基于白光干涉法测量微光栅形貌及相关几何参量的研究

Measurement of the profile of a micro-grating and related parameters based on white light interferometry

基于显微白光干涉术,利用扫描干涉显微镜对四台阶面阵微光栅记录了128幅白光干涉图,并分别运用重心法、空间频域算法、移相算法及包络曲线拟合法对扫描干涉图进行了分析处理。被测微光栅的形貌及周期在各算法下均完全吻合,台阶总高最大相差0.8%。同时,用美国Veeco白光轮廓仪对同一样品的形貌及光栅周期进行了测试,数据显示两者结果非常吻合,仅台阶总高相差0.7%。研究结果表明,所采用的四种算法均适用于微观三维形貌的测量。

Based on microscopic white light interferometry,a self-developed scan interferometric microscope is used and 128 white-light interferograms are recorded for a four-step area array micro-grating. In the analysis,four different algorithms,including method of centre of gravity,spatial frequency domain algorithm,phase-shifting method, and envelope fitting algorithm,are adopted. Results based on the four methods agree well in terms of the profile and period of the grating, and total step height has a difference of 0. 8%. Meanwhile, a Veeco white-light profiler is used for measuring the sample, and data results also agree well with those obtained by the four algorithms for the profile and period with average total step height difference of 0. 7 % only. This indicates that the four algorithms used are all applicable to the measurement of micro-profiles.