工件表面轮廓均方根斜率的光散射测量

Light-scattering measurement of the RMS slopes of rough surfaces

描述并确定具有明显纹理粗糙表面均方根斜率的光散射技术(均方根斜率是联合表面轮廓高度和波长特性的混合参数)。称为散射光锥法(The scattered light-conemethod)的该技术是基于激光角散射检测阵列(DALLAS——Defector Array for Laser LishtAngular Scattering),它用于测量粗糙表面散射光角分布的仪器。均方根斜率是从DALLAS光散射图象的角宽得到的。一般可以发现角宽(即估计的均方根斜率)对光的入射角和散射角变化相当大时是不敏感的。这些结果与表面材料无关,并且对正弦和随机粗糙表面都是有效的。介绍了散射光锥法的测量原理、实验、数据分析和几点结论。

This paper describes an optical scattering technique for deter- mining the RMS slope of a rough surface having a well-defined lay (the RMS slope is a hybrid parameter wihich combines both the amplitude and the wave- length properties of a surface profile). The technique, called the scattered light-cone method, is based on DALLAS (Detector Array for Laser Light Angu- lar Scattering), a research instrument which measures the angular distribution of light scattered from a rough sufrace. The RMS slope is obtained from the angular width of the DALLAS light-scattering pattern. In general it was found that the angular width, and thus the estimated RMS slope, is insensitive to relatively large changes in both the incidence and the scattering angles of the light. These results are independent of the surface material, and are valid for both sinusoidal and ran- dom rough surfaces. The measuring principles, experiments, data analysis, and conclusions involved in using the scattered light-cone method are described in this paper.