Araiza José de Jesús, Álvarez-Fraga Leo, Gago Raúl, Sánchez Olga
Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, Cantoblanco, 28049 Madrid, Spain.
Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad Esq, Paseo La Bufa, Fracc, Progreso, Zacatecas 98060, Mexico.
Materials (Basel). 2023 Jul 29;16(15):5331. doi: 10.3390/ma16155331.
Hafnium oxide films were deposited on sapphire and silicon (100) substrates using the DC reactive magnetron sputtering technique from a pure hafnium target at different discharge power levels. The influence of the cathode power on the chemical composition, morphology, crystallographic structure and optical properties of the films was investigated. X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and Fourier-transform infrared spectroscopy (FTIR) were employed to determine the chemical composition and bonding structure. In all cases, the films were found to be amorphous or nanocrystalline with increased crystalline content as the sputtering power was increased, according to XRD and FTIR. In addition, EDX showed that the films were oxygen-rich. The effect of power deposition on the surface topography and morphology of the films was studied using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The AFM and SEM images revealed the emergence of mound morphologies as the cathode power was increased. These features are related to blistering effects probably due to the presence of stress and its promotion within the film thickness. Finally, the optical properties showed an average transmission of 80% in the visible range, and the refractive index determined by spectral ellipsometry (SE) was found to be in the range of 1.85-1.92, close to the reported bulk value. SE was also used to study the film porosity observed by SEM, which can be related to the oxygen-rich character of the films.
采用直流反应磁控溅射技术，以纯铪靶材在不同放电功率水平下，在蓝宝石和硅（100）衬底上沉积氧化铪薄膜。研究了阴极功率对薄膜化学成分、形貌、晶体结构和光学性能的影响。采用X射线衍射（XRD）、能量色散X射线分析（EDX）和傅里叶变换红外光谱（FTIR）来确定化学成分和键合结构。根据XRD和FTIR分析，在所有情况下，薄膜均为非晶态或纳米晶态，且随着溅射功率的增加，结晶含量增加。此外，EDX表明薄膜富含氧。使用原子力显微镜（AFM）和扫描电子显微镜（SEM）研究了功率沉积对薄膜表面形貌的影响。AFM和SEM图像显示，随着阴极功率的增加，出现了丘状形貌。这些特征可能与由于薄膜厚度内应力的存在及其促进作用而产生的起泡效应有关。最后，光学性能表明在可见光范围内平均透过率为80%，通过光谱椭偏仪（SE）测定的折射率在1.85 - 1.92范围内，接近报道的体材料值。SE还用于研究SEM观察到的薄膜孔隙率，这可能与薄膜的富氧特性有关。
