三维电子束云纹法

3D SEM Scanning Moiré Method

三维电子束(3D电子束)云纹法是一种微尺度三维变形测量方法。该方法通过在试件表面制作高密度光栅,结合双目视觉立体成像技术,在SEM中形成两个角度的电子束云纹图,即可分析获得三维变形信息。考虑到离面变形与面内变形计算时的相互耦合关系,本文对现有的3D电子束云纹法进行了进一步发展,系统推导了3D电子束云纹法的通用理论公式。利用变形前后不同角度拍摄的电子束云纹图,可分别迭代计算出面内变形、离面变形和形貌等信息。对全息光栅鼓泡变形的验证实验证明了本文发展的3D电子束云纹法理论的正确性。

3D SEM Moire method is one of 3D micro-scale deformaiton meaurement methods. Through making high density grating on specimen surface, combining with binocular stereo vision imaging technology, electron beam Moire patterns from two different angles are formed in SEM. Thus, 3D deformaiton information can be obtained. Considering the coupling relation between in-plane and out- of-plane deformations in calculation, current 3D SEM Moire method was improved by authors, a general theoretical formula of 3D SEM Moire method was systematically deduced and present in this paper. In-plane, out-of-plane deformation and three-dimensional morphology information can be calculated separately by iteration based on SEM Moire patterns taken from two different angles before and after deformation. Bubbling deformation measurement of holographic grating verifies the feasibility of the 3D SEM Moire method.