C_2H_2/N_2气流下nc-ZrCN/a-CN_x薄膜成分、结构和力学性能的研究

Compositional,Structural and Mechanical Characteristics of nc-ZrCN/a-CN_x Films with Different Flows of C_2H_2/N_2 Gas

采用磁过滤阴极真空弧技术(FCVA),以金属Zr为阴极靶,通入不同流速的C_2H_2和N_2气体(两者比例保持为1∶1),在单晶Si(100)晶面上制备nc-ZrCN/a-CN_x纳米复合薄膜。采用扫描电镜(SEM)、X射线衍射(XRD)、透射电镜(TEM)、X射线电子能谱(XPS)和拉曼散射能谱(Raman)多种材料分析技术研究薄膜的成分和结构。实验结果表明:薄膜是由两种相结构组成,分别为ZrCN纳米晶相(nc-ZrCN)和非晶相(a-CN_x);结构是由平均晶粒尺寸为5~12nm的nc-ZrCN弥散于非晶相a-CN_x中。纳米晶相nc-ZrCN中键态为Zr-C和Zr-N,非晶相aCN_x中键态为C-C,C=C和C-N。利用表面形貌仪(SM)和纳米力学探针(Nanotest)测量了薄膜的内应力、硬度和约化模量等力学性能。分析发现:薄膜中sp3和sp2的含量比(sp3/sp2)越大,内应力越大,内应力最大可达11.5GPa。ZrCN纳米晶粒细化和高的sp3/sp2含量比会提高薄膜的硬度和约化模量。当气流在15~35ml·min^(-1)范围时,薄膜具有很高的硬度和约化模量。当气流为25ml·min^(-1)时,硬度可达35.1GPa,约化模量达297.2GPa。

Nanocomposite nc-ZrCN/a-CNx films were deposited on Si （100） substrates by filtered cathodic vacuum arc （FCVA） technique, using zirconium as cathodic and different flows of C2 H2/N2 gas as precursor. The effects of different flows of gas on compo- sitional and microstructural characteristics of nc-ZrCN/a-CNx films were investigated by scanning electron microscopy （ SEM ）, X-ray diffraction （XRD）, transmission electron microscope （TEM）, X-ray photoelectron spectroscopy （XPS） and Raman scattering spec- troscopy. The results showed that nc-ZrCN/a-CNx films were composed of 5 - 12 nm ZrCN nanoclTstalline phase embeded in a-CNx a- morphous phase. The chemical bondings of ZrCN nanocrystalline and a-CNx amorphous phase consisted of Zr - C, Zr - N and C - C, C = C as well as C - N, respectively. The internal stress, hardness and reduced modulus were measured by surface morphology and mi- croindentation. It was found that the higher the spa/sp2 ratio was, the larger the internal stress became, and the maximum internal stress was up to 11.5 GPa. Nanocrystalline refinement and high sp3/sp2 ratio improved the hardness and reduced the modulus of films. The ne-ZrCN/a-CNx films possessed a high hardness and a reduced modulus at 15 - 35 ml.min-1 , and the maximum hardness and re- duced modulus reached 35.1 and 297.2 GPa at 25 ml min-1 , respectively.