The effect of DC negative bias (− Vs) on microstructure and surface morphology of amorphous silicon carbide thin films prepared by helicon wave plasma chemical vapor deposition is reported. Microstructure and surface morphology were obtained by scanning electron microscope (SEM) and atomic force microscope (AFM). The results show that the increase of − Vs on the substrate make a more compact film and lower surface roughness, which can reach 0.56 nm. The XRD analysis reveals that the SiC thin films are of an amorphous structure. Percentages of carbon and silicon atoms (C/Si) were measured by energy dispersive spectrometer (EDS), and the C/Si ratio can reach 1.45. The structural properties of the films were studied by Raman spectroscopy techniques and Fourier transform infrared (FTIR). It is found that the films contain not only Si–C bonds but also Si–CHx bonds. Raman spectra results show that the proportion of disordered carbon in the films decreases with the increase of − Vs. The results of ultra-microhardness tester show that the hardness of the films increases with the increase of − Vs and the maximum mechanical hardness can reach 18.5 GPa at − Vs = − 60 V.

中文翻译：

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DC负偏压对HWP-CVD制备非晶碳化硅薄膜微观结构和表面形貌的影响

报道了直流负偏压（-Vs）对螺旋波等离子体化学气相沉积制备的非晶碳化硅薄膜的微观结构和表面形貌的影响。通过扫描电子显微镜（SEM）和原子力显微镜（AFM）获得显微结构和表面形貌。结果表明，衬底上-Vs的增加使薄膜更致密，表面粗糙度降低，可达0.56 nm。XRD 分析表明 SiC 薄膜具有非晶结构。通过能谱仪（EDS）测量碳和硅原子的百分比（C/Si），C/Si比可以达到1.45。通过拉曼光谱技术和傅里叶变换红外（FTIR）研究了薄膜的结构特性。发现薄膜不仅包含 Si-C 键，还包含 Si-CHx 键。拉曼光谱结果表明薄膜中无序碳的比例随着-Vs 的增加而减少。超显微硬度计结果表明，薄膜的硬度随着-Vs的增加而增加，最大机械硬度在-Vs=-60V时可达18.5GPa。