Fischer Maria, Trant Mathis, Thorwarth Kerstin, Crockett Rowena, Patscheider Jörg, Hug Hans Josef
Laboratory for Nanoscale Materials Science, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
Solution Design, Evatec AG, Trübbach, Switzerland.
Sci Technol Adv Mater. 2019 Sep 25;20(1):1031-1042. doi: 10.1080/14686996.2019.1666425. eCollection 2019.
Optically transparent, colorless Al-O-N and Al-Si-O-N coatings with discretely varied O and Si contents were fabricated by reactive direct current magnetron sputtering (R-DCMS) from elemental Al and Si targets and O and N reactive gases. The Si/Al content was adjusted through the electrical power on the Si and Al targets, while the O/N content was controlled through the O flow piped to the substrate in addition to the N flow at the targets. The structure and morphology of the coatings were studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM), while the elemental composition was obtained from Rutherford backscattering spectrometry (RBS) and heavy ion elastic recoil detection analysis (ERDA). The chemical states of the elements in the coatings were analyzed by X-ray photoelectron spectroscopy (XPS). Based on analytical results, a model describing the microstructural evolution of the Al-O-N and also previously studied Al-Si-N [1, 2, 3, 4] coatings with O and Si content, respectively, is established. The universality of the microstructural evolution of these coatings with the concentration of the added element is attributed to the extra valence electron (e) that must be incorporated into the AlN wurtzite host lattice. In the case of Al-O-N, this additional valence charge arises from the e acceptor O replacing N in the AlN wurtzite lattice, while the e donor Si substituting Al fulfills that role in the Al-Si-N system. In view of future applications of ternary Al-O-N and quaternary Al-Si-O-N transparent protective coatings, their mechanical properties such as residual stress (), hardness (HD) and Young's modulus (E) were obtained from the curvature of films deposited onto thin substrates and by nanoindentation, respectively. Moderate compressive stress levels between -0.2 and -0.5 GPa, which suppress crack formation and film-substrate delamination, could be obtained together with HD values around 25 GPa.
通过反应直流磁控溅射（R-DCMS），以元素铝靶和硅靶以及氧和氮反应气体为原料，制备了具有离散变化的氧和硅含量的光学透明、无色的Al-O-N和Al-Si-O-N涂层。通过调节硅靶和铝靶上的电功率来调整Si/Al含量，同时除了靶材处的氮气流外，还通过输送到基板的氧气流来控制O/N含量。通过X射线衍射（XRD）和透射电子显微镜（TEM）研究涂层的结构和形态，而通过卢瑟福背散射光谱（RBS）和重离子弹性反冲探测分析（ERDA）获得元素组成。通过X射线光电子能谱（XPS）分析涂层中元素的化学状态。基于分析结果，分别建立了描述Al-O-N以及先前研究的具有氧和硅含量的Al-Si-N[1,2,3,4]涂层微观结构演变的模型。这些涂层微观结构演变随添加元素浓度的普遍性归因于必须纳入AlN纤锌矿主晶格的额外价电子（e）。在Al-O-N的情况下，这种额外的价电荷源于在AlN纤锌矿晶格中取代N的电子受体O，而在Al-Si-N系统中，电子供体Si取代Al起到了该作用。鉴于三元Al-O-N和四元Al-Si-O-N透明保护涂层的未来应用，分别通过沉积在薄基板上的薄膜曲率和纳米压痕获得了它们的机械性能，如残余应力（）、硬度（HD）和杨氏模量（E）。可以获得-0.2至-0.5 GPa之间的适度压缩应力水平，这抑制了裂纹形成和膜-基板分层，同时HD值约为25 GPa。
