测量薄膜微粗糙度的总积分散射仪

介绍了一种检测光学薄膜表面总积分散射（TIS）分布的总积分散射仪。对仪器的基本结构、理论基础、测量原理以及系统性能等进行了阐述，提出了抑制系统噪音和提高测量精度的有效措施。利用该仪器对K9基底上的银（Ag）膜和氧化锆（ZrO2）薄膜进行了测量，并根据标量散射理论得到了表面均方根（RMS）粗糙度。利用光学轮廓仪和原子力显微镜（AFM）分别测量了上述Ag膜和ZrO2薄膜的表面均方根粗糙度，并与总积分散射仪所得的粗糙度进行了比较。结果表明，根据测量的薄膜表面总积分散射计算得到的表面均方根粗糙度与光学轮廓仪及原子力显微镜测量得到的表面均方根粗糙度符合得较好，相差在0．01～0．13nm范围内。

Total Integrated Scatterometer for Measuring the Microroughness of Optical Thin Films

In this paper, an instrument for detecting the distribution of the surface total integrated scattering (TIS) of the optical thin films is introduced. The apparatus structure, theoretic foundation, measuring principle, and the system performance of the instrument are described. Effective means are adopted to control the noise and to improve the measuring accuracy of the system. Silver (Ag) layers and zirconia (ZrO2) films deposited on K9 glasses are measured by this instrument, then using the scalar scattering method, the root mean square (RMS) roughness of these films are calculated. Optical profilometer and atomic force microscopy (AFM) are used to obtain the surface RMS roughness of Ag layers and ZrO2 films, respectively, which are compared with the roughness obtained by the scattering instrument. It is shown that the surface RMS roughness of the optical films calculated in terms of the TIS measurements agrees well with that obtained by optical profilometer and AFM measurement, and the difference is within 0.01～0.13 nm.