SiO2薄膜是光学薄膜领域内常用的重要低折射率材料之一。文中采用不同沉积技术在Si基底上制备了SiO2薄膜, 并研究了它们光学特性的自然时效特性。采用不同贮存时间的椭偏光谱表征SiO2薄膜的光学特性, 随着时间的增加, EB-SiO2薄膜和IAD-SiO2薄膜的物理厚度和光学厚度随着增加, 但IBS-SiO2薄膜随着减小, 变化率分别为1.0%, 2.3%和-0.2%。当贮存时间达到120天时, IBS-SiO2薄膜、EB-SiO2薄膜和IAD-SiO2薄膜的物理厚度和光学厚度趋于稳定。实验结果表明, IBS-SiO2薄膜的光学特性稳定性最好, 在最外层保护薄膜选择中, 应尽可能选择离子束溅射技术沉积SiO2薄膜。

SiO2 thin films is one of the most important low refractive index materials in the field of optical thin film. SiO2 thin films were deposited on Si substrates by different deposition technique. The optical stability of SiO2 thin films were investigated as a function of time placed in the air. Optical constants of SiO2 thin films were calculated using the ellipsometry spectra at different aging times. With the increase of the placed time, the physical thickness and optical thickness of EB-SiO2 thin films and IAD-SiO2 thin films increase, but IBS-SiO2 thin film decreases. The change of optical thickness of SiO2 thin films are separately 1.0%, 2.3% and -0.2%. When the placed time reaches 120 days, the physical thickness and optical thickness of IBS-SiO2 thin films, EB-SiO2 thin films, and IAD-SiO2 thin films tend to be stable. The results indicate that the optical stability of IBS-SiO2 thin film is better than other SiO2 thin films, and in the design of protective coating, SiO2 thin films should be deposited with ion beam sputtering technique.