反应射频磁控溅射法制备HfTaO薄膜的热稳定性和光学性能

Thermal stability and optical properties of HfTaO films prepared by reactive RF magnetron sputtering

采用反应射频磁控溅射技术制备HfTaO薄膜,利用X射线衍射(XRD)分析了薄膜的微结构,通过紫外-可见光分光光度计测量了薄膜的透过谱,计算了薄膜的折射率和禁带宽度,利用原子力显微镜观察了薄膜的表面形貌。结果表明,随着Ta掺入量(10%,26%,50%)的增加,HfTaO薄膜的结晶化温度分别为800、900、950℃,Ta掺入量继续增加到72%,经过950℃退火处理的HfTaO薄膜仍然保持非晶态,具有优良的热稳定性。AFM形貌分析显示非晶HfTaO薄膜表面非常平整。在550nm处薄膜折射率n随着Ta掺入量的增大而增大,n的变化区间为1.90～2.15。同时HfTaO薄膜的光学带隙Eg随着Ta掺入量的增大而逐渐减小,Eg的变化区间为4.15～5.29eV。

Effects of Ta doping on microstructure, surface morphology, band gap and optical properties of HfO2 thin films deposited by reactive RF magnetron sputtering have been investigated by X-ray diffraction （XRD）, atomic force microscopy （AFM） and spectrophotometry. The results indicate that the introduction of Ta can improve the film crystallization temperature to 800,900 and 950℃ for HfTaO thin films containing 10 % Ta, 26 % Ta and 50%Ta,respectively. When the ratio of Ta/Hf＋Ta is about 72% ,the film remains amorphous at a high temperature up to 950℃. Thermal stability of the amorphous HfTaO film was significantly improved by the controlled addition of Ta. AFM results show that the amorphous HfTaO film is smooth. Refractive indice of the films increases from 1.90 to 2.15 with increasing Ta percentage. Eg was determined to be in the range 4.15-5.29 eV,the band gap energy of the HfTaO films as a function of increasing Ta percentage decreases.