Thin Film Physics Division, Department of Physics (IFM), Linköping University , SE-581 83 Linköping, Sweden.
IHI Ionbond AG , Industriestraße 211, CH-4600 Olten, Switzerland.
ACS Appl Mater Interfaces. 2016 Aug 10;8(31):20385-95. doi: 10.1021/acsami.6b05830. Epub 2016 Jul 26.
Reactive high power impulse magnetron sputtering (rHiPIMS) was used to deposit silicon nitride (SiNx) coatings for biomedical applications. The SiNx growth and plasma characterization were conducted in an industrial coater, using Si targets and N2 as reactive gas. The effects of different N2-to-Ar flow ratios between 0 and 0.3, pulse frequencies, target power settings, and substrate temperatures on the discharge and the N content of SiNx coatings were investigated. Plasma ion mass spectrometry shows high amounts of ionized isotopes during the initial part of the pulse for discharges with low N2-to-Ar flow ratios of <0.16, while signals from ionized molecules rise with the N2-to-Ar flow ratio at the pulse end and during pulse-off times. Langmuir probe measurements show electron temperatures of 2-3 eV for nonreactive discharges and 5.0-6.6 eV for discharges in transition mode. The SiNx coatings were characterized with respect to their composition, chemical bond structure, density, and mechanical properties by X-ray photoelectron spectroscopy, X-ray reflectivity, X-ray diffraction, and nanoindentation, respectively. The SiNx deposition processes and coating properties are mainly influenced by the N2-to-Ar flow ratio and thus by the N content in the SiNx films and to a lower extent by the HiPIMS frequencies and power settings as well as substrate temperatures. Increasing N2-to-Ar flow ratios lead to decreasing growth rates, while the N content, coating densities, residual stresses, and the hardness increase. These experimental findings were corroborated by density functional theory calculations of precursor species present during rHiPIMS.
反应性高功率脉冲磁控溅射(rHiPIMS) 用于沉积氮化硅(SiNx) 涂层，用于生物医学应用。在工业镀膜机中使用 Si 靶和 N2 作为反应气体进行 SiNx 生长和等离子体特性研究。研究了不同 N2 与 Ar 流量比(0 至 0.3)、脉冲频率、靶功率设置和衬底温度对放电和 SiNx 涂层 N 含量的影响。等离子体离子质谱显示，在低 N2 与 Ar 流量比(<0.16)的放电初始部分，有大量的离子化同位素，而在脉冲结束和脉冲关闭期间，离子化分子的信号随着 N2 与 Ar 流量比的升高而增加。Langmuir 探针测量显示，非反应性放电的电子温度为 2-3 eV，过渡模式放电的电子温度为 5.0-6.6 eV。通过 X 射线光电子能谱、X 射线反射率、X 射线衍射和纳米压痕分别对 SiNx 涂层的组成、化学键结构、密度和机械性能进行了表征。SiNx 沉积过程和涂层性能主要受 N2 与 Ar 流量比的影响，进而受 SiNx 薄膜中的 N 含量的影响，受 HiPIMS 频率和功率设置以及衬底温度的影响较小。增加 N2 与 Ar 流量比会导致生长速率降低，而 N 含量、涂层密度、残余应力和硬度增加。这些实验结果得到了反应性高功率脉冲磁控溅射中存在的前体物质的密度泛函理论计算的证实。
