A Traceable Metrological Method with Nanometer Scale Resolution for Micro-Structure

Micro-structure dimension metrology is a grand challenge to current metrological methods and tools. In this paper, a retraceable metrological scanning electron microscopy (M-SEM) system with precision stage and laser interferometer is presented in detail. The double stages structure is used to realize both sample positioning in 50mm×50mm range and accuracy imaging in several tens of micron scale. In order to acquiring metrological scanning image, the control system based on digital signal processing (DSP) is constructed. Furthermore, this paper focuses on demonstrating a metrological SEM image edge detection algorithm which is the essential part of the metrological SEM system to realize the traceable metrology of line width.