Effects of Negative Bias Voltage and Ratio of Nitrogen and Argon on the Structure and Properties of NbN Coatings Deposited by HiPIMS Deposition System

Abstract

The NbN x>1 coatings were deposited on Si wafer and SUS 304 stainless steel substrates by a high power impulse magnetron sputtering (HiPIMS) system at various bias voltages and the ratios of nitrogen and argon (N 2 /Ar). By virtue of electron probe microanalysis (EPMA), X-ray diffraction pattern (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and nano indentation test, the relationships between deposition parameters and coatings properties were examined in detail. These coatings show a strong preferred orientation of (200) plane at free bias voltage. With increasing bias voltage, the intensity of (200) plane peak became weaker and the full width at half maximum of peaks ((200) and (111) peaks) became broader, implying the crystalline grain size were decreased. The (200) plane almost is disappeared at −150 V bias voltage and the phase transition maintains the same change tendency with the increase of N 2 /Ar gas ratio. The coating microstructure gradually evolved from coarse columnar to dense columnar, and then to compact featureless structure with increase of the bias voltage, corresponding to the decreased surface roughness. The columnar structure of coatings is unrelated to N 2 /Ar gas ratio and the thickness is minimum at high N 2 /Ar ratio, which is attributed to the poor sputtering capability of nitrogen compared with argon instead of target poisonous effect. The higher hardness (H) and elastic recovery value are obtained for NbN x>1 (H = 31.3 GPa and W e = 69.2%) at −150 V bias voltage, suggesting considerable influence of bias voltage on hardness than that of the N 2 /Ar gas ratio.

Surface modification of AISI-420 steel by cathodic cage plasma niobium nitride deposition

“…Barshilia et al 13 used DC planar magnetron sputtering to deposit niobium nitride coating on tool steel and obtained a hardness of 17 GPa. Totik 14 12 reported high-power impulse magnetron sputtering to deposit niobium nitride on SUS-304 SS and obtained a hardness of up to 31.3 GPa. This comparison reveals the CCPD technique can obtain effective improvement in hardness.…”

“…They found improvement in hardness up to 1084, 2040, and 2620 HK 25 for MS, SS, and HSS, respectively. Ding et al 12 examined the role of negative bias voltage on the surface properties of niobium nitride on SUS-304 SS deposited by high-power impulse magnetron sputtering. They observed that increasing the biasing voltage could improve hardness up to 31.3 GPa.…”

“…These coatings are extensively reported by numerous techniques, including reactive pulsed laser deposition, 7 multi-arc ion plating, 8 cathodic arc physical vapour deposition, 9 thermo-reactive deposition process, 10 direct current (DC)/pulsed DC magnetron sputtering, 11 and high-power impulse magnetron sputtering. 12 Barshilia et al 13 reported the deposition of TiN, NbN, and multilayer coating on tool steel using DC planar magnetron sputtering. They improved hardness up to 23 and 17 GPa by individual coating and 38 GPa by multilayer coating.…”

Ta/TaN Multilayer Thin Film Coatings with HiPIMS Technique for Tribological Applications

“…It has been previously reported that this preferred orientation in TaN films has a positive influence on hardness as shown in Table 1. However, when the nitride ratio in the film exceeds 5%, the preferred orientation shifts from hexagonal-Ta2N structure to cubic-TaN structure, subsequently leading to a decrease in hardness [14].…”

“…It has been previously reported that this preferred orientation in TaN films has a positive influence on hardness as shown in Table1. However, when the nitride ratio in the film exceeds 5%, the preferred orientation shifts from hexagonal-Ta2N structure to cubic-TaN structure, subsequently leading to a decrease in hardness[14].Furthermore, the presence of Ta2N (100) in the hexagonal structure significantly influenced the hardness values, particularly in the R1 coating, where the highest hardness value of 28 GPa was achieved. This suggests that the microstructural arrangement of the coatings played a vital role in influencing their hardness property.…”