锗(Ge)薄膜是中长波红外区最常用的光学薄膜之一, 高的聚集密度对于提升光谱稳定性和光学薄膜元件的品质非常重要。选用纯度为 99.99%的 Ge材料, 在 5×10-4 Pa左右的真空压力下用电子束蒸发沉积, 石英晶振仪将沉积速率控制在 0.8~1.0 nm/s范围, 宝石片基片上的膜层厚度约为 0.8~1.0 μm, 在不同沉积温度下制备样品。用傅里叶红外光谱仪测量吸潮前后薄膜的光谱曲线, 根据波长漂移理论, 计算出薄膜的聚集密度。结果表明: 聚集密度随沉积温度的升高而增加, 从常温沉积的约 0.74上升到 250℃沉积的0.99以上。

Germanium(Ge) thin films is one of the most commonly used optical film in long-wave and medium-wave infrared. High packing density for enhancing the spectra stability and the quality of the optical thin film elements is extremely important. Using 99.99% purity of the Ge materials, Ge thin films were prepared by electron beam evaporation in about 5×10-4 Pa vacuum pressure at different deposited temperature, while deposition rate was monitored and demonstrated at 0.8 ~ 1.0 nm/s by quartz crystal oscillation controller. The thickness of the thin films on silicon substrate is about 0.8 ~ 1.0 μm. Using the Fourier transform infrared spectrometer to test the spectral characteristics of Ge thin films before and after the thin film suck tide, according to the wavelength deviation dispersion theory, the packing density is calculated. The results show that as the deposition temperature increases, the packing density increases from 0.74 at room temperature to 0.99 at 250℃.