In the present study, novel AlCoCrNi high entropy nitride (HEN) films were deposited on Si substrate by a reactive direct current magnetron sputtering system. In order to investigate the influence of sputtering parameters on the microstructure and mechanical properties of the film, nitrogen flow ratio (R_N: 25–100%) and process pressure (1.33 × 10⁻¹–1.33 Pa) were controlled, respectively. All the films were identified as an amorphous phase with composition of near equiatomic ratios, regardless of the conditions of nitrogen flow ratios and process pressures. However, the limited mechanical properties were found for the films deposited under different nitrogen flow ratios with retaining the process pressure of 1.33 Pa. To enhance the mechanical properties of the AlCoCrNi HEN film, process pressure was adjusted. From the transmission electron microscopy (TEM) observation, the structure of the film deposited at the process pressure of 1.33 Pa is identified as a porous and open structure with a number of density-deficient boundary and nano-scale voids. On the other hand, densified morphology of the film was observed at pressure of 1.33 × 10⁻¹ Pa. As a result, the hardness, elastic modulus, and H/E were improved up to 16.8, 243 GPa, and 0.0692, respectively.

In this study, Mo–Si–N coatings were deposited on Si wafers and tungsten carbide substrates using a reactive direct current magnetron sputtering system with a MoSi powder target. The influence of sputtering parameters, such as the N₂ gas flow ratio and working pressure, on the microstructure and mechanical properties (hardness (H), elastic modulus (E), and H/E ratio) of the Mo–Si–N coatings was systematically investigated using X-ray diffractometry (XRD), scanning electron microscopy (SEM), nanoindentation, and transmission electron microscopy (TEM). The gas flow rate was a significant parameter for determining the crystallinity and microstructure of the coatings. A Mo₂N crystalline coating could be obtained by a high N₂ gas flow ratio of more than 35% in the gas mixture, whereas an amorphous coating could be formed by a low N₂ gas flow ratio of less than 25%. Furthermore, the working pressure played an important role in controlling the smooth surface and densified structure of the Mo–Si–N coating. For the amorphous Mo–Si–N coating deposited with the lowest working pressure (1 mTorr), the hardness, elastic modulus, and H/E ratio reached from 9.9 GPa, 158.8 GPa, and 0.062 up to 17.9 GPa, 216.1 GPa, and 0.083, respectively.