偏压对离子源辅助HiPIMS制备纳米TiN薄膜力学性能和耐蚀性能的影响

为提高磁控溅射制备薄膜的致密度,减少结构缺陷,研究薄膜显微结构对硬度、韧性及耐蚀性能的影响,尝试在改变离子源和基材偏压的条件下,采用离子源辅助HiPMIS技术在304不锈钢和P型（100）晶向硅片上制备TiN纳米薄膜。采用扫描电子显微镜、小角X射线衍射仪对薄膜的形貌和晶体结构进行分析;采用纳米压痕仪和维氏硬度计分别测量计算薄膜的硬度和韧性,并通过电化学工作站对薄膜的耐蚀性能进行检测。结果表明：随着偏压的增加以及离子源的引入,离子的轰击效应增强,薄膜的沉积速率下降,致密度增加。偏压为-200 V时,薄膜的硬度达到最大值16.2 GPa,且对应的晶粒尺寸最小,（111）晶面衍射峰的强度最高。离子源的加入使所制备薄膜的硬度略有下降。此外,随着偏压的增加,薄膜的韧性和耐腐蚀性能也有一定提高。     

Wear behavior of HPPMS deposited (Ti,Al,Si)N coating under impact loading

Over the last decade the interest in High Power Pulse Magnetron Sputtering (HPPMS) and High impulse Magnetron Sputtering (HiPIMS) has undergone a considerable increase. This is mainly due to the fact that several researchers have shown that in these processes a distinct increase of the ionization of deposition species is observable. However, there is only little known about the performance of these films with regard to applications. Recently Hovsepian et al. [1] and Bobzin et al. [2] presented cutting results of different films. Both authors show that films deposited using HPPMS or HiPIMS outperform state‐of‐the‐art coatings. Depending on the cutting process, besides hardness and adhesion also excellent impact behavior is required. Therefore this work deals with the impact behavior of (Ti,Al,Si)N which was deposited using HPPMS for the application in interrupted cutting process. The impact behavior of HPPMS coating under normal and tangential loads is analyzed. During impact tests number of impacts, loads and inclination angle of the samples with regard to the load direction are varied. (Ti,Al,Si)N shows an excellent endurance even at very high loads causing Hertzian stresses in the range of 10–13 GPa. At an inclination angle of 10° and an impact load of 100 N, which corresponds to app. 10 GPa initial Hertzian stress, no damage was observed after 800×10³ impacts.     

Magnetron sputtering - Milestones of 30 years

Since the introduction of the planar magnetron by J.S. Chapin in 1974 magnetron sputtering has become the most important technology for the deposition of thin films. Today it has conquered all industrial branches needing high-quality coatings for realization of new or improvement of existing products. The magnetron cathode combines the advantages of economic deposition even on large areas and the ability to coat very temperature sensitive plastic substrates. Main problems like poor target material utilization of the planar magnetron or process instabilities during deposition of highly insulating films have been solved by many innovations during the past 30 years. Novel films with even better quality seem to be possible with “High Power Impulse Magnetron Sputtering (HiPIMS)”. New attempts to increase sputter yield and thus film growth rate are “Sputter Yield Amplification (SYA)” or sputtering from hot targets. This paper gives a brief review on important milestones of the past three decades and outlines some ongoing developments.     

Effect of peak power in reactive high power impulse magnetron sputtering of titanium dioxide

The effect of peak power in a high power impulse magnetron sputtering (HiPIMS) reactive deposition of TiO₂ films has been studied with respect to the deposition rate and coating properties. With increasing peak power not only the ionization of the sputtered material increases but also their energy. In order to correlate the variation in the ion energy distributions with the film properties, the phase composition, density and optical properties of the films grown with different HiPIMS-parameters have been investigated and compared to a film grown using direct current magnetron sputtering (DCMS). All experiments were performed for constant average power and pulse on time (100 W and 35 μs, respectively), different peak powers were achieved by varying the frequency of pulsing. Ion energy distributions for Ti and O and its dependence on the process conditions have been studied. It was found that films with the highest density and highest refractive index were grown under moderate HiPIMS conditions (moderate peak powers) resulting in only a small loss in mass-deposition rate compared to DCMS. It was further found that TiO₂ films with anatase and rutile phases can be grown at room temperature without substrate heating and without post-deposition annealing.     

高功率脉冲磁控溅射制备ZnO薄膜的研究进展

氧化锌薄膜材料由于具有高电导率、良好的光学透过率、原料储存丰富、成本低廉的特点,被认为是最具有潜力的透明导电薄膜。特别是其宽禁带(3.37e V)和高达60meV的激子束缚能,使其在环境温度制备同质结发光器件、太阳能电池电子传输层具有巨大的应用前景。然而,传统制备方法难以实现薄膜质量的综合调控,存在p-ZnO稳定性差、制备的薄膜重复性差、组装的器件效能较低等问题。高功率脉冲磁控溅射(HiPIMS)技术具有溅射材料离化率高的特点,非常适合需要离子反应的各类薄膜。当采用HiPIMS制备氧化物、碳化物、氮化物薄膜时,利用其高电离率还可以获得较高的靶离子和掺杂离子,可实现晶格替代、间隙原子等缺陷的形成,制备稳态的材料,如制备稳定p-型半导体材料。本文综述了近年来HiPIMS制备氧化锌薄膜的研究进展,主要是给出HiPIMS制备ZnO薄膜的放电特性和工艺参数的影响,最后展望了HiPIMS制备稳定p-ZnO薄膜的发展方向。     

