论文部分内容阅读
白光干涉技术具有高度唯一性,广泛地被使用在三维表面形貌和台阶高度的测量。但是测量透明薄膜时,薄膜表面和基面都有光线反射与参考光线交汇,在被测表面的同一个位置不同高度两次产生干涉条纹,其干涉相干图中出现两个峰值。通过分析透明薄膜产生的干涉相干图的特点,提出了两种算法用来分离不同表面产生的干涉条纹。理论分析和试验结果表明,利用垂直扫描白光干涉法测量透明薄膜,由峰值分离算法和定位算法分别提取薄膜的上下表面,能够得到透明薄膜的高精度三维形貌和厚度信息。
White light interference technology is highly unique and is widely used in the measurement of three-dimensional surface topography and step height. However, when the transparent film is measured, both the film surface and the base surface have light reflection and reference light intersection, and interference fringes occur at two different heights at the same position of the measured surface, and two peaks appear in the interference coherence diagram. Two kinds of algorithms are proposed to separate the interference fringes produced on different surfaces by analyzing the characteristics of the interference coherent graph produced by the transparent film. The theoretical analysis and experimental results show that the transparent thin films can be measured by the vertical scanning white light interferometry, and the top and bottom surfaces of the thin films can be extracted by the peak separation algorithm and the localization algorithm respectively to get the high-precision three-dimensional topography and thickness information of the transparent thin films.