薄膜非均匀性的无损检测对于制备大面积高质量的红外透明薄膜尤为重要。针对红外薄膜光学均匀性难以获取的困难, 提出了一种同时获得单层透明红外薄膜厚度和折射率均匀性的无损检测方法。实验上, 通过磁控溅射法在二氧化硅衬底上制备了厚度约1.4 μm红外透明Ge-Sb-Se硫系薄膜, 然后在该薄膜上标定出36个80 μm×80 μm区域, 利用显微傅里叶红外光谱仪测得该36个区域的透射谱, 通过分段滤波的方法滤除背景噪声, 运用改进的Swanepoel方法计算得到了薄膜每一个区域的厚度和折射率, 进而精确获得该薄膜的厚度和折射率均匀性, 结果表明精度优于0.5%。

The non-destructive testing of the non-uniformity of films is important in the preparation of large-area, high-quality infrared transparent films. In this study, a method is proposed to obtain the thickness and refractive index non-uniformity of the film. In the experiments, an infrared Ge-Sb-Se chalcogenide film was prepared on a silicon dioxide substrate using magnetron sputtering. The transmission spectra of 36 areas with a size of 80 μm×80 μm were measured using a microscopic Fourier infrared spectrometer. Further, the background noise was filtered out with the segmentation filtering method. Finally, the thickness and refractive index of each area were calculated using the improved Swanepoel method, and the non-uniformity of the film was accurately obtained by comparing the test results from different areas. The results indicate that the calculation accuracy of the film non-uniformity is better than 0.5%.