SEM扫描云纹法的相移技术研究

提出一种扫描电镜(SEM)扫描云纹法的相移新技术,通过SEM系统控制电镜电子束扫描线移动,对获取的云纹图像实现0-2π范围内的四步相移,从而获得了更高的位移测量灵敏度。同时对SEM扫描云纹法的测量原理以及相移实验技术的原理进行了详细的阐述。并将该技术应用到电子封装试件栅的相移分析中。实验结果证明了该方法的可行性,该方法为微米云纹法的条纹处理提供了一种新途径。

Phase shifting techniques for SEM scanning moire method

A new phase shifting technique for scanning electron microscope(SEM) scanning moire method is proposed. The phase shifting was realized in four steps from 0 to 2π by shifting electron beam controlled by the SEM. In this method, holographic grating is replicated to the testing area of the specimens to generate SEM scanning moiré. A scanning electron beam, which carries equally spaced grid, is exposed on the specimen. The electron beam on the specimen with the model grid produces moiré fringes of bright and dark lines on the monitor of SEM .The phase shifting technique used in electron moiré method provides a new way for disposal of fringes pattern in sub micro moiré method. The principle of electron moiré method and phase shifting technique related to electron moiré method are explained, and the method is applied to determine the phase distribution in SEM moiré formed by a deformed grating with frequency of 1200 lines/mm in an electronic package. The experiment proves the validity of this technique, and shows the sensitivity of experiments is highly improved after phase shifting technique contrasting to common electron beam moiré method.