Microstructure and properties of TiAlCrN ceramic coatings deposited by hybrid HiPIMS/DC magnetron co-sputtering

TiAlCrN ceramic coatings were prepared utilizing a hybrid deposition technique consisting of High Power Impulse Magnetron Sputtering (HiPIMS) and Direct Current Magnetron Sputtering (DCMS). The chemical composition, phase structure, morphologies, mechanical and tribological properties of such coatings were systematically investigated. Results indicated that the content of Ti element increased monotonically from 0 at.% to 22 at.% with increasing of Ti target power. The TiAlCrN ceramic coatings presented a competitive growth tendency between (111) and (200) crystal plane through the energetic ion bombardment. Higher Ti target power resulted in stronger compressive intrinsic stress, which significantly suppressed the precipitation of hcp-AlN phase. With enhancing ion bombardment, diffusion energy and nucleation rate of adatoms on the growing surface increased, which caused a denser structure and ultra-smooth surface. The hardness and toughness also varied as a function of Ti target power, with the maximum hardness of 28.3 GPa under a Ti target power of 5 kW. Positive correlation between the adhesion strength (i.e., the critical load of the scratch test) and H³/E² ratio was discovered indicating a strong dependence of adhesion properties on toughness for the TiAlCrN ceramic coatings in this study, which agreed well with the literatures. As for the tribological behavior, the lowest wear rate of 8.9 × 10^-17 m³N^-1m^-1 was obtained for the TiAlCrN ceramic coating deposited at a Ti target power of 5 kW.     

Contribution of enhanced ionization to the optoelectronic properties of p-type NiO films deposited by high power impulse magnetron sputtering

Herein, intrinsic p-type conductivity of NiO films were enhanced by high power impulse magnetron sputtering (HiPIMS) technology, where more charged Ni³⁺ ions are created during the deposition process. The formation of Ni³⁺ ions are advantageous for strengthening the p-type conductivity of NiO films. As the pulse off-time increases from 0 μs to 3000 μs, Ni³⁺ concentration improves greatly, indicating the amount of Ni vacancies as well as the hole concentration significantly enhances. It confirms that HiPIMS is a preferential technology for preparing NiO films with high p-type conductivity. Especially, when pulse off-time reaches 3000 μs, a high carrier concentration of 2.86 × 10²¹ cm⁻³ and a relatively low electrical resistivity about 0.07 Ω·cm are achieved.     

Fully dense, non-faceted 111-textured high power impulse magnetron sputtering TiN films grown in the absence of substrate heating and bias

We demonstrate the deposition of fully dense, stoichiometric TiN films on amorphous SiO₂ by reactive high power impulse magnetron sputtering (HiPIMS) in the absence of both substrate heating and applied bias. Contrary to the highly underdense layers obtained by reactive dc magnetron sputtering (dcMS) under similar conditions, the film nanostructure exhibits neither intra- nor intergrain porosity, exhibiting a strong 111 preferred orientation with flat surfaces. Competitive grain growth occurs only during the early stages of deposition (< 100 nm). The strong differences in the kinetically-limited nanostructural evolution for HiPIMS vs. dcMS are explained by high real-time deposition rates with long relaxation times, high ionization probabilities for Ti, and broad ion energy distributions.     

Structure and mechanical properties of TiAlN-WNx thin films

A combinatorial method was employed to grow TiAlN-WNx films by DC sputtering as well as by High Power Pulsed Magnetron Sputtering (HPPMS) where the W concentration was varied between 10-52 at.% and 7-54 at.%, respectively. Experiments were paired with ab initio calculations to investigate the correlation between composition, structure, and mechanical properties. During all depositions the time averaged power was kept constant. As the W concentration was increased, the lattice parameter of cubic TiAlN-WNx films first increased and then decreased for W concentrations above ≈ 29 at.% (DCMS) and ≈ 27 at.% (HPPMS) as the N concentration decreased. Calculations helped to attribute the increase to the substitution of Ti and Al by W and the decrease to the presence of N vacancies. Young's modulus and hardness were around 385-400 GPa and 29-31 GPa for DCMS and 430-480 GPa and 34-38 GPa for HPPMS, respectively, showing no significant trend as the W concentration was increased, whereas calculations showed a continuous decrease in Young's modulus from 440 to 325 GPa as the W concentration was increased from 0 to 37.5 at.%. The presence of N vacancies was shown to increase the calculated Young's modulus. Hence, the relatively constant values measured may be understood based on N vacancy formation as the W concentration was increased. HPPMS-deposited films exceed DCMS films in Young's modulus and hardness, which may be a consequence of the larger degree of ionization in the HPPMS plasma. It is reasonable to assume that especially the ionized film forming species may contribute towards film densification and N vacancy formation.