界面粗糙度对真空紫外光学薄膜光谱性能影响研究

Research on the Effect of Interface Roughness on Spectral Properties of VUV Optical Thin Film

摘要:

设计了193nm窄角度和宽角度入射增透膜以及正入射高反膜,其中增透膜s和p偏振光透射率的最大偏差分别为0.17%和0.44%。结合标量散射理论和等效吸收层近似理论,多层膜间的粗糙界面等效为薄的吸收层,基于薄膜本征传输矩阵计算分析了不同界面粗糙度下的光谱性能。研究发现,薄膜光谱性能随着界面均方根粗糙度的增加而急剧退化,高反膜反射带宽也随之降低,达到4nm时,宽角度入射增透膜和高反膜光谱性能在193nm处分别退化2.04%和2.09%。界面粗糙度是影响高光谱性能真空紫外光学薄膜制备的重要因素。

Abstract:

Antireflection film with a narrow range of angle of incidence (AOI), antireflection film with a wide range of AOI, and multilayer high reflection thin film at 193nm were designed respectively. The maximum deviations of the s and p polarized light transmittances of the antireflection film were 0.17% and 0.44%, respectively. Combining the scalar scattering theory and the equivalent absorption layer approximation theory, the rough interface between the multilayer film was equivalent to a thin absorption layer, and the spectral properties at different interface roughness were analyzed based on the thin film intrinsic transfer matrix. The results show that the spectral performance of the optical thin film decrease with the increase of the root mean square roughness of the interface and the reflection bandwidth of the high reflection film also decrease. When the root mean square roughness reaches 4nm, the spectral performance of the antireflection film with a wide range of AOI and the multilayer high reflection film degrade by 2.04% and 2.09%, respectively. Interface roughness is the key factor affecting the preparation of VUV optical thin film with high spectral properties.