退火温度对HfO2薄膜应力和光学特性的影响

Effect of annealing temperature on stress and optical properties of hafnium dioxide Him

为了研究退火温度对HfO_2薄膜应力、光学常数和表面粗糙度的影响,采用电子枪蒸镀法制备了薄膜样品,在不同温度下进行了退火处理。利用ZYGO干涉仪、UV-3101PC分光光度计、X射线衍射仪和冷场发射扫描电镜对样品进行了测试。结果表明,在本实验条件下制备的HfO_2薄膜都是无定形结构;残余应力均为张应力,且随退火温度的升高呈先减小后增大现象,在300℃退火条件下具有最小应力;HfO_2薄膜折射率随退火温度的升高而增大,并且色散减小;低温退火可以提高HfO_2薄膜的平整度,高温退火反而会使HfO_2薄膜表面粗糙度增加。这些结果可以为制备高质量HfO_2薄膜提供参考。

In order to study the effect of annealing temperature on the stress, optical constants and surface roughness of HfO2 film, the film specimen was fabricated with electron beam evaporation method, then annealed at different temperatures. The film specimen was tested with i nterferometer, UV-3101 PC spectrophotometer, X-ray diffraction instrument and emission scanning electron microscopy. The experimental results show that the HfO2 film is amorphous under the experimental conditions. The residual stress is tensile stress, first decreases and then increases with annealing temperature, and achieve to the minimum at 300~C. The refractive index increases with annealing temperature, however the dispersion decreases with the annealing temperature. The film roughness annealing at low temperature is smaller than that at high temperature. These results can provide reference for the preparation of high-quality HfO2 films.