been characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Auger electron spectroscopy, scanning electron microscopy, and scanning transmission electron microscopy. Both the NiAl and Ni–Al–N thin films exhibited the near equiatomic NiAl phase. The Ni–Al–N thin films showed an increasing nitrogen content with increasing the amount of N2 in the sputtering atmosphere during deposition. XPS spectra confirmed the possible formation of aluminum nitride in the Ni–Al–N films. The texture, composition, and microstructure of the NiAl films change with the discharge power used. The NiAl thin films deposited using 500 W RF power exhibited the microstructure of a 0.5–0.7-μm amorphous layer adjacent to the substrate and a dense and columnar zone T crystalline microstructure which had a preferred orientation [110]. The Ni–Al–N films showed a homogeneous microstructure of very fine (nano scale) NiAl (110) grains distributed into an amorphous matrix. The results confirm the feasibility of producing high-quality NiAl and Ni–Al–N thin films from a NiAl compound PVD target.