热处理对SiO_2薄膜折射率和吸收特性的影响分析

Analysis on effects of thermal treatment on refractive index and absorption properties of SiO_2 film

采用离子束溅射技术,在熔融石英基底上制备了SiO2薄膜,并通过椭偏光谱法和表面热透镜技术研究了热处理对其光学特性的影响。热处理对离子束溅射SiO2薄膜折射率影响较大,随着热处理温度增加,SiO2薄膜折射率先减小后增大,当热处理温度为550℃时,折射率达到最小。经过热处理后,SiO2薄膜的弱吸收均得到了降低,在2ppm(1ppm=10-6)左右,当热处理温度为550℃时,获得的SiO2薄膜弱吸收最小仅为1.1ppm。实验结果表明:采用合适的热处理温度,能大大改善离子束溅射SiO2薄膜的折射率和吸收特性。

SiO2 films were deposited on fused silica sub strates by ion beam sputtering technology and the effects of thermal treatment on optical properties were studied by ellipsometry technology and surface thermal lens technology. The effects of thermal treatment temperature on refractive index of IBS-SiO2 films were very large, as the increase of thermal treatment temperature, refractive index of SiO2 films first decrease and then increased, when the thermal treatment temperature was 550℃, the refractive index was the minimum. After thermal treatment, the weak absorption of SiO2 films were all reduced, the value of weak absorption was about 2 ppm. When the thermal treatment temperature was 550℃, the least weak absorption of 1.1 ppm was obtained. The results show that refractive index and absorption properties of IBS-SiO2 films can be largest improved by the proper thermal treatment temperature.