The Study Of Vibration Analysis Of Nano Micro-Displacement Platform In Metrological Scanning Electron Microscope

Scanning electron microscope(SEM) is an effective tool to characterize the morphology and microstructure. It has been generally used in lots of high-tech researches.Though the SEM has a high resolution of nanometer, it cannot precisely measure the size of the sample, because the imaging method of scanning the electron beam has no traceability. Therefore, we need a SEM with the metrological function of traceability.One of the best ways is to fix the electron beam and move the sample stage with scanning motion instead of the electron beam. Use the laser interferometer to measure the moving stage, and achieve a metrological precision image. Because of the nano-moving of the sample stage makes the coupling vibration, it is required high quality with the braced structure. Therefore, braced structure is of great significance to modify and reconstruct the metrological SEM.The main research work and results are about the support structure in the metrological scanning electron microscope. The components are as followed:We use the microsoft ANSYS to do finite element analysis about the modified support structure and flexure hinge stage in the metrological scanning SEM. We obtain the natural frequency and modified the formation to meet the requirement of the metrological SEM, and analyze the structure that match the metrological SEMThe vibration test about the modified nano-movement stage has been carried out.The resonance frequency is obtained by introducing variable frequency sine wave signal.The resonance frequency of the support structure is obtained by knocking the modified sample stage. The vibration signal in time domain received by a laser vibrometer is transferred to the signal in frequency domain by using fast Fourier transmission.The modification in this research is based on the Merlin SEM(ZEISS). A Coaxial Lidar measuring module and the metrological SEM system are added to the SEM to fulfill the metrological function of traceability in SEM,and use the scan imaging effect to verification the performance of vibration isolation and resist disturb by itself.