The rapid development of micro-electronics and micro-nano material engineering make it an urgent task to characterize the mechanical properties of micro-device and micro-nano material accurately. Due to the advantages of high precision, high sensitivity and full field measurement, moiré method has been applied in the micro-deformation measurement widely. Since the grating is the indispensable deformation sensor of moiré method, how to fabricate high frequency grating with high quality is the key problem to solve for moiré method. In this paper, some fabrication techniques developed recently with their applications will be summarized, including holographic photolithography, electron beam lithography (EBL), focused ion beam (FIB) and nano-imprint lithography(NIL), aiming to popularize the applications of moiré method in the micro-deformation measurement and provide some valuable guidelines on how to choose a proper fabrication technique.
Microscopes are widely applied in characterizing feature sizes at the micro-/nanoscale, and magnification calibration plays a key role in achieving precise measurements. However, it is difficult to obtain accurate results by using the general magnification calibration method if comparing the displayed size of a test-piece under microscope and its original one. In this study, a high-accuracy and automatic magnification calibration method that could be applied to different types of microscopes is proposed. A standard grating is employed as the reference, and a high-resolution discrete Fourier transform is used to analyze the images captured under various magnifications in this method. With utilization of the high-order harmonic component in the Fourier spectrum, the proposed method is capable of performing the calibration over a wide range of magnifications while maintaining identical precision. The relative error of the proposed method can be theoretically limited to 0.01%; moreover, the image noise can be tolerated. Furthermore, the validation and extensive adaptability of this method are demonstrated by calibrating the magnification of a scanning electron microscope and an optical microscope.